# Lower profile tire in the rear? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** tires\ **Created:** [October 15, 2015, 9:19pm UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443 "2015-10-15T21:19:02Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Jersey\_Chris](https://avatars.discourse-cdn.com/v4/letter/j/dec6dc/32.png) [@Jersey\_Chris](https://community.cartalk.com/u/Jersey_Chris)\ **Post date:** [October 15, 2015, 9:19pm UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443/1 "2015-10-15T21:19:02Z")
A friend just picked up a 2010 Mercedes C300 from a used car dealer. I noticed that her car has 225/45 r17 in the front (proper recommended size for the car), but 225/40 r17 in the rear. What kind of problems would creep up because of this? I think she should return to the dealer and have them put the recommended tires all the way around. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [October 15, 2015, 9:29pm UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443/2 "2015-10-15T21:29:34Z")
The tire size in the rear should be 245/40R17. What is shown on the tire information label in the door jam? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [October 15, 2015, 9:59pm UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443/3 "2015-10-15T21:59:13Z")
Is it the AWD version? Then there could be damage to the AWD system. If RWD, the difference might set off the traction control/ABS improperly. Time to get all 4 tires the same size. ---
**Author:** ![ken\_green](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/ken_green/32/816_2.png) [@ken\_green](https://community.cartalk.com/u/ken_green)\ **Post date:** [October 15, 2015, 10:04pm UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443/4 "2015-10-15T22:04:44Z")
Look again at the rear tires to see if you may have mis read the 245. On many cars with different fron/rear, the objective is to have a wider rear, but not shorter ( closer to the ground ) If hers is the sport trim the fronts are in fact the 225/45r17 and the rears, like neveada said, are 245…245/40r17 IF hers actually has the 225 on the rear …it’s those that are wrong. BUT… if hers has the luxury trim then all four should be the 225/45r17. How to tell ? The rim bead WIDTH…ie; how wide are the rims ? The type with the different rears truly has wider wheels back there with the fronts being slightly narrower. The other has all four wheels the same , ergo, all four tires the same. ---
**Author:** ![Jersey\_Chris](https://avatars.discourse-cdn.com/v4/letter/j/dec6dc/32.png) [@Jersey\_Chris](https://community.cartalk.com/u/Jersey_Chris)\ **Post date:** [October 16, 2015, 12:15am UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443/5 "2015-10-16T00:15:04Z")
Great information, everyone. The best tip was to look at the information on the door pillar. (Thanks, Nevada-545). I’d never seen this before, but the front tires are supposed to be 225/45 and the rears are supposed to be 245/40. I misread the tire and thought both tires were 225s, but upon detailed inspection, they are correct. So I’ve made my friend stress out for no reason and I think I owe her a Coke. But we both learned something. Thanks, all! ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [October 16, 2015, 3:29am UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443/6 "2015-10-16T03:29:58Z")
Sounds like buying a new set of tires will involve shelling out some serious cash…But that’s one of the many joys of owning a Benz… ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [October 16, 2015, 5:24am UTC](https://community.cartalk.com/t/lower-profile-tire-in-the-rear/91443/7 "2015-10-16T05:24:14Z")
You were right to be concerned. Especially with newer cars with the high-tech suspension systems, it’s wise to stick with the exact tire size recommended by the manufacturer.