Considering a used 4Runner. What were '04 > '05 changes?

[T4RMatt]

My dad has a '05 Yukon Denali (4 speed) and its great off the line in first gear all the way to redline, which happens at about 45 mph, but when it shifts into 2nd it seems to fall out of the power range somewhat and takes a small amount of time for the engine to regain momentum. This is why I think more gears is better for acceleration. Fuel economy is better too because of the 5th overdrive gear.

This is actually a result of something GM uses called Torque Management on their fullsize trucks. It basically plays around with the timing to provide softer shifts to maximize tranny life. There are lots of reflashes availabe to get rid of this. I ordered a new PCM when I had my Silverado and it got rid of this problem.

 

[NCSCOTT]

Fuel economy is better too because of the 5th overdrive gear.

The Overdrive gear in the 4-speed is actually a higher gear numerically. Theoretically one would get better mileage with the higher gear if the engine is keep at a optimum RPM range (power band) for fuel mileage.

 

[tkr128]

5-speed does improve fuel economy although marginally. There's no difference between 2003-2004 and 2005 4WD models, both have 17/21 ratings. 2WD models are different though.: 18/21 for 2003-2004 and 18/22 for 2005.

 

[OUTRNNR]

The Overdrive gear in the 4-speed is actually a higher gear numerically. Theoretically one would get better mileage with the higher gear if the engine is keep at a optimum RPM range (power band) for fuel mileage.

The overdrive gear is taller, but the final drive is much shorter comparitively, therefore the difference results in more rpm/mph for the 4 speed, which in theory, reduces gas mileage. This is most likely the reason for the change in EPA hwy mileage from 21->22

 

[Koz]

The overdrive gear is taller, but the final drive is much shorter comparitively, therefore the difference results in more rpm/mph for the 4 speed, which in theory, reduces gas mileage. This is most likely the reason for the change in EPA hwy mileage from 21->22

NOT, if you look at the final gear ratio of the two trans', the 4 speed has a 3.90:1 final ratio and the 5 speed has a 3.72:1 ratio. So, The 4 speed will rev more or have lower MPH. Apparently it doesn't affect the gas mileage.

Koz

 

[OUTRNNR]

NOT, if you look at the final gear ratio of the two trans', the 4 speed has a 3.90:1 final ratio and the 5 speed has a 3.72:1 ratio. So, The 4 speed will rev more or have lower MPH. Apparently it doesn't affect the gas mileage.

Koz

Yeah, thats what I have posted!! More rpm per mph... Meaning more revs compared to less speed. This means at a constant speed the engine will be turning at higher rpms, or a a constant rpm, the speed will be less than the 5 speed.

Come on now Koz...

 

[NCSCOTT]

The overdrive gear is taller, but the final drive is much shorter comparitively, therefore the difference results in more rpm/mph for the 4 speed, which in theory, reduces gas mileage. This is most likely the reason for the change in EPA hwy mileage from 21->22

I understand your logic and agree with the theory. The only problem is did they put the same rearend gear behind the 5 speed with a V-6 as they did with the V-8 in 2005. If not and they stuck with the 3.909 my first post would be correct???? I do not know what gear ratios were used in 2005.

 

[OUTRNNR]

Who knows...I was basing my argument off the picture that was posted with the gear ratios. Not sure what year that is from...

 

[Fro-Runner]

Will someone please tell the Toyota corporation to send 03-04 V6 owners our 5 spd transmissions. I believe we have been waiting too long for the updated versions of these trannies.

 

[NCSCOTT]

Will someone please tell the Toyota corporation to send 03-04 V6 owners our 5 spd transmissions. I believe we have been waiting too long for the updated versions of these trannies.

LOL!!! Wishful thinking I am afraid. Well after all it is Christmas time it does not hurt to wish.