Corolla v Civic v Hyundai/Nissan moeds

Not to sound condescending or anything, but I am glad you chimed in, because on further reading, I thought it should be pointed out that a major factor in automatics traditionally getting worse MPG is the torque converter. The TC represents a "fluid coupling," whereas the manual tranny's clutch etc. are a mechanical linkage. Energy transmission losses are greater with the liquid linkage. As many of the pros here know. (I am just an amateur who works on her own car and reads like crazy to understand it.)

But this has changed somewhat with the advent of the "lock up torque converter."

Optimal gearing is still said to be a factor, though. Several other factors are said to play significant roles, as well. So my post did not do justice to why older automatic trannies were less efficient than manual trannies.

Sure.

Just sort of randomly, based on checking this a few times in the last several years, and using only the same engine size for a given model:

2007 Civic, same engine size, both five forward speeds: Manual = 26 MPG city, 34 MPG highway Auto = 25, 36 2007 Subaru Impreza (an all-wheel drive vehicle) Manual (5-speed) = 19, 26 Auto (4-speed) = 20, 25 2007 Nissan Sentra Manual (6-speed) = 24, 31 Auto (variable gear) = 25, 33 2007 Hyundai Elantra Manual (5-speed) = 24, 33 Auto (4-speed) = 25, 33 2007 Kia Rio Manual (5-speed) = 27, 32 Auto (4-speed) = 25, 35

From this survey, I think we could argue that newer automatic trannies seem to do better at highway speeds, even though it often has fewer gears. The lock up converter (used only at higher speeds) is the first area I would explore to explain most of this higher efficiency. I see the lockup converter started gaining in popularity around the late

1970s but ISTM only recently did all models start having them. I see the 1995 versions of the cars above never saw the autos beating the manuals for miles per gallon. Granted other improvements may have been implemented, like continuously variable transmissions (CVT).

The Sentra is interesting, since for the two versions I compared, the big difference is the variable gearing in the auto. It's the only model that beat the manual version in both city and highway.

Toyota OTOH seems to consistently have no models where the auto does better than the manual under city or highway conditions.

Again, just an amateur here.

My Chrysler 4 sp automatic, which came out in the early 90s, has lockup on the top 3 gears. In effect it has 7 gears. The fuel mileage is excellent.

Josh S wrote in news:Josh- snipped-for-privacy@news.telus.net:

"lockup" doesn't change gear ratios,it just eliminates torque converter slippage. it "locks" the input turbine to the output turbine.

No "7 gears".

"Overdrive" would be "extra" gears.

Yep, I wish Toyota would have put that in as well. I a car as sophisticated as this one is, it should also be automatically driven. Tomes

You are rightly concerned about the batteries.

These 270 or so volt batteries have a list price in the $2500 range. They have 228 cells in series and only one needs to go bad to ruin your battery assembly. Newer models only use 201.6 volt batteries, ;)

Besides you have the $3400 list price for the inverter and $1100 for the generator module.

Though the warranty should do good, imagine getting hit with the prorated prices.

Think about all the dead weight you carry around, pollution issues (disposing of the battery), and then, having your system repaired in case of a failure. We all have heard the stories about a battery not charging, alternator issues etc with conventional cars. Think about a system many times more complex...

With all the problems fuel cells still have, I think hydrogen is the way to go.

Edw>>that's without any freaky driving techniques.

Yet, the individual cells can be replaced.

Yet, the technology has been proven and has been in use for over ten years (although not in the US during the first few years).

Why? Hydrogen is used to power fuel cells. And there is almost no infrastructure for fuel cells. Hydrogen has the problem that to make hydrogen, CO2 is generated, as well (i.e., using hyrdogen as a fuel still results in CO2 being produced).

Fuel cells have been used for year. In fact, the O2 tank that exploded on Apollo 13 when I was about four was used in two different types of fuel cells (mitochondria in the astronaut's bodies and the fuel cells that supplied electricity to the Aquarius and Odyssey).

When he wrote "in effect" he was probably right. Unless the RPM at lockup happens to match between one or more of those combinations, you get seven different "ratios" of crankshaft to ouput shaft speed, even though it doesn't happen because of gear ratios changing.

"mjc13" wrote in news:x4OWj.2122$za1.807@trndny07:

nope. wrongo. when the converter locks up,the crank RPM equals the converter output RPM,because they are -locked together-. No slippage.

after that,it's all gear ratios determining output shaft RPMs. fixed ratios.

Hydrogen can be produced pollution-free with solar cells. Solar array produces DC power. DC power is used to split water into H and O2. H is used in fuel cells or whatever. Heck, it burns nicely in internal combustion engines. Or externally in the Hindenburg. O2 is sold to NASA for their monkey business. What could be simpler? Alternative methods to produce energy are easy. All they require is our cleverness and industry. Tough part is the politics. Here in Houston the normal grocery-getter is an F-350 dually towing a boat. It is easy to hear its one passenger muttering about the high diesel prices to the clerk at HEB. The most gentle suggestion to this poor soul that perhaps a smaller vehicle might be in their enlightened self-interest and well.......you can imagine. We are talking about a driver who has a Ph.D. in engineering here. From Texas A&M. The best damn school on earth! Light rail, interurban, bike paths, golf cart trails, abundant plug-ins for the electric vehicles, efficient use of our rail freight system to keep the use of 18 wheelers to a minimum and a zillion other schemes (no hyperbole) will never come to fruition because we are too ignorant as a species. And too stubborn. On the topic of my 2003 Civic Si engine spinning too fast at 80mph: Is it possible and affordable to put a 6 speed in that little car? I'd be happier if its revs were closer to 2000 at 80 mph. Anyone have a referral for that project?

"Enrico Fermi" wrote in news:IcTWj.3149$ snipped-for-privacy@flpi148.ffdc.sbc.com:

I suspect the tranny from an RSX would fit in the Civic,it's a 6 speed,IIRC. Whether that changes the final drive ratio,I don't know.

you could always go to a larger diameter tire and recal the speedo.

That is one good idea. The larger tire would act to effectively lower my final drive ratio, thus slowing me down off the line. That might be a good thing :) My 64 VW 1.4 had a 4.11 gear and was quick until the rpm's ran out at 15 mph for the 1-2 shift. That flat four wasn't a real high revver. But, since I've done no homework at all, it is possible the six speed from the RSX could have the same ratios for 1st and 6th that my box has for 1st and

5th, but with closer ratios. That would do me no good at all for my plan. I should research the possibility of putting a taller 5th gear in my box. Perhaps that is possible? My first inclination is to just throw money at the idea and see what happens. I hope I know better than that......

"Enrico Fermi" wrote in news:x5YWj.3361$ snipped-for-privacy@flpi150.ffdc.sbc.com:

I doubt the gears would be available,and tearing apart your tranny would be a very complex task with a high chance for screwing things up. I would just swap the whole tranny,assuming the gear ratios were what you desire.(and as long as you're putting in the RSX tranny,the RSX-S motor would be a nice increase,too!)

BTW,is the motor in your Civic a K series? Other Honda motors rotate in the opposite direction,and are positioned 180 deg from the K series.

It seems my motor is a K20A3 which would swap with the RSX powerplant. I really feel insane contemplating that. I'll leave well enough alone for now :)

Are you deliberately misunderstanding us? Nobody claimed an overdrive type shaft speed ratio. What is being said is that when the lockup engages, you do in fact get the geared ratio - which you

*weren't* effectively getting with the converter unlocked. So for each gear in which the lockup works, you have two different shaft speed ratios: one with the lock off and one with the lock on. The *effect* is the same as having seven gear ratios, with *none* of them being an overdrive. I don't know how much clear I can make it...

"mjc13" wrote in news:a01Xj.5699$GK4.5024@trndny01:

It's still not any "effective gear ratio".It's just slippage.Wasted energy.

Whatever you have to say. Usenet never changes...

"mjc13 @verizon.net>"

"Elle" wrote in news:U83Xj.28460$ snipped-for-privacy@newsfe07.phx:

"Jim Yanik" wrote

In this context, where I think Josh was arguing the lockup feature increases the effective number of gears and so increases engine efficiency, I would not put it this way. The slippage is arguably infinite gears but not in a way that improves efficiency the way direct mechanical linkage (= lockup) to infinite gears would.

To split hairs.