2006 Duramax 2500HD - U7186 from 2006(not updated)

[LarryA]

In order to correct speedometer - should I be using tire size or height (32 inches)? I just added cold air intake and 4" exhaust (no cat) , should I see better fuel mileage? With these changes should I update my predator or stay with the old?

[mikel]

Either way is fine, they both do the same thing.

[Trotorx2]

I haven't had much luck in adjusting the speedo with the predator. My speedometer is always slower that I'm actually going. Best I had it was 2mph then I put 17's on and it is back to 4-5 mph slow also if I get the speedo close to correct it sets off the ABS light.

[LarryA]

I changed my tire size to the measured inches and my speedo has changed from 3 mph over to around 1 over.
Mikel - can you answer both of the other questions I asked. Thanks

[mikel]

Id update the Predator for sure, it has some new features.