I've been reading about people who say their MPG went down noticably after intalling 18's. I assume they weigh the same so I attribute this to high rolling resistance if this is true.

Anyone care to opine?

 

dunno but mine dropped a few mpg......

 

well, bigger wheels need more energy to get them rolling and more energy to stop them. inertia and momentum the double edged sword!

also the weight of 18s can (but not necessarily) be more than 17s, it depends on what they are made of and how much rim there actually is. the lighter in weight the rim is the better it is on your mpg.

 

^^^ Yeah, what he said.

 

There are already a couple of lengthy threads on theis. Check Tread and Butter.