[ERDRFF]

I have the 21" rims with 315 width tires out back. My sister has a GLE43 AMG also with 21" rims and 315 out back. Yet her tires appear wider and fat. My G05 rear tires appear narrow. Is it because of the profile of the tires or the tires brand itself?

[Auricom]

Originally Posted by ERDRFF

I have the 21" rims with 315 width tires out back. My sister has a GLE43 AMG also with 21" rims and 315 out back. Yet her tires appear wider and fat. My G05 rear tires appear narrow. Is it because of the profile of the tires or the tires brand itself?

Did you measure the width and compare the two? That would be more conclusive than saying it "appears wider and fatter"

I swear my arse looks fatter in this pair of jeans and slimmer in another pair...

Tread width can vary between tire models. Tread pattern can also create an optical illusion that makes it appear wider. Without knowing the tire model on yours and your sister's GLE AMG, going to find it difficult to provide a conclusive answer.

[ERDRFF]

My sister's GLE43 has the Continental tires at 315/40 R21 and my BMW has 315/35 R21 Pirelli tires. I attached a picture but I'll have to get a better pic next time I see her.

[bichoo]

Originally Posted by ERDRFF

My sister's GLE43 has the Continental tires at 315/40 R21 and my BMW has 315/35 R21 Pirelli tires. I attached a picture but I'll have to get a better pic next time I see her.

As Auricom mentioned, the thread width can vary tire to tire.
I would go ahead and measure them, I bet you they are very similar in width, optical illusion!

[ScottMZ3]

I went out an very unscientificly measured the width of the rear tire. The X5’s 315 Pirelli tire does in fact seem to be a bit undersized! Below is the X5 315 tire and my ZL1’s 305. The 305 is a fair amount wider! WTH?

I think he Pirelli side wall is just more rounded where as ZL1s Michelin are more square. So the 315 size must take into account the width all the way to the rounded side wall outer edge?

[Jrunr]

The contact patches do look a little different... could that also be due to the Perelli being a RF tire??

[AndroidRobot]

I hope we get more tire options I'd love to run some Michelins preferably the Pilot Sport AS 3+ but I'd rather not go outside of factory spec

315 tires are 12.4in wide

[roadkillrob]

I have found the Michelin’s tend to be on the wider side with more square shoulders with the tread going right to the edge it seems to vary a lot between brands

[******]

The wheel size can vary, even with the same size tires... that might account for the look. My f15 used the same width tire as my g05 but the wheel was wider on the f15.

[Ilyam5]

what is the rim width? same tire will look different on dif rims.

275 tire can seat on rim from 8.5-10.5. It will make the tire look stretched or bulged

[ERDRFF]

I too measured the tires from sidewall to sidewall and both are 315 mm but the BMW tire is just a shade narrower. However, the contact patch of the BMW is noticeably less meaning the BMW tire has more bulging sidewalks whereas the Benz has more upright and straight sidewalls. Weird considering BMW uses run flats.

[ScottMZ3]

The ZL1 and the X5 both have 10.5” wide rear wheels (although the ZL1 wheels are 20” not 21”). So it must just be the tire brand that makes the difference. Because the contact patch is clearly very different. Maybe PS4S tires on the G05 X5 would look more like the F15 X5...too bad the tire options are so limited.

[absolut257]

Tire differences aside, GLE43 rear wheels are 11" while the X5's are 10.5. That 1/2" tends to stretch the tire a bit more.