3rd & 4th Generation (1992–1996 & 1997–2001)Toyota Camry Discussion for years: 1992-1996 & 1997-2001
Topics of discussion range from fuel economy, safety, modifications, performance all involving America's favorite family car, the Toyota Camry.
Just putting it out there that I have confirmed for myself that turning the Over Drive off reduces engine power output. ('93 3VZ-FE). For years I have wondered if it only limited the transmission to 3rd gear, or if it ALSO reduced engine power output. I would sometimes drive around with O/D off, and try to compare it with O/D on. It always sort of seemed that engine power would be reduced.......maybe a little?.....not much with O/D off. I installed a trailer hitch a couple of years ago and often tow a utility trailer and cargo, around 1500 lbs. I noticed while on the highway that as I climbed hills and passed with O/D off, in 3rd gear, it definatly didn't have as much power as with O/D on. So to confirm this, I compared (while climbing a long hill) with the transmission down shifted to 3rd gear on it's own, turning the O/D on and off. Remember the transmission is already in 3rd gear with the load of climbing the hill. Pushing the O/D on and off wasn't shifting gears, just telling the ECU that it was either on or off. There was a definate difference in the sound of the engine, and you could feel a noticeable drop in power output with the O/D off. I guess with the added load of the trailer made it very noticeable. So in conclusion, for maximum performance, keep your O/D ON!
i have an 02 solara sle, and no it doesnt, its the same on or off, because i drive around with it off most of the time in the city, and makes no difference.....
i think there maybe something wrong with your ride if you feel engine having noticeably less power with o/d off.
for me power output stays exact same and thanks to lower gear (and higher rpms) i actually get much more acceleration/power and better traction on ramp turns (e.g. downhill) than at same speed on higher gear (which is logical).
but when engine works on reduced gear already then switching o/d on or off doesn't make ANY difference at all.
__________________ '02 Solara SLE V6 1MZ-FE/A541E Coupe .: Denso/NGK : Akebono SP : Philips 9011 HIR (low+high) : Toshiba HIR2 9012 (fogs) : Magnefine :. @ 131k
'00 Solara SE 5S-FE/A140E Coupe .: NGK : Hawk HPS : Philips XP : RCEng : Magnefine :. @ 82k
4SALE: connectors for Camry Headlight Wiring Harness and ECU
Have ANY of you people pulled a 1500 lb weight behind your car, and then check for a difference? I will say again that I could hardly notice ANY difference without a TRAILER, but when towing it can be seen.
Have ANY of you people pulled a 1500 lb weight behind your car, and then check for a difference? I will say again that I could hardly notice ANY difference without a TRAILER, but when towing it can be seen.
...I may be pointing out the obvious, but perhaps it's that 1500lb trailer that's making your car feel slower and like it has less power?
In all seriousness, there is NO drop in power between having O/D off or on, unless your car is refusing to drop out of O/D in which case you would get _more_ power with O/D off which logically speaking, makes sense.
I don't know if you know if you've driven a car with a manual transmission, but it's like you're saying your car has more power to pass in 5th gear than 3rd or 4th. Not possible from an objective point of view, assuming your car is in working order.
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'05 2AZ-FE @ 47K miles | '95 1MZ-FE @ 92K miles moving forward
Again I will point out that I have a '93 Camry with the 3VZ-FE V-6. I have no idea if any engine other than this one is set up the same. An '02 Solara is a long way off from the old '92-'93 Camry, and such may not be programmed the same. The comparison I told you about in the original post was while towing the trailer up a long grade. Turning the O/D on and then off while the transmission was already in 3rd gear didn't cause the transmission to shift gears, just the O/D switch telling the ECU that it was either on or off. This did create a change in the sound of the engine and showed a slight drop in power when the O/D was turned off. Immediately turning the O/D on again would cause the tone of the engine to rise and it would pull a little harder. The difference is noticeable, but not big. I tried the same test today without the trailer and virtually found no difference with O/D on or off, and such won't matter to anyone if they don't pull a trailer. The next time I pull my trailer, I will try and record a video clip during the test. It seems this is the only way anyone will agree. (Not that it matters to me)
...I may be pointing out the obvious, but perhaps it's that 1500lb trailer that's making your car feel slower and like it has less power?
In all seriousness, there is NO drop in power between having O/D off or on, unless your car is refusing to drop out of O/D in which case you would get _more_ power with O/D off which logically speaking, makes sense.
I don't know if you know if you've driven a car with a manual transmission, but it's like you're saying your car has more power to pass in 5th gear than 3rd or 4th. Not possible from an objective point of view, assuming your car is in working order.
The ECU in a manual setup is different than an automatic setup. Engine power will only be affected or manipulated manually through mechanically changing gears and ratios. An automatic setup has the Transmission ECU built into the engine ECU, and as the results of my own testing shows some type of communication between the engine management programming and the transmission O/D status. I am not saying that my car has more power in a higher gear than a lower gear.....that's a no-brainer. I am saying that under heavy engine load (probably more load than will ever be placed on the engine other than trailer towing), while the transmission is already in 3rd gear and under a constant fixed load, the O/D status affects the engine management to cause a slight but noticeable decrease in power output with the O/D off. This is only noticable when the engine is under heavy load, which explains why no one here agrees or thinks it's possible. I have a '93 Camry with the 3VZ-FE V-6, I have no idea if other models other than this will do the same. If you don't have a 3VZ-FE, please don't say that it's not possible because your {whatever model} doesn't.
It's not possible, literally. Not because "my engine doesn't do it" (which is doesn't because I have a stick), but because O/D is like a fifth gear.
You get more power with it off because you only have four gears to choose from, not five. I don't know if it changes the rate at which it switches gears, but staying in 4th gear at 4200 RPM's is more powerful than 5th gear at 2500 RPM's.
It's not possible, literally. Not because "my engine doesn't do it" (which is doesn't because I have a stick), but because O/D is like a fifth gear.
You get more power with it off because you only have four gears to choose from, not five. I don't know if it changes the rate at which it switches gears, but staying in 4th gear at 4200 RPM's is more powerful than 5th gear at 2500 RPM's.
You are totally missing my point. Please Re-read all of my posts.
As a former mechanic and life-long car geek, let me affirm the correct answer...
In a typical transmission, manual or automatic, all gears below "HI" are reduction gears. They make the final drive speed (the drive shaft if you have one, or simply the pinion gear) spin more slowly than the engine crankshaft. That multiplies torque for more pulling power and quicker acceleration. HI gear - NOT an overdrive - is usually a direct drive. There is no gear reduction, it is a straight coupling that keeps everything spinning at the same speed.
An overdrive, again it doesn't matter if it is manual or automatic, is the inverse of a gear reduction and causes the final drive to go FASTER than the engine. This slows the engine down which allows it to save on fuel. It also cuts your acceleration to almost none. That is why you need to shift down to a lower gear (in automatic terms that is "passing gear") in order to accelerate to pass a car or climb a steep hill.
****** If you have an automatic transmission, go ahead and leave it in overdrive if you are not towing. It will only shift into that highest gear if conditions permit. You will not "force" it into selecting the overdrive gear if you are going too slowly or lugging up a hill. *****
Thanks for the quote, but you should also give credit to the source. Again, my point has nothing to do with gear ratios, Higher gears versus low gears or an over drive inverse ratio. My point has to do with the O/D status telling the engine ECU that it is either on or off, and then the engine ECU responding by giving a different fuel/ignition timing output to the engine and giving a slightly increased level of performance with the O/D on and reducing engine performance via a slightly different fuel/ignition curves with O/D off. This has nothing to do with which gear the transmission is in, it has to do with engine fuel/timing curves and a slight adjustment in engine management.
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