Why would BMW create a heavy wheel for the GTS.

If my little searching has served me correctly, I have concluded that the ZCP 359M wheels and the GTS wheels are the exact same (except for the color) ??

Specs are:
19X9 front 26.0 lbs
19X10 rear 26.8 lbs

There is speculation that the GTS wheels measure 1/2" more, but almost essentially the same. Someone mentioned that they cheaped out for heavier wheels for cost efficiency for consumers. But why not create a lighter version for the GTS.

So my question is, why would BMW put such a heavy wheel on the GTS seeing as its a track oriented car?

I apologize in advance if this is a repost of any kind.
Thanks.

Strength and weight go together. Both the GTS and the ZCP are "production" cars destined for hundreds of thousands of kilometers in the real world. Strong wheels are good.

mk599 wrote

If my little searching has served me correctly, I have concluded that the ZCP 359M wheels and the GTS wheels are the exact same (except for the color) ??

Specs are:
19X9 front 26.0 lbs
19X10 rear 26.8 lbs

There is speculation that the GTS wheels measure 1/2" more, but almost essentially the same. Someone mentioned that they cheaped out for heavier wheels for cost efficiency for consumers. But why not create a lighter version for the GTS.

So my question is, why would BMW put such a heavy wheel on the GTS seeing as its a track oriented car?

I apologize in advance if this is a repost of any kind.
Thanks.

JAJ wrote

Strength and weight go together. Both the GTS and the ZCP are "production" cars destined for hundreds of thousands of kilometers in the real world. Strong wheels are good.

But the optional 19 inch wheels are lighter and stronger

N8dawg wrote

But the optional 19 inch wheels are lighter and stronger

They are indeed lighter, but how do you know if they are stronger?

e1000 wrote

They are indeed lighter, but how do you know if they are stronger?

In theory they should be as they are forged, wich the zcp is not.

ee8 wrote

In theory they should be as they are forged, wich the zcp is not.

+1, opt 19s are forged, 18s and ZCP are cast, which is a more fragile form of wheel

Another myth...

In terms of material properties, forged is obviously stronger than cast. But remember, material strength is measured per UNIT AREA.

Therefore, as a wheel, you can add more material (more area) to make it stronger. This is why a properly designed cast wheel can be just as strong as a forged wheel, but obviously the cast version will be heavier.

^

If the GTS wheel was designed specifically for the GTS, why does it need a spacer?

I think it was just a cheap option to run with the ZCP wheel but in a different colour

plus, I have yet to see difinitive proof of if they are actually cast and who makes them.

Point being, none of us truly know just how strong the wheels are. Most likely, both are far stronger than required for the performance of the car. Potholes are another story and should be avoided at all costs either way.

Anyone make a 8000 tons forged ZCP wheel with OEM setting?

e1000 wrote

plus, I have yet to see difinitive proof of if they are actually cast and who makes them.

Point being, none of us truly know just how strong the wheels are. Most likely, both are far stronger than required for the performance of the car. Potholes are another story and should be avoided at all costs either way.

They are cast and sure they are plenty strong. This is not the first time I limited production BMW came out with cast wheels. The wheels on the E46 CSL were cast (technically "spun cast" but whatever) - I had those wheels and never had an issue in 40k miles with plenty of potholes.

Fanta wrote

Anyone make a 8000 tons forged ZCP wheel with OEM setting?

RAC's RG63 is just that.

alpina527 wrote

If the GTS wheel was designed specifically for the GTS, why does it need a spacer?

I think it was just a cheap option to run with the ZCP wheel but in a different colour

Ian,

Care to elaborate? I didn't realize that the GTS has spacers.

signes wrote

They are cast and sure they are plenty strong. This is not the first time I limited production BMW came out with cast wheels. The wheels on the E46 CSL were cast (technically "spun cast" but whatever) - I had those wheels and never had an issue in 40k miles with plenty of potholes.

Not trying to doubt anyone, but I really would like to see difinitive proof. I too went by what I read here and on other forums, but when I went looking I couldn't find anything that said where the ZCP wheels were made and by what process they were made from.

So I have no idea who is right and who is wrong regarding the forged question, but the 2011 M3 Sales Brochure identifies the "sporty 19" Y Spoke (Style 359M) forged alloy wheels" to be part of the comp package. You can download the brochure from BMWNA's website, and it's on page 52/53 of 70. I realize this doesn't mean anything if they are wrong, but that is what they are claiming.

Mike

alpina527 wrote

If the GTS wheel was designed specifically for the GTS, why does it need a spacer?

I think it was just a cheap option to run with the ZCP wheel but in a different colour

Because it's still a street legal car.

aajami wrote

Ian,

Care to elaborate? I didn't realize that the GTS has spacers.

Aajami, I think I saw you a few days ago on Culver near the 90, was it you? I saw a space gray E92 M3 with ZCP wheels. I was in the MR ZCP E92 M3.

Dave

alpina527 wrote

If the GTS wheel was designed specifically for the GTS, why does it need a spacer?

I think it was just a cheap option to run with the ZCP wheel but in a different colour

Why would the GTS wheels require a spacer. I am running a 255/35/19 front along with a 285/30/19 rear with no spacer on my ZCP.

Dave

aajami wrote

Ian,

Care to elaborate? I didn't realize that the GTS has spacers.

Yes, the GTS uses spacers as standard to push the wheels further out in the arches. Surely if these wheels were specifically designed for the GTS they would have the correct offset built in? I think the spacers are 10mm BTW.

Dave07997S wrote

Aajami, I think I saw you a few days ago on Culver near the 90, was it you? I saw a space gray E92 M3 with ZCP wheels. I was in the MR ZCP E92 M3.

Dave

Ha! I was wondering if that was your car, Dave. Yeah, I saw you. Here's my post about it...

http://www.m3post.com/forums/showpost.php?p=8666089&postcount=1189

alpina527 wrote

Yes, the GTS uses spacers as standard to push the wheels further out in the arches. Surely if these wheels were specifically designed for the GTS they would have the correct offset built in? I think the spacers are 10mm BTW.

I find that odd for two reasons. One, that BMW would use a spacer at all. Two, that BMW would use the one size spacer that doesn't actually fit on the car.

http://www.m3post.com/forums/showpost.php?p=6445284&postcount=5

Do you have a link to more information?