Tire size with stock mags??

Hi there,

My 98 Malibu came with stock 215/60-15 tires. I was wondering if it would be okay to mount 235/60-15's instead. The diameter difference over the original is only 3.9%. Obvious concerns would be fender clearance (ie rubbing) etc.

Has anyone mounted these size tires on their Malibu? Any comments would be appreciated

Thanks.

Al

I'm not sure about the width issue, but you could lower the profile to 55 to get a closer tire diameter - less than 1/10th of 1% difference.

215/12.5*.60+15 = 25.32
235/12.5*.55+15 = 25.34

% error = |(25.32 - 25.34)| / 25.32 * 100% = 0.079%

Burly,

Couple of problems with your suggestion. To begin with 235/55-15 tires are hard to find. Tire Rack does not carry any brand in that size. Secondly I dont want to sacrafice comfort. Going to a 55 series tire will most definately compromise the ride quality.

While I won't argue the availability issues with the tire size, the ride comfort would not change by switching to a lower profile number because the overall profile Height would be identical. The profile is a percentage of width, 60 being 60% and 55 being 55% and so on. The measurement of the profile of the tire in inches is width/12.5*profile_percentage * 0.5. By increasing the width of your tire you are increasing part of the equation, so switching the profile_percentage by a similar amount will give you an actual profile in inches that is similar to the original amount. For example:

The profile in inches of the stock 215/60R15's is 215/12.5*0.60*0.5 = 5.16inches

The profile in inches of the suggested 235/55R15's is 235/12.5*0.55*0.5 = 5.17inches

The profile in inches of the 235/60-15's is 235/12.5*.60*0.5 = 5.64 inches.

So by maintaining the same profile percentage of 60, you are actually Increasing your profile. By moving to the 55 series you would be maintaining ride quality. By keeping the 60 series, you might increase ride compliance but at the expensive of handling.

BTW, Tirerack suggests 225/50R16's if you go with 16" rims for the 2003 Malibu. While the stock wheels are 15", if they are suggesting 225's for 16" wheels then theoretically (meaning as long as they are correct) the width should fit without rubbing. However with the 17" wheels they are still recommending the 225's, but with a lower profile percentage, 225/45R17. My guess is that 225 is the largest that will fit in the wheel wells without clearance issues.

Hi Burly,

That makes perfect sense. I should have thought of that

Thanks.

Al


BTW, Tirerack suggests 225/50R16's if you go with 16" rims for the 2003 Malibu. While the stock wheels are 15", if they are suggesting 225's for 16" wheels then theoretically (meaning as long as they are correct) the width should fit without rubbing. However with the 17" wheels they are still recommending the 225's, but with a lower profile percentage, 225/45R17. My guess is that 225 is the largest that will fit in the wheel wells without clearance issues.

Every malibu I've ever seen come in to the shop, including mine, has the center of the tread smoked out of the tires. It's not due to over inflation because they call for 29F/26R psi so my best guess would be that the stock 215's are already too wide for the stock 6.5" wheels. I upgraded to 225/40/18 and havent had a problem with uneven wear since. BTW the rims are 18x8" which probably helps to spread out the load more evenly. I use 205/65/15 Michelin Arctics in the snow and they wear great too. They're a bit taller but I didn't notice on the speedo.

Yes DaYtOnAt2,

What you stated makes perfect sense. The center of my tires have worn much faster than the rest of the tire. Instead of going to a 225 I may just go with a 205.

Thanks for the post.

Glad I could help.