Originally Posted by skylineguv
With a larger than stock tire, your speedo will read slower than actual speed.
That having been said, as long as you remember about the speedo difference, it doesn't hurt to add a little extra sidewall for the winter months. I've settled for 235/40/18's on both cars, which is a nice compromise if you run either a square wheel setup, or factory staggered.
ah - thanks for the clarification. Couldn't remember if it was faster or slower.