So I'm at the jeep dealer and I was asking about recalibrating my computer to recognize my 33s (295/70/17) and they are charging me 120.00. My question is: Is this important to do or will it just be a waste of money? What exactly does it do when they recalebrate?

 

It tells the computer that you have a new tire height. Right now, your speed, distance and gas mileage will all be incorrect. If you have an Auto, your shift points will also be off. If you changed from a stock 32" to a 33", the difference will be minimal. If you went from a 29" to a 33", you should consider the calibration.

Just be aware that you would probably be better off with an aftermarket programmer or tuner, than paying that kind of money for the dealer to do it.

The AEV ProCal is programmer that has a lot of great functions in addition to recalibraing. I think they are running around $150.
The Superchips and Hypertech and Diablo are tuners. They are more expensive, but will also let you change the tunes for different fuels and conditions.

 

Is the AEV procal easy to use? Can anyone with a little sense do it?

 

Quick and easy. It is just a row of 2-position dipswitches. There is a big card telling you which positions to use for whatever option you want to change.

ex - first 3 up, next 3 down, next 2 up. Plug it into the port by your left knee, the horn will honk to let you know the computer was updated, turn the key off and remove the programmer.

The tuners will use computer updates, so you actually have to plug them in to your PC and download options and updates. Then you plug in to the port by your left knee and follow the screen prompts. More involved, but not hard.

 

Yup, it is easy to use. Good instructions and you can reset several functions in 15 minutes or less.

 

unless things have changed at the dealerships, you may want to verify they can reprogram or flash for 33's. It use to be dealer could only flash up to 32's. Someone please correct me if I'm wrong, but that's how it use to be.

 

I heard 32" was the largest they can do too, because that's the largest stock tire size.

 

That's true my dealers computer would only go up to 32.