Thanks for the reply, and no, left the old rims and tires. Had a chart with the comparisons and, yes, figured they wouldn't have made such a drastic change but it is tghere. Can leave a stop ligh and the speedo doesn't even move till at least 15 mph, reading my gps. speed.. All started after the tire/rim change. Thought the driveshaft, fly wheel and rear end rotation, after the disconnect of the battery and then letting the "wave length being read by the speed sensor would pass all the new info to the ecu and letting the computer make all the new adjustments, never believed it wouldn't catch up. Even the newly installed sensor didn't change a thing. Coincidence??? Not a big believer. There are no changes in transmission shifting, stalling or anything else associated with a bad sensor. Thanks again but maybe another member has a different idea. If I didn't have that real time gps built in, probably would no longer have a driver's license.LOL