Chevy Cavalier 2004 (or 2003) : good car?

[CougTek]

My current car seems to have been a mistake. While it's not really old, many parts break and I'm starting to be fed up (don't ask, I don't tell what I'm driving now). Sooner or later, knowing myself, I know it will end up in a parking lot at the early morning hours and taste my sledgehammer when it will have failed me one time too much.

Since I'm an environmentalist, I'm only interested in cars with low fuel consumtion. And since I'm broken, forget BMW even if their 3 Series have low fuel emissions. So I'm looking for a car with a low price and not very fuel-ungry. Reliability is another big point. Performances are less important. I know I have a heavy foot, so a car that is boring to drive would probably be better for myself since I would be less tempted to push it. However, I need enough torque not to have to play with the gears to maintain speed on rising roads.

If I can wait at least one year, the car that I plan to buy is the upcoming Toyota Prius. It is supposed to make over 60mpg while its combined electrical/fuel-based motor power will be around 130hp, so it will be less under-powered than the current version. And since it's a Toyota, it cannot be fun to drive, so I shouldn't be worried of tickets while I'll sit behind the wheel. But the new Prius model is still one year away according to what I read. If I bring my car in a parking lot before that, I'll need to opt for something else...

...There comes the new Cavalier. It has a new look compared to the older generation. I think, but I'm not sure, that it has a redesigned chassis that offers a better rigidity (better security and handling, I guess). Motor doesn't seem to have changed compared to last year model. Still at 140hp. Enough for my needs anyway. Why am I asking about the Cavalier instead of other small cars with a better reliability reputation like the Sentra or Civic? Because GM currently offers 0% financing for up to 5 years and it is about the only car I could currently afford without having to eat only white bread and rain water.

In the past, most comparative reviews I've read placed the earlier Cavalier models consistantly being most competing small cars models. Chassis was flimsier, motor was noisy, reliabilty, while not horrible, wasn't up to Japanese standards and handling was never better than middle-of-the-pack. I would like to know if it has changed with the newer model (did it changed in 2003 or 2004 edition?)? I'm sure Clocker will have an opinion about it.

The only other serious contender, apart from the not-yet-here Prius, is perhaps the new Nissan Sentra. I plan to try both the Sentra and the Cavalier soon (before snow falls) to get a better idea, but your opinons would be appreciated.

Don't mention Hyunday. They screwed my government by getting a 400 millions check in the late 80's and not building the fab they were supposed to, so I'll boycott them for the rest of my life. Besides, I don't like the idea of owning a car that I know will have more rust than intact metal after five years.

 

[Buck]

Skoda . . . oh sorry, wrong country.

 

[P5-133XL]

If you can't afford new - Try used. That option is better than eating bread and water. It is also better than choosing the car you buy by its price. You will have a larger pool of cars to choose from. You've gotta be careful because there are pitfalls with used cars but if you are careful you can also get a good bargin.

That being said, I don't personally know anything about the Cavalier. I'd use Consumer Reports as a good example of an independant organization with good reliability data.

 

[Howell]

Because GM currently offers 0% financing for up to 5 years and it is about the only car I could currently afford without having to eat only white bread and rain water.

I'd suggest you look into this further. No. 1 because Toyota is offering a .9% rate here in the states until Sept. 2. No.2 because the monthly payments are still not insignificant. At the bottom of the TV ad is says the payments are something like $16.23/month for every $1000. I've been looking at these deals too.

Also be aware that the Prius interior is thought to be ugly compared to other hybrids.

 

[Howell]

Addendum: I wonder if the "Certified Used" vehicles qualify for the low interest rate.

 

[CougTek]

A Corolla 2004, for instance, would cost me around 60$/month more than the Cavalier and I haven't seen any 0.9% promotion around here for the buyout option. Besides, I don't think I'll buy something before at least November or December.

 

[Buck]

Consumer Reports -- 2003 Cavalier:

The Cavalier and the similar Pontiac Sunfire are unpleasant, crude, and outdated. The 140-hp four-cylinder engine performs well enough but is noisy when revved. The Cavalier's virtues are quick acceleration, respectable fuel economy, and a smooth automatic transmission. The ride is stiff, uncomfortable, and lacking in control. Front seats lack support, while the rear seat is barely adequate. Interior fit and finish are decidedly inferior. Antilock brakes are no longer standard, removing one of the Cavalier's few advantages. A poor frontal offset-crash performance is another detriment. The Z24 model was replaced by the LS Sport.

The Chevrolet Cavalier’s few virtues include quick acceleration, reasonable fuel economy, and a smooth transmission. But it’s a cramped and noisy car that feels dated and flimsy and doesn’t ride well. Access is difficult, the seats are uncomfortable, and interior quality is crude. Reliability has been average lately.

Last year the Cavalier got GM’s 140-hp, 2.2-liter Ecotec engine (the same as in the Ion). For 2003 it received a mild face-lift. We chose the midtrim LS, which included ABS and power windows, locks, and mirrors. It starts at $15,630. With an automatic or side air bags, it came to $17,370, including shipping. The CR Wholesale Price is $15,759. With discounting, we paid about $15,000 last fall.

FEATURE REPORT -- Consumer Reports

March 2003

Ratings Small sedans

Among small sedans, many models are better choices than the five tested for this report. Both the Honda Civic EX (about $18,500) and Toyota Corolla LE (about $17,000) are well made and reliable. The Civic is nimbler and has a better driving position; the Corolla is a bit quieter. Other options are the Nissan Sentra (about $16,500) and Mazda Protegé (about $16,900), which have shown good reliability.

In terms of overall performance, the agile and roomy Ford Focus ($16,000 to $17,500) has topped our Ratings, but persistent reliability problems keep us from recommending it.

Used-car alternatives: Good late-model family sedans, such as the Honda Accord or Toyota Camry, can be had for about the same price as our test cars.



Small sedans (Listed in order of overall score)


Ford Focus ZTS $17,385

Honda Civic EX $18,320 (Recommended)

Toyota Corolla LE $17,051 (Recommended)

Hyundai Elantra GLS $14,749

Subaru Impreza 2.5 RS $20,420 (Recommended)

Mazda Protegé LX $16,965 (Recommended)

Nissan Sentra GXE $16,517 (Recommended)

Suzuki Aerio GS $16,294

Mitsubishi Lancer LS $18,167

Hyundai Accent GL $12,659

Saturn Ion 3 $17,565

Dodge Neon SXT $16,275

Chevrolet Cavalier LS $17,370

 

[Buck]

. . . of course, those are U.S. prices listed.

 

[e_dawg]

I'm only interested in cars with low fuel consumtion ... However, I need enough torque not to have to play with the gears to maintain speed on rising roads.

Fuel economy and torque are often mutually exclusive unless you get a diesel. Most Japanese 4-cylinder engines in their compact cars are gutless wonders when it comes to torque. If you get a bigger engine for the torque, however, fuel consumption tends to increase. Timwhit's Nissan Sentra has a torquey 2.5 L inline-4, but it uses quite a bit more fuel than Honda's 1.7 L engine. Not bad, however.

Volkswagen's Golf GL TDI would be the car that best combines fuel economy and torque. 46 mpg and 150 lb-ft of torque. The 2004 model should arrive in October and come with 177 lb-ft of torque and still get about 45 mpg! The only problem that you might have with a diesel is the fact that Quebec is pretty cold in the winter. Diesel fuel gels below -20 C unless you use diesel additives and a diesel engine is more difficult to start in very cold weather. Today's diesels do not have as much of a problem in cold weather -- for example, I would get a TDI in Ontario without any hesitation whatsoever, but when it comes to Quebec, I would think twice about it. (I've heard there are quite a few people who have no problems with their TDI's in Quebec, though.)

Otherwise, your best option just might be something like Timwhit's Sentra. Mediocre fuel economy (for that class), but excellent torque. And reliable.

Unfortunately, you won't find any good deals on used Japanese cars -- they retain so much of their resale value over time it's ridiculous. I would recommend buying American for used cars. A 2 year old Grand Am, Alero, or Malibu would be my recommendation. Possibly a 3 year old Grand Prix. While these cars are not the best when it comes to fuel economy, they are surprisingly good considering the amount of torque that they produce.

And lastly, the 2004 Cavalier is essentially unchanged from before. It does, however, have a surprisingly excellent engine. Good torque AND fuel economy. The rest of the car is mediocre, however. Nevertheless, if that's the only car you can afford new, that's not a bad choice.

 

[Fushigi]

http://www.edmunds.com has lots of good info about cars. Pricing would be US-centric, but there should be a wealth of info in the reviews, test drives, and perhaps most useful the discussion areas. Also check their true cost of ownership calculator. It'll factor in economy, insurance costs, etc. to give a better picture over a long period of time.

 

[Pradeep]

I believe the Cavaliers have a problem with failing alternators.

Mitsubishi currently has $0 down and 0% financing in the US, do they have anything going in Canada?

 

[jtr1962]

Coug,

It sounds to me like you really have your heart set on the Prius, so why don't you try to nurse your car through the next year or so and just get that? Or maybe if fuel prices keep going up like they have been around here(gas jumped from $1.92 to $2.09 per gallon in one week) more automakers will start making hybrids and you'll have a wider choice. I think it's a shame that nowadays a person can't get a car with 80 to 100 mpg even though the technology is readily available. Performance and fuel economy shouldn't be mutually exclusive, either, as I've discussed many times.

Another question-what are your usual driving habits? Do you regularly make round trips of more than 60 miles? If not you might want to consider a straight electric. Just plug it in overnight when you get home. No emissions, no worrying about fluctuating gas prices. I'm amazed that electrics have't caught on in cities like New York where most trips are under 20 miles, speeds aren't very high, and pollution is a problem. Another factor to consider is that acceleration-wise electric motors are equal to a gas engine of about twice the power due to their enormous torque at zero RPM.

I'm further guessing by your posts that you fall into the school of it's more fun to drive a slow car fast than a fast car slow. I agree, especially since I regularly "drive" what is probably the slowest vehicle around except for Segways and electric wheelchairs.

 

[Buck]

I believe the Cavaliers have a problem with failing alternators.

Mitsubishi currently has $0 down and 0% financing in the US, do they have anything going in Canada?

Be careful with Mitsubishis. Due to their alliance with Daimler-Chrysler, some Mitsubishis have Chrysler transmissions -- that is a big no-no. Chrysler transmissions have had a very poor reliability rating for the past two decades. This I have experienced first-hand in the past couple of years at transmission shops.

 

[e_dawg]

Just like with diesel, hybrid and especially pure electric cars have trouble with very cold climates like in Quebec. Batteries do not take a charge nor do they produce a charge very well when it's cold. You will be running the gas assist-engine quite often to compensate for the cold-weakened batteries in a hybrid, and you will have a pathetic range with a pure electric. This is not to say that you cannot run a hybrid (or even a pure electric) in Quebec, but it won't be as great as in a warmer climate.

Actually, scratch that. You probably cannot run a pure electric in Quebec successfully. On a cold winter's night, you will not only have trouble keeping the inside of the car warm, but you will run our of battery power trying.

The hybrid? I'd think twice about it, but it would probably work just fine... just not as good fuel economy as you would expect. (And despite the characteristic for electric motors to produce peak torque right from 0 rpm, you will still need to downshift when going up hills, as the electric motor only provides something like 10-15 lb-ft over the existing 70-80 something of the puny gas-assist engine)

 

[Fushigi]

Be careful with Mitsubishis. Due to their alliance with Daimler-Chrysler, some Mitsubishis have Chrysler transmissions -- that is a big no-no. Chrysler transmissions have had a very poor reliability rating for the past two decades. This I have experienced first-hand in the past couple of years at transmission shops.

While DC still owns a decent percentage of Mitsu, I think the DC-Mitsu relationship has cooled some since Benz moved in. There is still platform-sharing (Sebring etc. and Galant & Eclipse), but DC seems to be moving stuff from the Benz lineup into the Pentastar house. To my knowledge, Lancer & Galant don't share any powertrain components with DC. Lancer is a 120HP 2L 4 cyl; Neon and the Neon Wagon (PT Cruiser) use a 150HP 2.2L IIRC. I think DC is using a 2.7L V6 in Sebring-size vehicles; Mitsu uses a 3L in the Galant & Eclipse.

I definitely agree, though: Avoid DC transmissions. In the late 80s/early 90s they were replacing the trans on some minivans at the rate of approx. 1 trans/2500 miles.

Full disclosure: I have a 99 Galant (first year of the 99-03 style) and have had 78K trouble-free miles. Beyond the scheduled maintenance I've replaced a piece of trim. That's about it. After this experience, I would easily consider buying another.

FWIW, Mitsu is also offering a 7yr/70K mile powertrain warranty in the US.

 

[jtr1962]

(And despite the characteristic for electric motors to produce peak torque right from 0 rpm, you will still need to downshift when going up hills, as the electric motor only provides something like 10-15 lb-ft over the existing 70-80 something of the puny gas-assist engine)

I thought hybrids don't have a direct mechanical link between the engine and wheels. I was under the impression that electrical motors drive the wheels(either directly or through a one-speed gearbox) and receive their power from the battery which in turn is recharged via the gas engine powered generator(diesel-electric locomotives have worked like that, minus the battery, since the early 1940s). Or at least this is how it should work since you can do all sorts of sophisticated antislip traction and braking, as well as regenerative braking(the motors act as generators, slowing the car and pumping energy back into the battery). Please don't tell me all they're doing is connecting the electric motor to the drive shaft, perhaps via another set of gears so the speed matches the gas engine. A gas engine has just about the worst characteristics possible for acceleration purposes(i.e. max torque and power occurs within a narrow RPM range, necessitating a complex multispeed gearbox, and even then you only put on average maybe half the peak power to the wheels). If so, hybrids have a way to go before they're viable. Maybe we should just throw more money into making hydrogen fuel cell vehicles viable instead. Hybrids always struck me as a halfway house anyway-less emissions but nevertheless they still throw junk in the air. Of course you have to get people to care about emissions in the first place, which sadly scant few do these days.

Sorry, I forgot that cold climates and batteries don't mix, although lithium ion should do fine in cold climates if it can be made cheap enough.

What do you think of the idea of just laying wires under roads and having cars get electrical power via inductive pickup? Seems like a nice way to get the benefits of all-electric cars without the complex hassles of hybrids or a (so far) fruitless search for an ideal battery technology. I often wonder why this wasn't done in the 1950s when the Interstates were built and cheap nuclear generated electricity was all the rage. It would have added only a few percent to the project's cost. If you rode around on electric-powered trains(either third rail or catenary) for any length of time you would see why I think this mode of power is so great compared to gas engines and mechanical transmissions. The equipment is much cheaper to run compared to their fossil fuel powered cousins as well. Heck, the new AC motor locos don't even have brushes or a commutator to worry about.

 

[Pradeep]

Until Sept 2nd (and I'm sure beyond) Mitsu is 7yr/100K powertrain warranty.

 

[mubs]

What do you think of the idea of just laying wires under roads and having cars get electrical power via inductive pickup?

Reminds me of the good old (yes, I'm that old) days of AC vs DC. Edison promoted DC and had cables (that transmitted DC) buried at a shallow depth in the sides of the streets. Many a horse got electrocuted when it rained.

Would this be a problem these days as well, jtr?

 

[jtr1962]

That was the point of suggesting inductive pickup(which necessitates AC power) and using buried, insulated cables. You could just as easily have metal rails on the surface of the road and contact shoes on the cars(just like the amusement park kiddie car rides) but should a pedestrian trip crossing the street and touch two oppositely charged rails simultaneously...:bibber: Also, with an insulated cable there is much less chance of a road crew killing themselves repairing a pothole.

Speaking of horses, there is an interesting true story about how the horses learned not to step on both trolley rails at the same time in order to avoid a shock(or worse). The strange part is that when new horses were bought in fresh from the farm(where there were no rails to avoid) they immediately avoided stepping on both rails at the same time as well. Apparently the other horses somehow communicated this to them.

 

[Pradeep]

I'd be happy if they upgraded the Thruway E-Z pass system so that one could keep driving thru the EZ pass lane without slowing to 5 MPH. Of course given the sheer stupidity of some of the booth workers "hey why look if a car is coming before I step out on the roadway" I guess this won't be happening anytime soon.

In Mel they have a system set up so that you drive under the antenna at full speed (110KM/h). Of course there you MUST have an etag, there's no cash option.

 

[Howell]

(And despite the characteristic for electric motors to produce peak torque right from 0 rpm, you will still need to downshift when going up hills, as the electric motor only provides something like 10-15 lb-ft over the existing 70-80 something of the puny gas-assist engine)

Toyota designed the 1.5-liter engine in the Prius to run at a maximum speed of only 4,500 rpm, where it makes 70 horsepower. Keeping the maximum speed of the engine low allows for the use of lighter components that improve efficiency.

The electric motor on the Prius is rated at 44 horsepower from 1,040-5,600 rpm. It produces 258 pound-feet of torque from 0 to 400 rpm, which is more than enough to get the car going without the aid of the gasoline engine.

http://auto.howstuffworks.com/hybrid-car9.htm

 

[e_dawg]

The electric motor on the Prius is rated at 44 horsepower from 1,040-5,600 rpm. It produces 258 pound-feet of torque from 0 to 400 rpm, which is more than enough to get the car going without the aid of the gasoline engine.

Yeah, obviously Toyota are measuring HP and torque differently than they do gas/diesel engines -- the new Prius supposedly pumps out 67 HP and 295 lb-ft of torque. Either way, these numbers are ridiculous if you take them the same way as you would a gas/diesel engine. 258 lb-ft of torque would rip the Prius CVT to shreds -- even Audi, the world technological leader in CVT, cannot supply a tranny that can handle 258 lb-ft of torque, and their existing CVT unit is the most robust CVT to date by far. 295 lb-ft? You want instant fireworks? Don't make me laugh.

Okay, so my 10-15 lb-ft guesstimate was incorrect; turns out I was actually thinking about the Civic Hybrid's electric motor's horsepower at the time. The Civic Hybrid electric motor pumps out 13 HP and 36 lb-ft of torque -- and these numbers are far more believable than Toyota's.

 

[e_dawg]

I'd be happy if they upgraded the Thruway E-Z pass system so that one could keep driving thru the EZ pass lane without slowing to 5 MPH. Of course given the sheer stupidity of some of the booth workers "hey why look if a car is coming before I step out on the roadway" I guess this won't be happening anytime soon.

In Mel they have a system set up so that you drive under the antenna at full speed (110KM/h). Of course there you MUST have an etag, there's no cash option.

In Toronto, our 407 ETR (Electronic Toll Road) highway can collect money by photographing cars' rear license plates from overhead cameras at each entry and exit point. They mail a statement to your address every month to collect. However, this method incurs a $5 administrative fee (or whatever it is; I forgot exactly). The preferred method for frequent users is to purchase a transponder that you stick on your dash or windshield that automatically signals your entry and exit to the transponders located at each entry/exit point along with the cameras.

 

[e_dawg]

Oh, and if I wasn't clear, there are no toll booths. Everything (photographic and transponder logging) is done as fast as you can drive (often >140 km/h on the 407).

 

[jtr1962]

Just to correct one thing, the torque curve of an electric motor is way different than that of a gas engine. A gas engine has a torque curve that looks somewhat like a flattened parabola with the maximum occurring slightly under the maximum power RPM. To a first approximation it is a constant torque device. An electric motor, on the other hand, is a constant power device. Horsepower=2*pi*torque(in ft-lbs)*RPM/60*375 for any type of prime mover, gas or electric. Therefore, the 44 HP electric motor of the Prius develops 151 ft-lbs of torque at 1040 RPM but only 28 ft-lbs at 5600 RPM. The maximum(258 ft-lbs) is only developed within a very narrow speed range(0 to 400 RPM). This may overload the continuous ratings of the CVT briefly, but the car soon accelerates and the motor torque quickly drops to levels that the CVT can handle continously. One other slight complication is that going by my equation, the torque becomes infinite at 0 RPM. Obviously it doesn't since the motor winding resistance and battery resistance can only supply a finite amount of current. In fact, the HP of the electric motor is less than rated at low RPM because of this fact. 258 ft-lbs torque at 400 RPM is only 29 HP. This falls linearly to 0 HP at 0 RPM.

 

[Fushigi]

Either way, these numbers are ridiculous if you take them the same way as you would a gas/diesel engine. 258 lb-ft of torque would rip the Prius CVT to shreds -- even Audi, the world technological leader in CVT, cannot supply a tranny that can handle 258 lb-ft of torque, and their existing CVT unit is the most robust CVT to date by far. 295 lb-ft? You want instant fireworks? Don't make me laugh.

Nissan Murano: 246#-ft with a 3.5L V6 & CVT.

 

[Howell]

I often wonder why this wasn't done in the 1950s when the Interstates were built and cheap nuclear generated electricity was all the rage. It would have added only a few percent to the project's cost./quote]

Considering the cost of copper, I doubt it would have only been a few percent. And then, when did they switch from aluminum wiring to copper. The technology available for resurfacing roads is still not such that one resurfacing would take you out of range of the line without even more significant power required.

The interstate highway system was built as a thoroughfare for military transport and a way to fend off a possible re-depression after WWII.

http://www.tfhrc.gov/pubrds/summer96/p96su10.htm
http://www.fhwa.dot.gov/infrastructure/history.htm

 

[jtr1962]

Considering the cost of copper, I doubt it would have only been a few percent. And then, when did they switch from aluminum wiring to copper. The technology available for resurfacing roads is still not such that one resurfacing would take you out of range of the line without even more significant power required.

Actually, if the voltage was high enough you might have been able to get by with very thin wires, or perhaps a large very thin flat plate the entire width of the road(like a sheet of aluminum foil). Not very significant cost-wise, and the highways should have been built better anyway to eliminate the need for constant resurfacing. The Roman roads are still used 2000 years later. Surely we can build a road nowadays to last just as long. As for the range, a few feet should be close enough for the inductive pickup to work if the frequency and voltage are high enough. Interestingly, one of the first proposals for distributing power involved using high frequency AC transmitted through the air. This worked surprising well even in the early 1900s and would have avoided the tangled mess of wire everywhere. The power companies didn't like it because they had no way to meter their power so in the end power lines won out although AC prevailed due to the ease of transforming voltages. Think how much less cluttered our landscape might have looked with the other scheme, although sadly the concept of paying for electricity when it should really be free(along with public transit) won out. In any case I think we're ultimately headed away from a centralized power distribution scheme once low-cost solar cells(and by extension nearly free power) are a reality.

 

[e_dawg]

Either way, these numbers are ridiculous if you take them the same way as you would a gas/diesel engine. 258 lb-ft of torque would rip the Prius CVT to shreds -- even Audi, the world technological leader in CVT, cannot supply a tranny that can handle 258 lb-ft of torque, and their existing CVT unit is the most robust CVT to date by far. 295 lb-ft? You want instant fireworks? Don't make me laugh.

Nissan Murano: 246#-ft with a 3.5L V6 & CVT.

Wow, looks like I'm behind the times. Ever since Audi came out with the CVT mated to the 3.0 L V6 found in the A6 and A4 in 2001, it looked like Audi showed the world who's boss when it came to CVT's:

Most previous CVTs use a steel V-section belt invented by Dutch CVT specialist Van Doorne. How much torque the CVT withstand depends on the design of belt, which at its best (Nissan Primera) is 150 lbft. Instead, Audi developed a chain to replace the belt. The steel chain consists of 1025 link plates and 75 pairs of pins. It is almost as flexible as the V-section belt but much stronger. Therefore it can handle up to 221 lbft of torque.

--AutoZine Technical School

However, little did I know that Nissan was working on a completely new technology that did away with the fragile and limiting drive belts:

If Audi’s Multitronic is an evolution of the conventional CVT, Nissan’s Extroid is obviously a revolution. Instead of using a belt or chain as the media for varying transmission ratio, it uses two pairs of rollers. As shown in the picture, the rollers link between the input disc (which connects the crankshaft) and output disc (which connects the driveshaft). By varying the angle of rollers, different transmission ratio can be obtained. For example, for "low" gearing ratio, the rollers meet the input disc near its inside diameter, but meet the output disc near its periphery; thus the output disc turns much slower than the input disc. The overall ratio range is 4.4:1.

Compare with belt or chain, the solid rollers can withstand much higher torque. Moreover, since the input and output disc are located at the same axis, it is able to be packaged in a longitudinal gearbox and drive the rear wheels. In fact, it is already driving the Cedric / Gloria in Japan, handling the massive 286 lbft of torque from the turbocharged VQ6

--AutoZine Technical School

And Nissan has managed to use CVT with AWD as well! Audi could only make it work with FWD. Who would have thought Nissan had the technology? I'm impressed.

 

[e_dawg]

In any case I think we're ultimately headed away from a centralized power distribution scheme once low-cost solar cells(and by extension nearly free power) are a reality.

Let's not forget fuel cells for residential and diesel co-gen plants for industrial units.

 

[e_dawg]

Just to correct one thing, the torque curve of an electric motor is way different than that of a gas engine. A gas engine has a torque curve that looks somewhat like a flattened parabola with the maximum occurring slightly under the maximum power RPM. To a first approximation it is a constant torque device. An electric motor, on the other hand, is a constant power device.

Thank you. This is a crucial piece of information that I sadly did not know.

In this case, I wonder why you dislike hybrids. They blend perfectly the two completely different torque characteristics of the electric motor and the gas engine to capitalize on the advantages of and mitigate the weaknesses of each other. Perfectly complementary, IMO.

You can rely on the electric motor to provide the torque at low rpm's, where a typical gas engine is very weak, and you can rely on the gas engine to provide the torque at high rpm's where an electric motor is very weak. Given large enough electric and gas engines, you can get the performance when you need it and you can get the fuel economy when you need it. We might be able to get a 35 mpg hybrid sports car with excellent performance!

 

[Mercutio]

GM product. Case closed.

 

[e_dawg]

A gas engine has just about the worst characteristics possible for acceleration purposes(i.e. max torque and power occurs within a narrow RPM range, necessitating a complex multispeed gearbox, and even then you only put on average maybe half the peak power to the wheels).

That's not as true these days with such innovations as variable intake geometry, variable ignition timing (and to take it further, Honda's i-DSI that is able to independently control dual spark plugs per combustion chamber), and variable intake and exhaust valve timing and lift (Honda's i-VTEC, Toyota's VVTL-i, BMW's Double VANOS, Porsche's Variocam, etc.). You get a huge power band with >85% of maximum torque available from 2,000 to 6,000 rpm in many cases.

 

[mubs]

Interestingly, one of the first proposals for distributing power involved using high frequency AC transmitted through the air. This worked surprising well even in the early 1900s

Amazing! I've always wondered about this; not so much for transmission from the powergen facility, but inside the house where it was inconvenient or impossible to have an outlet.

Please! Elucidate!

 

[jtr1962]

Amazing! I've always wondered about this; not so much for transmission from the powergen facility, but inside the house where it was inconvenient or impossible to have an outlet.

Please! Elucidate!

Our friend Tesla first thought of and attempted this. Here is a description of how the system works. He actually built and tested a working prototype of the system in Colorado Springs c. 1899. This account of his life tells of his many experiments, including that one(scroll about halfway down the page).

I'm not sure if the system could be cost-effectively made to work in a home, and the EM interference might make it impractical with today's reliance on electronics. Nevertheless, it was way ahead of it's time, and Tesla did succeed in making AC the standard of power transmission rather than DC.

BTW, when you mention that you're old enough to remember the good old days of AC vs. DC am I to assume that you're over a century old? (Just kidding). :lol:

 

[jtr1962]

In this case, I wonder why you dislike hybrids. They blend perfectly the two completely different torque characteristics of the electric motor and the gas engine to capitalize on the advantages of and mitigate the weaknesses of each other. Perfectly complementary, IMO.

It's not that I dislike them(I think they're cool), it's just that I tend to think that the R&D money might be better spent getting fuel cell vehicles to market sooner and speeding up the conversion to a hydrogen economy. That would also make US involvement in certain parts of the world unnecessary, so there are good geopolitical reasons for it as well. Maintaining as large an armed forces as we need to in order to protect our oil interests in so many far flung countries is a huge drain on the economy. I dare say that had that money been pumped into R&D over the last twenty years we might not even be having a discussion about hybrids since everyone would be driving them(or fuel-cell vehicles). Also, thanks for letting me know about the much flatter torque curves of the latest engines. Interesting to say the least, although by their nature gas engines are still more or less constant torque devices. To the best of my knowledge we've never made a gas engine that gets, say 3 times the torque at 2000 RPM as it does at 6000 RPM. A curve like that would make it a constant power device just like our friend the electric motor.

One last piece of info regarding electric motors is that as their RPM goes up eventually the back EMF approaches the supply voltage in magnitude and as a result very little current flows into the motor. Thus, past a point the power of electric motors starts to fall. A perfect example of this is the AEM-7 electric locomotive power curve that I recently helped someone duplicate for MS Train Simulator. The locomotive's power peaks at 6850 HP at 53 to 55 mph, and then starts to fall off, dropping to 5500 HP at 125 mph as the motors'(there are four motors of ~1750 HP peak, one on each axle) back EMF limits the current that can be drawn from the power supply. In effect, the apparent resistance of the motor goes up as RPM increases. Eventually, you reach a point where the motor draws just enough power to spin at high RPM, and the net shaft power is zero.

We might be able to get a 35 mpg hybrid sports car with excellent performance!

Or an SUV with similar fuel economy(I dislike SUVs but if people really must have them at least make them as fuel efficient as they can be). It's certainly worth pursuing the technology to some extent even if the ultimate solution is fuel cells. I can see lots of other uses for a CVT, for example. In fact, I want one for my bike, especially if it can be made without belts or chains, and combined with an automatic shifter that sets the ratio so that the pedals turn at any desired RPM(from maybe 60 RPM up to 150 RPM) according to the rider's preference.

 

[zx]

Coug, why not a Honda Civic Hybrid? You get excellent fuel economy and a good car, plus the fact that the a civic does not look wierd (or make you look weird).

The Cavalier did not undergo major changes recently. There was a minor face lift and the engine.

Our canadian government has a guide for fuel consumption here :

http://oee.nrcan.gc.ca/vehicles/guide/guide.cfm?Text=N

 

[e_dawg]

To the best of my knowledge we've never made a gas engine that gets, say 3 times the torque at 2000 RPM as it does at 6000 RPM.

But we make diesel engines with those characteristics all the time

A curve like that would make it a constant power device just like our friend the electric motor.

Honestly, I don't think we would want a constant power device to propel our cars. It would be quite boring... like piloting an electric tram car. After an inital surge, the "rush" would eventually go away. Most enthusiasts desire constant torque characteristics so that the engine "pulls" like a pitbull all the way to redline.

 

[jtr1962]

Honestly, I don't think we would want a constant power device to propel our cars. It would be quite boring... like piloting an electric tram car. After an inital surge, the "rush" would eventually go away. Most enthusiasts desire constant torque characteristics so that the engine "pulls" like a pitbull all the way to redline.

I think you've been misled a bit here. Most trolleys and electric MUs(i.e. subway cars) aren't really constant power. Rather, they have a quick burst of acceleration up to 20 or 30 mph, often at a constant acceleration rate, and then the power tapers off really fast after that, often to less than 50% of the power at 20 mph, in order to keep from overloading the substations. Simple physics, really. You get the most bang for the buck, energy-wise and travel-time wise, by accelerating to 20 mph as quickly as possible and then gradually building speed after that. No point using alot more energy to continue rapidly accelerating to maybe 60 when the stops are half a mile apart and you'll only shave maybe another 5 seconds. Most commuter rail MUs don't start tapering off until after 60 to 80 mph because of the greater distance between stations. Again, the idea is to use the energy where it makes the most difference.

Electric locomotives are closer to a constant power machine, but even here that's not always 100% true. For example, depending upon weight, wheelslip may limit power even at speeds as high as 60 mph. At very high speeds the power may start to fall off the peak as I described for the AEM-7 in my last post.

Interestingly, coupling a CVT with a gas engine will cause the car's acceleration to more resemble a constant power machine than a constant torque machine. When accelerating the engine will(presumably) remain at its peak power RPM while the CVT ratio changes as wheel speed changes. Sure, you'll have twice the pull at 30 as you do at 60, for example, but this situation isn't that dissimilar from going through the gears and upshifting at the redline. In fact, the CVT should be able to get more acceleration out of the same engine by virtue of keeping the engine at it's peak power all the time. This simply can't be done with a multispeed gearbox. You lose some power when the engine falls out of it's peak power RPM, and you lose again with the time taken to shift gears. True, you have a more or less constant pull in each gear, but since the RPM varies the power varies.

 

[e_dawg]

In fact, the CVT should be able to get more acceleration out of the same engine by virtue of keeping the engine at it's peak power all the time. This simply can't be done with a multispeed gearbox. You lose some power when the engine falls out of it's peak power RPM, and you lose again with the time taken to shift gears. True, you have a more or less constant pull in each gear, but since the RPM varies the power varies.

You're correct, of course, but CVT trannies have often been described as unsatisfying, despite the sometimes superior acceleration. It just doesn't "feel right" Admittedly, I haven't been in a CVT equipped car yet, so I can't say first hand, but a "car buddy" of mine and numerous automotive journalists have attested to that fact. Maybe everybody's stubborn and slightly irrational... although none of this should not surprise you when you see the public's insistence on purchasing hulking SUV's for god knows what reason...