Overdrive off on matrix, going faster ?

[trixareforme]

Ok, i have a 2003 matrix xr. when im on the freeway trying to see how fast i can go , i feel i have more power when i have my over drive off. then when my Rpms get to high, i switch my overdrive on. then keep accelerating. is this bad to switch my overdrive on while going this fast ? plus toyotas are automatically put on overdrive, is it bad for me to drive it off ?

[curtis73]

Nope. The faster you rev, of course, the greater the wear on the engine, but that is true of any gear or any speed. The reason the acceleration feels stronger is twofold; first, your engine makes more power up high in the revs, and second, the higher gears have less torque multiplication, so the net torque making it to the wheels is reduced by about 1/4

[trixareforme]

so its ok to switch my overdrive at a high speed ?

[trixareforme]

ohh and thanks for all ur replys dude u help everyone out , thats cool, ur a like a automotive information Wiz.

[curtis73]

Originally Posted by trixareforme

ohh and thanks for all ur replys dude u help everyone out , thats cool, ur a like a automotive information Wiz.

Wow, thanks. I wouldn't go as far as Wiz, but you're welcome

Its fine to shift your tranny in and out of OD. During shifts is when 90% of the wear occurs in an automatic tranny. They're of course designed to handle it and the wear that occurs during the shift is incredibly minimal, but it stands to reason that a transmission has a certain lifespan and the fewer shifts, the better. Most cars also have a protection factor built into the computer that it won't let you shift down if the shift would cause the engine to rev past redline so for the most part you can't damage it. You'll just be accelerating wear on the components.

[Quickshift]

if a transmission is 4 speed w/OD is the OD gear 4th? or is it one more gear so it becomes a 5 speed

[solaris=amazing]

A 4 speed Automatic OD transmission i believe is 3 gears, with overdrive as a 4th gear-i believe it's a band though, so technically it's a 3 speed trans, with an extra band-4th(or overdrive).

I can be wrong... Curtis is the man for answering questions.

BTW, when i'm going to be driving on normal, light to light streets (not over 50mph) i'll keep OD off, this does make your gas mileage go down though...atleast it did with me, i got a 4.6L v8 Tbird that eats up gas more with od off. When your going over 50mph for a while though, leave OD ON, believe me, cause you will take a hit in the wallet-because of the gas.. If you have alot of people in the car, leave OD off under 50..over 50...put it on.

[solaris=amazing]

PS trixareforme, yeah my car feels more punchy also with od off, i love the power.

Someone told me when you take off o/d, you are just eliminating the final gear...and there is NO differance in speed....BULLSH*T..lol... If i'm going 60/70mph..and punch it, with o/d off..MUCH faster. It's what curtis said, about the rpm's staying higher near your power band. My torque peaks at 3200..

[curtis73]

You're right Solaris... Its a four speed tranny; fourth is the band which overdrives it.

[Quickshift]

thx for clearing that up
btw when you put OD off your basically downshifting which raises your RPM therefore giving you more power. For example my parents have an 03 Rav 4 on the highway if there is an incline, like the one on I-15 to vegas from socal you put OD off and you can get up 90 or 95 on those inclines.

[curtis73]

... And in theory, you'd be in 3rd (drive) anyway since the automatic tranny would shift there for you. There is no difference between physically putting the shifter in the third gear, and the transmission doing it on its own. It doesn't have more power if you put the shifter in D vs. letting the tranny do it for you. In general, it makes sense to put a tranny in OD and let it shift on its own unless its hunting around gears a lot.