The OEM tires are 235/45/18 and 26.3" in diameter. The 135/80/18s are 26.5" in diameter, 0.8% larger.
A 145/80/18 is 27.1" in diameter, 3% larger. Within 1% is ideal. 3% may throw alot of errors.
My original post should have said "alloy" wheel, not allow wheel! D'oh!