I recently replaced my 235/45 R 17 94 H Continetals with Yokohama 225/50R17 94V on all 4 corners. I had a pothole mishap and Discount Tire talked me into 4 new since the rears were getting close to being worn anyway.

I've looked up the Rev's per mile and compared them between the two tires. The Continentals turned at 824 Rev's per mile and the new tires turn at 797 Rev's per mile.

Is there a way to recalibrate the ECU for the tire Diameter change?

I'm pissed off because the guy at Discount Tire told me that they were the same overall diameter as the Continental's. Of course I find out that they are not after I've already driven off.

Any suggestions?

 

The difference is only 3.3%. I would check your new readings against a series of mile markers. You might be indicating something closer to actual speed now. It could go either way.