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10-30-2008, 02:40 PM
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#31
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Registered Member
Join Date: Jan 2007
Posts: 104
Country: Canada
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Quote:
Originally Posted by markweatherill
Hi swng, that two-speed Toyota transmission was probably the 'Toyoglide'. I owned a 1978 Civic with a similar two-speed and it was OK round town but at speeds more than 50mph it really became a buzz-box.
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Very true, especially about the buzzing which may indirectly mean relatively higher engine rpm, which could hurt FE ! But simplicity hopefully gives rise to reliability . That is of course only my wishful thinking. No matter what, talking about the 3-speed Corolla in question, a test drive plus a thorough inspection before buying are always good, especially considering that at least one post at above contains some not so favorable remarks about the reliability of a car belonging to that (or a similar) model.
I was thinking that if a 2-speed car could do reasonably well (in city, with not many chances to go over 50 mph), then probably a 3-speed one would do well enough to get by, perhaps even on highways. Of course, I was talking about cars made long long ago. Nowadays, we have every right to expect to drive more sophisticated cars.
Anyhow, the Corolla Matrix that I currently drive has only 4 speeds and I always long to have a 5th gear so that I can enjoy better FE and a quieter ride. You know, every time when I gently step on the throttle and the car responses strongly (relatively speaking), I would yell in my mind and say something like "Come on! I don't need such strong acceleration, but please give me a 5th gear with a taller ratio so that I can save some fuel!!!".
NB: Edited once for spelling.
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10-30-2008, 03:03 PM
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#32
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Registered Member
Join Date: Apr 2008
Posts: 6,624
Country: United States
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Quote:
Originally Posted by swng
Anyhow, the Corolla Matrix that I currently drive has only 4 speeds and I always long to have a 5th gear so that I can enjoy better FE and a quieter ride. You know, every time when I gently step on the throttle and the car responses strongly (relatively speaking), I would yell in my mind and say something like "Common, I don't need such strong acceleration, but please give me a 5th gear with a taller ratio so that I can save some fuel!!!".
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It seems to me that when they add another gear, they just make the gears closer together because people want close ratios. The 6 speed manual transmission available on a more expensive version of my 5 speed manual car doesn't have a taller 6th than my 5th, and I feel the same way about my 5th as you feel about your 4th.
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10-30-2008, 04:03 PM
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#33
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Registered Member
Join Date: Jan 2007
Posts: 104
Country: Canada
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TheHolycow! It is a always a pleasure to read replies by rational and insightful people like you and the many other members of this great forum.
What you said above cures my continuous craving for an additional gear to a great extent, as there is practically no hope of getting a taller ratio at the top gear anyway, short of modifying the car or switching to another car, if I understand you correctly. That is relief for my gravely bad feeling of having a 4-speed only transmission. I have to thank you for that . If the same is also true about the difference between the 3 and 4-speed Corolla, then the thread starter will have less to worry about getting a car with only 3 speeds .
However, curious as I am, I still look forward to seeing someone comment on whether, agility and smoothness aside, a car with less gear ratios will necessarily has its engine work harder on the road, as far as average rpm/FE is concerned . In other words, my question is: Will a 3-speed car's engine revolve the same number of times as that of a 4/5-speed car for an identical trip, all other things being equal? My intuition is a car with more speeds will still have an advantage. Yet that is of course another story.
Thanks again!
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10-30-2008, 05:23 PM
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#34
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Registered Member
Join Date: Apr 2008
Posts: 6,624
Country: United States
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I'm very interested in gears and gear ratios, so pardon me while I go on forever about this...
If my car was a 3 speed with the same 1st and 3rd was the same as my 5th, then it really wouldn't lose much efficiency. In fact, when it was new I experimented with different skip-shifting patterns, after reading about GM's CAGS system that disallowed drivers from using some gears during light acceleration in order to raise their sportscars' EPA ratings. Anyway, driving it as a 3 speed and even as a 2 speed gave me improvements, though I eventually decided to use all the gears -- I chose the manual transmission largely because I wanted to shift.
For a given trip, in my car, a 3 speed's engine would revolve the same number of times, since my 5th is so low anyway -- I can use it at 25mph, or if I'm looking for more acceleration I wait until I'm up to 30 before I shift into 5th. When do I ever drive slower than 25mph? Now, if there was lots of stop-and-go, then the engine would revolve more times given fewer ratios but the same low and high gears, because with the closer ratios I can keep it in lower RPMs during acceleration.
For cars with more widely spaced gears or less power, it could be possible that a 5 speed tranny would have a more appropriate ratio at a given speed (say, 35mph) than a 3 speed, which may have a gear slightly too high and a gear somewhat too low.
Again using the example of the VW Rabbit 5 speed vs. the VW GTI 6 speed, the engine revolves the same amount of times over the same distance in my 5th or the GTI's 6th. They both run 3000rpm at 70mph.
The transmission isn't the only place you can adjust gear ratios, though it's the only place with multiple ratios in most vehicles (exceptions include but are not limited to the VW GTI which has a two speed differential, and 4wd vehicles with a "Low" range option). The gear in the differential can be replaced, or you could change your tire diameter.
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10-30-2008, 06:00 PM
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#35
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Site Team / Moderator
Join Date: Sep 2008
Location: Northern Virginia
Posts: 4,742
Country: United States
Location: Northern Virginia
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Quote:
Originally Posted by swng
Will a 3-speed car's engine revolve the same number of times as that of a 4/5-speed car for an identical trip, all other things being equal? My intuition is a car with more speeds will still have an advantage. Yet that is of course another story.
Thanks again!
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More gears = more fun to drive.
-Jay
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10-31-2008, 12:07 PM
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#36
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Registered Member
Join Date: May 2008
Posts: 3
Country: United States
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As an owner of a '96 3 speed, the car does OK at high speeds.
I have driven it from NC to Florida 3 times and it gets around 28-30 round trip at 65-70 mph.
Now, I have just got a 2005 Corolla with a 4 speed auto and its getting 36-38 hwy mpg at 65-70 mph.
Around town, my wife is getting 24 mpg city, 5 miles to work.
I get around 30 mpg city driving 12 miles to work.
The 3 speed is something that I personally would avoid, just in principle of better mileage.
If fact, I didn't bother with looking at any 3 speed Toyota Corollas, while looking for a newer vehicle.
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10-31-2008, 03:00 PM
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#37
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Registered Member
Join Date: Jan 2007
Posts: 104
Country: Canada
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Quote:
Originally Posted by Jay2TheRescue
More gears = more fun to drive.
-Jay
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Can't argue with this . To The Moderatemiler, thanks for sharing your insight, again !.
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11-03-2008, 12:23 PM
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#38
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Registered Member
Join Date: Aug 2007
Posts: 1,069
Country: United States
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Quote:
Originally Posted by theholycow
I'm very interested in gears and gear ratios, so pardon me while I go on forever about this...
If my car was a 3 speed with the same 1st and 3rd was the same as my 5th, then it really wouldn't lose much efficiency. In fact, when it was new I experimented with different skip-shifting patterns, after reading about GM's CAGS system that disallowed drivers from using some gears during light acceleration in order to raise their sportscars' EPA ratings.[/sinp]
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Weren't people skipping shifts in Honda Insights to get better gas mileage? I agree as long as the final gear ratio is not too much higher in a 3 speed compared to a 4 or 5 speed your mileage won't very much, particularly if you are doing a lot of highway driving. I remember being disappointed and confused that a 6 speed Celica got worse mpg than the similar 5 speed Celica. Maybe the 6 speed had more horsepower, but I believe they were both naturally aspirated and had the same engine displacement. Also, I imagine a 6 speed transmission weighs more than a 5 speed. A 3 speed should weigh less than a 5 speed.
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11-03-2008, 12:58 PM
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#39
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Registered Member
Join Date: Apr 2008
Posts: 1,831
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I may be way off base with this but it seems like I remember them calling 4 speeds, 3 speed with overdrive.
I know my truck had a 5 speed and the 4th gear was 1:1 where as the 5th was 0.73:1 which meant that the motor shaft was spinning faster than the shaft to the differential.
I would think that the 3 speed wouldn't have the same spread as the 4 speed just because of the power (or lack there of) and the upgraded 3 speed with overdrive had the extra highway gear in it for better top end MPG.
I am assuming a lot here so I really don't know and without more information, that is what we all are doing. if you knew the gear ratios or trans numbers you could find out more.
it is my understanding that the 3 speeds didn't have an overdrive and if they did, it was actually a 4 speed.
just throwing it out there.
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11-03-2008, 05:16 PM
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#40
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Registered Member
Join Date: Nov 2006
Posts: 1,027
Country: United States
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Many of the later 3 speeds had a locking torque converter and when it locked up it "felt" like a 4th gear.
I think overdrive means that the drive shaft/intermediate shaft is turning faster than the crankshaft.
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