Jayhawk

Just had summer tires put back on and your installer wasn't sure how much torque to put on the lugs. One guy said 80 and another one said 110. I think they used 85 lbs., but would like to know what you would advise for my situation?

My situation:
18x8.5 AMG Double Spoke Bright Sil
18x9 AMG Double Spoke Bright Sil
245/45WR-18 Goodyear Eagle F1 GS-D3 XL
275/40YR-18 Goodyear Eagle F1 GS-D3

(Standard lug bolts for my S-class.)

velvet fog

Your manual should say. Off the top of my head I think 85 is more correct. 110 definitely not. I seem to remember 75 last time I rotated the tires on my CLK.

Jayhawk

That's what I thought too, but the Operator's Manual says "It is imperative that ..." they be tightened "to 110 ft. lbs. of torque." But they are talking about the OEM, 16" wheels. I don't know if it is different for the 18" wheels or not. I am hoping Luke will be able to settle this before my wheels fall off.

Jayhawk

OK: I just got an email from the top tech at my dealer's service dept. and he said 110 is standard for all S-class cars!

srknutson

110 is correct!

Luke@tirerack

Hardware Size / Torque in Ft/Lbs

10MM / 45-55
12MM / 70-80
14MM / 85-90
7/16" / 70-80
1/2" / 75-85
9/16" / 135-145

Size of Bolt or Stud / Mininum Number of Turns

14x1.5mm / 7.5
12x1.5mm / 6.5
12x1.25mm / 8
1/2" / 8
9/16" / 8

NOTE: Since the thickness of an alloy wheel can differ from Original Equipment wheels, also verify that the threads will be engaged by the lug nuts or bolts. Refer to the chart (above) to determine the number of turns or the depth of engagement typical for your stud or bolt size.

Jayhawk

Thanks Luke! I saw this on your site but was/am not sure how to apply it to my situation. My owner's manual says "it is imperative that the lugs are tightened to 110..." and my MB service tech said 110 too, so I had them re-torqued to 110 and the car rides and handles noticably better now. From what you say, however, I guess there is more to it than just following the manual.

You don't usually re-reply to threads, but how would your formulae about apply to my S-class w/ your AMG wheels? Would it result in 110 too, or do I still have it wrong?

Here is what you sold me:

225/60QR-16 Michelin X-Ice
18x8.5 AMG Double Spoke Bright Sil
18x9 AMG Double Spoke Bright Sil
245/45WR-18 Goodyear Eagle F1 GS-D3 XL
275/40YR-18 Goodyear Eagle F1 GS-D3

RobertG

If you dont change the size of fasteners then the torque will stay the same , unless you change the rims to a different material like aluminum to steel or vice versa.

Jayhawk

Thanks!

I use the same lug bolts, but am not sure if the wheels are the same material--though I suspect they are, w/ the OEMs and the AMGs.

When I look at that table of Luke's though I can't imagine that it would ever come up to 110 ft.lbs. so would still like to see what Luke says.

meanie

The 110 is probably Nm ( Newton meters ), which is 81 ft/lbs .

Jayhawk

Here is the exact quote from my Operator's Manual: "It is imperative that the wheel mounting bolts be fastened to a tightening torque of 110 ft.lb. (150 Nm) whenever wheels are mounted."