Bill, The rear tire does not affect the speedo. Since the speedo is controlled by the angle drive on the front wheel, it's diameter is the only one that matters. I've got the Yokos also, and we did some testing with my Dad's truck and my wife's car using two-way radios, and the speedo in our D with the Yokos was quite accurate. You may want to try this before you embark on any speedo recalibrations. Mark N VIN 6820 At 09:51 PM 9/30/00 EDT, billschaferabn@xxxx wrote: > > After putting on my new Yoko AVS tires I noticed that it seemed my >speedomter was registering faster speeds than my previous tires. I know the >tires on the rear (235/60VR-15) were quite a bit larger in tire height than >my old ones. The 195/60R-14 front tires are close to what I had on before. My >question is would the larger rear tires cause my speedometer reading to be >off? Do I need to calibrate the speedometer? Thanks > >Bill (11096)