There are two things to consider. Do you care just about how the tires look or do you want them to perform as the manufacturer intended? Look at the specs from any manufacturer and they all suggest no wider than a 255 on a 17x8 in rim. Even Nitto which most will agree run narrower than most still suggest no wider than a 255 for a 17x8. If all you care about is how it looks, yes you can squeeze a 275 on a 17x8 in rim but, the tire will NOT perform as well as it would on a 17x9 as it was intended. Go to any manufacturer's website and take a look at the specs, they are there. Here are just a few including Kuhmo.