petrolv said:
- In most places 15" tires are cheaper (although not all),
- a 15" has more sidewall to allow for more tire flex (great offroad),
- a 16" will ride better on the road (handling wise) compared to an equivalent size of 15",
- with a 15" tire you have more rubber to balance compared to more wheel to balance with a 16". Wheels aren't perfectly balanced from the factory either.