There probably will be a slight variance, but I wouldn't know how to calculate it. I had a similar situation with a Celica I used to own. The speedometer read several MPH higher than my actual speed. It didn't bother me much as the tires were far superior to the original ones of the specified size. The only way to know for certain is to try it. Also, don't forget that any variation will also affect your odometer reading. I found that to be more of an annoyance than the speedometer being off.