[paradocs98]

Thanks to forum member Tag who posted the online version of the M2C manual, I’ve been dong some reading while waiting for my car to arrive in a couple of months. I noticed that BMW’s recommended wheel lug bolt torque is now 140 Nm (101 lbs-ft). For as long as I can remember, BMW’s recommended lug torque setting has been 120 Nm (88.5 lbs-ft). Not sure when BMW changed this value, but I’m glad I noticed it. Heads up for anyone who’s had past BMWs like me and assumed 120 Nm was still correct.

[wanofakind01]

Yeh changed a couple years back, had the same reaction as you

[dcmac]

So is this just for the M2C?

I run Apex and OEM rims for my OG M2 and always torque to 88... on the advice of many people more experienced than me!

[nioh_lbbm2]

RTFM guys

[CosmosMpower]

I've been doing 100 for years

[eeyang92]

Originally Posted by dcmac

So is this just for the M2C?

I run Apex and OEM rims for my OG M2 and always torque to 88... on the advice of many people more experienced than me!

Nope, 101 lb-ft.

[tux2005]

My understanding was that when BMW switched to M14x1.25mm threaded lugs that the torque spec changed. With my 2014 228i the spec was 103lbs/ft (unfortunately not printed in the manual, I think it was in service manuals), my 2017 M2 states 101lbs/ft in the manual. I think all F-series use the M14x1.25mm thread while E-series use M12x1.5mm (exception apparently being E70 X5, they use M14x1.25mm).

The M12x1.5mm has a lower spec, I've worked on a 2000 E39 which is 88lbs/ft and a 1998 E36 which specifies 74 lbs/ft (!!! this seems really low to me so I have usually gone a little higher at 78lbs/ft).

The proper torque spec is going to depend on the thread and materials, with the M14x1.25mm I think you probably want to stay in the 100-105lbs/ft range while M12x1.5mm is 80-90lbs/ft.

[KevM2]

I've never torqued a lug nut in my life! Always gone by feel. Why is a number different by a few Nm so important?

[chris719]

Judging by the number of shops that tighten them to 9999 ft-lb with an impact gun, I’d say you’re fine exceeding 100 as long as you can get them off and you’ve tightened them in a star pattern and equally. I tighten mine 10% over the spec because my wrench is cheap and rather be a little over than under.

They probably won’t fall off at 80 either, who knows why they changed the spec slightly.

[paradocs98]

Originally Posted by tux2005

My understanding was that when BMW switched to M14x1.25mm threaded lugs that the torque spec changed. With my 2014 228i the spec was 103lbs/ft (unfortunately not printed in the manual, I think it was in service manuals), my 2017 M2 states 101lbs/ft in the manual. I think all F-series use the M14x1.25mm thread while E-series use M12x1.5mm (exception apparently being E70 X5, they use M14x1.25mm).

The M12x1.5mm has a lower spec, I've worked on a 2000 E39 which is 88lbs/ft and a 1998 E36 which specifies 74 lbs/ft (!!! this seems really low to me so I have usually gone a little higher at 78lbs/ft).

The proper torque spec is going to depend on the thread and materials, with the M14x1.25mm I think you probably want to stay in the 100-105lbs/ft range while M12x1.5mm is 80-90lbs/ft.

This is really interesting--good info; makes sense.

Originally Posted by KevM2

I've never torqued a lug nut in my life! Always gone by feel. Why is a number different by a few Nm so important?

Originally Posted by chris719

Judging by the number of shops that tighten them to 9999 ft-lb with an impact gun, I’d say you’re fine exceeding 100 as long as you can get them off and you’ve tightened them in a star pattern and equally. I tighten mine 10% over the spec because my wrench is cheap and rather be a little over than under.

They probably won’t fall off at 80 either, who knows why they changed the spec slightly.

This drives me nuts. I trust shops to know more than I do when it comes to this stuff. It's what they do. I pay them to be the experts and do the right thing. And yet they routinely overtighten or undertighten lugs after doing wheel or brake service. Dealers and independent shops included. I've come home from the dealer with four bolts on one wheel impacted down way too tight, and the fifth bolt on that wheel not even finger tight to the hub. I would try not to worry about it, but lug torque values are set for a reason--if they're too loose, they will move more and more over time and eventually allow wheel movement on the hub, potentially causing a wheel to come off at speed. If they're way too tight, they will stretch the threads, also leading to failure.

Same with tire pressures. I brought my OEM Audi S3 wheels to Mavis Tire the other day to have the winter tires switched back to the stock PZeros in preparation for lease end. When I got home I confirmed pressures before sticking them in the garage. Three tires were at 40ish psi (fine) and one was at 75 psi. You can't make this stuff up.

[Franzino]

Originally Posted by paradocs98

Thanks to forum member Tag who posted the online version of the M2C manual, I’ve been dong some reading while waiting for my car to arrive in a couple of months. I noticed that BMW’s recommended wheel lug bolt torque is now 140 Nm (101 lbs-ft). For as long as I can remember, BMW’s recommended lug torque setting has been 120 Nm (88.5 lbs-ft). Not sure when BMW changed this value, but I’m glad I noticed it. Heads up for anyone who’s had past BMWs like me and assumed 120 Nm was still correct.

On my Z4M and my other BMW's I used 120Nm. On my M2 they advised me to use 130Nm....been using this for two year, 6 trackdays and total of 60.000km driving. Never heard about 140Nm.

[Tano]

Originally Posted by Franzino

On my Z4M and my other BMW's I used 120Nm. On my M2 they advised me to use 130Nm....been using this for two year, 6 trackdays and total of 60.000km driving. Never heard about 140Nm.

See for yourself in the factory instructions.

[Franzino]

Originally Posted by Tano

See for yourself in the factory instructions.

Thanks

[NEfan508]

Sun Motors in PA recommended 120 nm, they just did this last week on another M2C with the same winter wheel setup 641m staggered setup

They disregard the 140?!?
Maybe the 140 is for the stock wheels?

Confusing

[nioh_lbbm2]

Originally Posted by NEfan508

Sun Motors in PA recommended 120 nm, they just did this last week on another M2C with the same winter wheel setup 641m staggered setup

They disregard the 140?!?
Maybe the 140 is for the stock wheels?

Confusing

More likely they made a mistake. Take into account they have to support lots of different BMW models from many different generations. Mistakes can happen. Can't refute solid text in a manual

[NEfan508]

Originally Posted by nioh_lbbm2

More likely they made a mistake. Take into account they have to support lots of different BMW models from many different generations. Mistakes can happen. Can't refute solid text in a manual

Just called another bmw store, they confirm 140 nm
another store "what ever you want man" lol, seems not to matter much AND these are Bmw service advisor(s) tight'ish is fine ?!?

Btw, never had any vehicle that I needed the lugs torqued to spec until now

or ever cared to confirm the spec on

Edit: simple answer I'm going with 140 nm on my 19 m2

[Caduceus]

Several of you have noted it already but it's to do with the diameter of the wheel bolts. Bigger diameter = more torque required. Hence the change from M12 to M14 bolts has lead BMW to a revise their torque specification from 120Nm to 140Nm.

140Nm is actually on the conservative side for what a grade 10.9, M14 bolt is designed to handle. As usual, all this stuff can be found with a quick web search.

[IMG][/IMG]

Realistically, the correct answer is "tight enough not to come undone but not too tight to strip the threads". But being German, they like specifics. Therefore 140Nm it is.

[nioh_lbbm2]

Originally Posted by Caduceus

Realistically, the correct answer is "tight enough not to come undone but not too tight to strip the threads". But being German, they like specifics. Therefore 140Nm it is.

Being German, the correct torque value is actually Gutentight

[nearwater4me]

Those with wheel locks from the dealer, check them if they’re torqued properly.
I noticed all 4 of mine were hand-tightened at best.
Came loose with minimal amount of force.
I re-torqued every bolts to 101 lbs/ft

[CTSean]

Originally Posted by nearwater4me

Those with wheel locks from the dealer, check them if they’re torqued properly.
I noticed all 4 of mine were hand-tightened at best.
Came loose with minimal amount of force.
I re-torqued every bolts to 101 lbs/ft

It's an incredibly picky thing, but 140Nm = 103 ft-lb

https://www.metric-conversions.org/e...oot-pounds.htm

[nearwater4me]

Thanks for the correction.
I’m not too worried about it as I tend to go slightly more after the ‘click’

[paradocs98]

Originally Posted by Caduceus

Several of you have noted it already but it's to do with the diameter of the wheel bolts. Bigger diameter = more torque required. Hence the change from M12 to M14 bolts has lead BMW to a revise their torque specification from 120Nm to 140Nm.

140Nm is actually on the conservative side for what a grade 10.9, M14 bolt is designed to handle. As usual, all this stuff can be found with a quick web search.

[IMG][/IMG]

Realistically, the correct answer is "tight enough not to come undone but not too tight to strip the threads". But being German, they like specifics. Therefore 140Nm it is.

This is great. Thanks for posting.