Why 666M on GTS?

[Kabrich]

Originally Posted by SROC3

Didn't the GTS do the 2nd fastest time around the Nurburgring on these wheels?

Not unless it blew away the Porsche and McLaren.

[Brasko]

Originally Posted by CanAutM3

A few data points on dimensions and weights:

• GTS 666M - 19X9.5 24.0lb / 20X10.5 28.4lb
• ZCP 666M - 20X9.0 25.3lb / 20X10.0 27.1lb
• STD 437M - 19X9.0 22.9lb / 19X10.0 24.2lb

When you consider that the front GTS wheel is 0.5 wider than the 437M, the 1.1lb weight penalty is not that bad. Maybe they made the 666M very sturdy.

But I still find the 666M wheels quite heavy compared to the 437M though. I had much higher expectation when BMW advertised the 666M to be "weight optimized" .

Based on those numbers there really isn't a difference between ZCP & GTS wheels. Yes, the GTS has 19's in the front. However, the 1.3lbs weight difference is added back on the rear with the wider wheels. There is no real weight savings between the ZCP & GTS wheels. The combined weight of all 4 wheels add up to the same 104.8lbs.

[Pennzoil]

There is the weight comparison

[Fake News 2017]

Because 666m wheel OWNS!!! Like it and like liking it!!!

[Jim B]

Of course, you guys could lighten up your wheels by filling your tires with helium instead if air.

[Alpinef82]

They should have made a carbon center lock wheel

[sdshah]

Originally Posted by Kabrich

Not unless it blew away the Porsche and McLaren.

Or a 50k Camaro....

[Agamemnon]

Originally Posted by Jim B

Of course, you guys could lighten up your wheels by filling your tires with helium instead if air.

Or hot air. A lot of us on this forum are full of it.

[1uscalumni]

Originally Posted by CanAutM3

A few data points on dimensions and weights:

• GTS 681M - 19X9.5 20.4lb / 20X10.5 24.2lb
• GTS 666M - 19X9.5 24.0lb / 20X10.5 28.4lb
• ZCP 666M - 20X9.0 25.3lb / 20X10.0 27.1lb
• STD 437M - 19X9.0 22.9lb / 19X10.0 24.2lb

When you consider that the front GTS wheel is 0.5 wider than the 437M, the 1.1lb weight penalty is not that bad. Maybe they made the 666M very sturdy.

But I still find the 666M wheels quite heavy compared to the 437M though. I had much higher expectation when BMW advertised the 666M to be "weight optimized" .

I learn a lot from your posts thank you

[Colinv6]

Holy thread bump. Question for the wheel gurus. Would the wider 666M front and rear with 265/285 cup2 as per GTS specs, with offset 29 front and 42 rear cause any rubbing on the struts?

They obviously clear the GTS which had Coilovers but with normal comp suspension and MPHAS, it goes approx 6mm further inwards and outwards due to the wider rim.

[TractionControlDelete]

Originally Posted by Colinv6

Holy thread bump. Question for the wheel gurus. Would the wider 666M front and rear with 265/285 cup2 as per GTS specs, with offset 29 front and 42 rear cause any rubbing on the struts?

They obviously clear the GTS which had Coilovers but with normal comp suspension and MPHAS, it goes approx 6mm further inwards and outwards due to the wider rim.

Keep in mind that the GTS has a different knuckle so clearance will be different compared to the regular car

[Colinv6]

Originally Posted by TractionControlDelete

Keep in mind that the GTS has a difference knuckle so clearance will be different compared to the regular car

Thanks! I’m sure they probably would fit on, I was planing to order the Orbit grey ones from the DTM edition but it’s an expensive gamble if they don’t fit and would be a hard resale.

I think I’ll stick to 763M in the end, there’s probably a reason it’s not been done (can’t find any regular M4’s with GTS wheels online)

[ENDL3SS]

I have a set of GTS wheels on my F80 with MPHAS. No fitment issues.

[Colinv6]

Originally Posted by ENDL3SS

I have a set of GTS wheels on my F80 with MPHAS. No fitment issues.

Nice!! Do you have any pictures?

[ENDL3SS]

Originally Posted by Colinv6

Nice!! Do you have any pictures?

Here you go!

[Colinv6]

Originally Posted by ENDL3SS

Here you go!

Thank you!! Looks great. So no rubbing at all and are you using spacers?


Lastly.. these or 763’s?! I’ve been debating on wheels for weeks now

[jaylazy2020]

Originally Posted by Colinv6

Thank you!! Looks great. So no rubbing at all and are you using spacers?


Lastly.. these or 763’s?! I’ve been debating on wheels for weeks now

I just got a set of 763m and I loved the 666 so much initially I wasn’t sure but now I’m lovin the 763 and so easy to clean

[ENDL3SS]

Originally Posted by Colinv6

Thank you!! Looks great. So no rubbing at all and are you using spacers?


Lastly.. these or 763’s?! I’ve been debating on wheels for weeks now

15mm spacers all around. No rubbing. I had 763M as well and they give a better track look. Hard to pick and I would have both if I had space.

[stuart255]

The mass of the wheel doesn’t tell you anywhere near the full story.

You can have a wheel that is heavier, but has more of its mass closer to the hub and thus has a lower rotational inertia than a lighter wheel with more mass at the rim.

It’s called the “radius of gyration”.

In engineering terms, the radius of gyration (k) is defined as the square root of the moment of inertia (I) divided by the mass (m) of the wheel.

The formula is:
K = [ I / m ] ^ 0.5

People confuse rolling resistance (which is more down the wheel bearing) with rotational inertia which is really the radius of gyration and the wheel + tire mass.

Tires are pretty much the most important component of any car, changing up the wheels and tires without really knowing what you are doing is just a lucky dip for driving performance. But hell we all do it.