Date: Sat, 17 Jun 2006 00:27:48 GMT From: - Bob - <uctraingnospamanet.com> Subject: Re: Changing tire size on a 9.5
On 15 Jun 2006 11:55:42 -0700, "Paul" <penjr1nospaml.com> wrote: >i've heard of people putting tires as large as 215/40 17's on a saab >with few rubbing problems.i am about to put 205/40 17's on my saab >NG900SE. from people i've talked to, these are the largest that safely >fit with no rubbing. That's not much sidewall and a fairly large diameter change. I hope you drive on smooth roads. >be warned that your new 8 inch tires will be much more prone to >hydroplaning than your old ones. there will be a distinct cornering >benefit, as will your traction in general, especially braking. if you >do a lot of bad-weather driving, be cautious with this change. A 215 is only 5mm wider on each side than a 205. Even a 225 is only 100 wider. Not that drastic. The first common misconception is that there is some cornering benefit associated with wider tires. It's not true. The benefit comes from increasing the wheel size and causing a concurrent decrease in sidewall height. The lower sidewall increases stiffness and cornering response (or more accurately, reduces loss of response from sidewall bending). Another common misconception is that a wider tire increases traction. It does not. The same amount of rubber is in contact with the road with a wide tire as with a narrow tire. The increase in handling (not traction) comes from what I mentioned above. There may be some advantages to a wider wheelbase in stability but at the same time, you are loading your suspension differently than designed and it may not help in any or all areas.