Procal needed for BFG ko2's?
 

Just got my new 2017 2 door Sahara. Had the dealer put on the lift and 285/70/17 BFG ko2's on pro comp Rockwell wheels. The ko2's are 32.7" and the dealer said the were close enough to the stock 32" Sahara tires as to not need to be adjusted with a procal. I had the procal in my budget and am okay with spending the $170 if its needed. If not can apply that money elsewhere. So, should I do it or not?

I spent the $170 but I really don't think it makes any difference. I have the same tires with 17 x 9 wheels. If I ever go to a larger tire, then yes the Procal will come in handy. By the way, these K02s are awesome looking tires and are super quiet. If I go bigger in the future, I'll go with K02s again.

6-speed no need, auto maybe, depends how the tranny takes it. Drive and see how the shift points are

I think the shift points are a little high. It's an auto. If that will make a diff.

Download a speed app on your phone and compare to see how much the speedometer is off.

I would get one. Yes it will make a subtle difference with 285/70-17 tires. But even more important is you can set your psi threshold down from 37 or what ever it is to 28psi so you can run 32psi without your nanny light coming on. Oh and trust me you will be going bigger in the future it is a fact of life when you start down that path.

From 32" to 32.7" you would be wasting $170.

That's one point...but the Super chips Flashcal also serves as a code reader, can change a whole lot of Factory presets like DRL or lane change features and can also serve as an engine idle boost if you would add a winch later on. Plus it can be later upgraded with tuner software. Seemed worth it to me....but I installed 35's...😎

Going to check the speedo today. This is my DD on socal freeways. Don't want to be going faster then it says. Sure to get a ticket eventually that way. More concerned about the shift points, will see how it handles the hills on the 15 fwy tomorrow and decide.

I say speed check it. You've assumed the original tires are, in fact, 32"... I'm betting they were something less than that when measured. You're also using the dismounted size of that KO2 (32.7"), it's likely less than that.

In the end, probably negligible but nice to know.