My dealer technican tells me he can't use Trech 24 to reprogram speedo for 265 tires because that size isn't in the system. Is tbis true? If not, whats the secret to using th Tech 24.

Bill, I wouldn't even worry about it. Going from 245's to 265's doesn't throw it off very much. IIRC its within 2-3 mph low at 60 mph.

Tom

If you know anyone with a GPS you may check your speed before you do anything else.

When I went from 245s to 265s My speedo actually got closer to correct than it was from the factory. From the factory it was almost 2mph off. After I installed the 265s it now reads within 1/2mph at all speeds up to 80.