OK search and google have not really gotten me any where. I am currently running 215/40/17's on my R53 with M7 springs. I am thinking about going to 215/45/17's but I can't find anything that tells me how much bigger the 45 is compaired to the 40 (physically).

I would like the extra cusion in the hopes I'll go through less front strut mounts BUT I don't want to deal with rub when I get the alignment set. Are the 45's REALLY that much larger?

Here is how it's sitting now:


.


What does the community think?

 

There is slight variation brand-to-brand, but you can't be guaranteed of the no rub with 215/45, with passengers in the car and bouncy roads. I think you will be largely ok, and rubbing will be rubber-on-plastic (rubber generally wins, so no tire damage), so go for it! a little more cushion will be worth the risk of that occasional embarrassing scraping sound.

 

try this
http://www.1010tires.com/TireSizeCal...bmit&reset=yes

 

BraVO sir!!!! Thats what I was looking for. About .4 of an inch more in the radius. I don't see that it will be an issue.

 

Just in case you didn't know this, tirerack.com has the specs of all of the tires that they carry listed under the specs tab on any particular model of tire. If you click on that tab, you will be able to see the difference in spec of any size of tire. Always a helpful tool imho

 

OldGameFreak: Here's more data to ease your mind. While the 215/45/17 size is .8" larger in diameter than your current 215/40/17 size, it's only .3" larger in diameter than the OE size 205/45/17.

 

Tire brand can make a big difference unfortunately. I went from a Michelin 215/45/17 to a Goodyear 215/45/17 and there is now a lot more rubbing on my lowered R55.

Most of the abuse is taken by the plastic, but the tire shows sings wear and peeling. Obviously not going to damage the tire.