Leeb9

I have a 2016 S550 4matic with the 19” wheels with sport package.
The tires are 19" 245/45R19 front and 275/40R19 rear. I was going to buy non run flat Michelin (only tires my wife wants on her car) pilot Sport All Season 4, which have great reviews.
The issue is
front tires 245/45ZR19. Overall diameter 28”

Rear tires 275/40ZR19. Overall diameter 27.6”

is this within acceptable specs or will the 4matic have issues or damage?

Thank you

DaveW68

That is perfectly fine.

Mitch Alsup

Take the numbers (x, y, and z) from the tire specification:: x / y ZR z
x = 245mm
y = 45%
z = 19"

Rolling diameter is::
Rd = ( x * y * 2 ) / 25.4 + z

Rd = (245 * 0.45 * 2 ) / 25.4 + 19"
Rd = 27.68"

Works for any tire. BTW 25.4 converts millimeters into inches.

Leeb9

Thank you all.

Tirerack specs state the rear tire revolutions is 751 per mile vs. 747 for the front due to the different diameters.
Front and rear diameters matched exactly on the previous tires.
Just wanted to make sure the 1.5% diameter difference will not cause transfer case or transmission issues down the road.

Barry Hanna

https://www.calculator.net/tire-size-calculator.html

Use this to do easy comparisons of sizes, etc.