Ok i have a question i have Jesse tune a pcm for me, only thing is i didnt tell him the Rear ratio. Is this a big deal? Cant he get all the info from the Vin. I already installed the pcm and seems ok just wondering if anyone could shead some light?

 

if you still have the stock gears, he has them on the VIN#, he gets all of your info fromt he VIN#, thats why he needs to know if you have done anything aftermarket.... so you should be ok...

 

sweet. Well in that case my RPM's have def dropped some on the highway.

 

[QUOTE=04BlackGmc]sweet. Well in that case my RPM's have def dropped some on the highway.[/QUOTE

does that smell like more mpg????

 

Did Jesse adjust for your larger diameter tires? Was your speedo adjusted for the larger tires in your previous tune? If not then that is why you are seeing less rpms on the highway.You are also going slower, than before the tune was adjusted, at the same indicated speeds. If the tune is properly set up for tire size and rear end gears then Jesse cannot make the rpms drop at a given speed unless the previous tune was not properly set up for those same parameters or Jesse's tune is in error.

 

Nope never got tuned for my tires because my speedo was never off, tested it many times.

 

What was the size of the stock tires on your truck before you went with the 285/75/16?

 

245/75/16

 

Your new tires are 2.3 inches larger in diamater than stock (30.5" vs 32.8").

 

yea i know that, thats why i never got why my speedo was still correct.