Hey guys. Need some help setting up the Superchips and tire size. I see everyone on the forum recommends measuring the auctual tire size. I am running 305/70/r16 KM2's and I have about half tread life left. They are measuring in at about 32 inches (I have a full size spare that looks to measure in at 33") and I am running the 87 octane tune. No doors and no top right now since it's summer (it never rains here) and about 28-30psi.

Anyone else running this tire size in a KM2? I just want to make sure that my spedo is as accurate as possible. It seems like I am going much faster than I used to when I'm on the freeway. Any suggestions? Thanks in advance.

 

Check you speed w/ a gps,nuvi or garmin.

 

If your tires are measuring at 32" than it shouldn't be off or even that noticable if it is off. The stock BFG's are 32" so the computer/speedo should be reading pretty close on accuracy...

 

I agree. Borrow a GPS and check it. You will have to program it a couple times to get it perfect.

 

Ok I am going to have to track someone down who has the Nav unit or find a street sign radar. Superchips has it programmed at 31.75 right now so I am going to change it to 32 even. With the 87 tune it is shifting faster and also seems like it is just driving faster. Maybe I'm just not used to the extra power since I have the doors and top off also. The weight is down and I just installed Superchips. I wish it drove like this all the time. I'll keep you guys updated when I get the unit or find a sign.

Any other tips with Superchips are welcome. I have turned my TMPS sensors off because even if I put them all the way down to 26psi (which, why is that the lowest #, why not like 20psi). Does that mean maybe when the shop installed my tires and wheels that they incorrectly installed one of the sensors? Or one could have went bad I guess? Thanks for the input.

 

ok guys I got it all figured out. Somehow I didn't save the changes when I ran the 87 tune so it reverted me back to stock tire size. Stock tire size was 30" and it needed to be programmed in as 32". It made a big difference. Checked it at a speed sign in the neighborhood and it is within 2mph each time. That's good enough for me and I am sure there is a small margin of error with this anyway.

87 tune works great. I shut the TMPS sensors off completely and made sure the tire size and gear ratio were set correctly. Loving the superchips. Thanks for the help.