johnnyluv82 wrote:
What is the difference in mpg between a stock 4 speed and changing to 5 speed?
if your moving a lot of cargo 5th. or go faster after you have 5th gear, you will get less mpg.
but if your mostly empty then youll get a small increse from the engine spinning about 250/400 rpms slower.
think about it.
if the in-put is spinning slower than the out put dosent it take more energy to spin it if the truck is loaded with a big load.
ah yea................
say your running 60mph with a 4 speed 3250~rpms and 4.11 gears. (tire size will make a diffrence). with no cargo just a driver and a full tank of gas. getting say 26~ mpg.
change to a 5 speed running the same speed, gears and load.
if you have a lite foot mabe youd go to 29~ mpg and be at 2,950~ rpms.the best MPG set up is the 3.42 rear end with the 4 speed trans and little 14" tires.
makes it hell starting out on a hill with very little cargo, and the gaps in the gears are gigantec.
this was the combo that isuzu sold in the pup as a MPG plus model for better mpg.if it was me and i had a 4x2 truck id change the rear to a 3.73 if it had a 4.11 or 4.55.
but if its a 4x4 then id go the 5 speed sence 4.11 are as good as it gets with them.
i hope this helps