I'm gonna put 33s on my 2002 Quad Cab 4x4 3.9L. What mpg drop and power drop can I expect? And is their any way to make them better? Also I know the speedometer is gonna be off, but can I do anything to make it right, besides getting a GPS and looking at that for speed.

 

Power and mpg are both gonna suck. I dont have numbers to you but I can tell you with the 3.9 it'll suffer.

It won't be as bad if you have 3.92 gears or if you regear to 4.10

If you have 3.55 gears you'll lose your OD and put extra strain on your tranny.

You can bring your truck to the dealer and have the speedo recalibrated for some $$$. IMO just use a GPS one time and figure out how quick you're actually going and then compensate for it.

I plan on running 33x10.50x15 opposed to the more common 33x12.50...

Soon as I fix my rust And decide if I'm gonna put more money into my truck haha.

 

I just used a GPS and figured out how far off my speedo is. Roughly 10%. Once you know the offset, just memorize it.

I re-geared to 4.10 and it helped alot even with not-that-big tires, just unloads the motor a ton. Picked up 1 city and lost 2 highway with it. But a 4x4 will be stupid expensive to regear.