Alright, I need some clarification before I go ordering tires. :?:
tirerack.com says that 235/55/17 tires have a diameter of 27.3" and revs per mile of 759.
255/50/17 tires have a diameter of 27.1" and revs per mile of 769.
So if circumference is DIa. * Pi, we're looking at 80+ inches of travel for every rotation on the 255. So, an extra 10 revolutions per mile would mean that the speedo/odo would be off by 800+in./66+- feet per mile, no? Isn't this significant? That works out to 1 extra mile per 80 driven.
I guess that'* not much... but again how much is the speedo affected?

Please show me where I'm in error.
Thanks

0.2" will not force create a problem for you. 235/55/17 and 255/50/17 is generally considered equal.

Yea you will be fine with either size, but be sure to put the same size on both sides of the car. Don't replace just one. Also be sure when rotating tires that you move the 2 sets together if you just get 2.

If you go Tire Rack'* website, ther is a great deal of info on various tires. They also have a date base you can query that lets you see other peoples ratings regarding a specific tire in conjuction with their style of driving and type of car. I have found it very helpful.