I just received mine today after upgrading from stock to 33s and I've reset my speedometer accordingly. I read the instructions and don't see whether or not I should do this, but do I also need to re-input my axle ratio? I didn't upgrade gears, so I'm thinking no, but wanted to verify before I put this thing away.

Btw, this thing is great. Very simple to use.

 

I couldn't see why that would be necessary but I will have the same questions tomorrow when I have to use my pro cal. Can you just out in the stock axle ratio just for shits and giggles?

 

What the Procal does is first reads your ECM and stores all the factory info in it. If you are just changing tire size all you need to do is reset the tire size, that's all. Gear ratio, tpms, and the few other thing you can change you can leave alone.

 

Just making sure, thanks!