I bought a '05 1500 2 weeks ago from a local dealer. Today I went to a dealer closer to look for bed rails and asked if there was a way to get the spec sheet for the original equipment installed on my truck. I noticed I was supposed to have 20" rims. Much to my surprise I have 17" on there. My speed, mileage and all associated are of by about 10%. Is there a way to have the speedo, etc calibrated for this or am I going to have to spend a bunch on tires and rims? Thanks in advance, Joe.

The dealer should be able to recalibrate everything.