I just thought I would share what I found while setting my tire height and correcting with the aev procal. The instructions state to set the height on the module to the actual tire height measured on the tire. I found an issue with this. The center to the ground is less than the center to the top of the tire. When I entered the overall measured height, it was fine at low speeds, around 35mph and under however was fast by nearly 4 mph at highway speed. I remeasured the center of hub to ground, doubled that and entered that value in to aev procal module and the correction is spot on.

I hope this helps anyone who has had the same findings.

 

Great info as I'll be ordering mine soon and will remember how to do it right now.

 

Maybe I'm dumb... But can you give me a better perspective, measurement wise. I have 35 12.5 17. They measure 34 and some Change.

 

Just measure actual tire height. Forget the manufacturers measurements.

 

Yes, i used it to program mine. I also redo it every 10k as the tires get smaller. I run 37s

 

You should be measuring the actual height of the tire. Lay a level perpendicular to the top of the tire and measure the distance from the bottom of the level to the ground. Do this with all four tires at normal PSI to get an average. Then you can test your speedometer with a GPS to see how accurate you are.

 

I had to take off the .2 today. Speedo only reads 1mph high all speeds. I can live with that.
BTW, I set my turn signals to DRL, it worked one time, now nothing will program as a DRL. Any ideas guys?

 

just in case you did not know the drl only come on when put into drive. If you are in park they are not on when programmed with the aev. If that is not the problem try setting everything back to original stock settings and then reprogram

 

I have a manual, but will check for operation next drive. Thanks

 

Here is another way to get the tire diameter measurement the computer wants to see:

Stick a piece of chalk in the tire tread.
Move the Jeep until it makes two chalk marks on the pavement.
Measure the distance between the marks.
Divide by 3.1416.
From that number, the computer will know exactly how far the Jeep moves with one revolution of the tire.