245/35r19f & 275/30r19r vs. 265/30r19 squared [Squared rear ZCPs]

[cornerbalanced]

Picking up a squared rear set of ZCPs that will need tires shortly.

Currently debating between 245/35r19f & 275/30r19r and 265/30r19 squared. From what I have read on the forums, I shouldn't have an issue with rubbing with 265/30r19s up front so long as I have over -2 degrees of camber up front. I am worried about running 30 profile tires squared...that's practically a rubber band. I know 265/35r19 squared isn't feasible. A buddy of mine is currently testing out 255/35r19 squared (MP4S star spec) and reported on full lock / close to full lock he rubs a solid amount. No good.

My primary question is, do you guys think there would be a quantifiable difference in terms of mechanical grip and performance between 245/275 staggard and 265 squared? I go to the canyons fairly regularly, and the track a couple of times per year, so performance is ultimately a factor.

[Tbonem3]

265/30/19 is my vote, but I wouldn't have big, heavy square 19s for a dual duty car, myself.

[cornerbalanced]

265/30/19 is my vote, but I wouldn't have big, heavy square 19s for a dual duty car, myself.

It’s COMPLETELY illogical on my end. I have always dreamt of owning a ZCP car with squared ZCP wheels (ultimate OEM+ in my opinion) so I feel obligated to do it now that I have the opportunity.

When I have the money I’ll buy a spare set of 18”s for track use, and have the squared ZCPs for street use; but for now that money is going towards maintenance, suspension work, headers, etc.

[Tbonem3]

I hear you. I debated for a long time. I had a mint set of CSL wheels. Had my fun looking at them, taking pics, but then decided to sell them as they "ruined" every other aspect of the car.

I will say, however, with fresh PS4S, the 30 profile tire was not that bad. I had had 255/35/19 PSS a few years earlier and it was harsh, but the smaller 30 profile, in the newer PS4S, was a lot more comfortable & quieter - couldn't believe it.

[cornerbalanced]

I hear you. I debated for a long time. I had a mint set of CSL wheels. Had my fun looking at them, taking pics, but then decided to sell them as they "ruined" every other aspect of the car.

I will say, however, with fresh PS4S, the 30 profile tire was not that bad. I had had 255/35/19 PSS a few years earlier and it was harsh, but the smaller 30 profile, in the newer PS4S, was a lot more comfortable & quieter - couldn't believe it.

We’ll see how long I’m able to last aha.

And in that case I won’t feel so bad going with 30 profile tires — super happy to hear that.

[Gt4]

30 profile will look way better than 35. Also, total diameter is smaller than OEM so you will get better acceleration.

OEM ZCP aren’t the strongest wheels and are heavy, almost 5lbs heavier per wheels vs an Apex Arc8 in 19’’. But I understand, I also want ZCP on one of my M3 cause they look good.

[maw1124]

… they "ruined" every other aspect of the car…

Please elaborate on this. Thanks. I’ve been literally looking at the same issue for a different reason this morning.

maw

[Sharocks]

I've been running squared OE CSL rears for about 6 years now.

Best setup for me has been 265/35/19 square.

It's a heavy wheel up front, and I like the additional sidewall.

A 30 up front is gross lol.

[cornerbalanced]

I've been running squared OE CSL rears for about 6 years now.

Best setup for me has been 265/35/19 square.

It's a heavy wheel up front, and I like the additional sidewall.

A 30 up front is gross lol.

30 profile squared just scares the shit out of me. Plus I’d have to slam the car even more to get proper fitment, which I’d like to avoid …

Assuming you have more than -3deg of camber and rolled fenders?

[Tbonem3]

Please elaborate on this. Thanks. I’ve been literally looking at the same issue for a different reason this morning.

maw

Ian probably has this full list on his clipboard, but quickly:

More expensive tires, less comfort (harsher, more noise), more unsprung weight, more rotational mass.

And, as the OP alluded to, you have to lower the car a little more for it to look best with with 19s whereas a little more fender gap works with the meatier 18" tires.

[maw1124]

Got it, so mainly a choice of 18 v 19, looks like.

maw

[Sharocks]

30 profile squared just scares the shit out of me. Plus I’d have to slam the car even more to get proper fitment, which I’d like to avoid …

Assuming you have more than -3deg of camber and rolled fenders?

Yea I'm running -3.5 up front and -2.5 in the rear.

Car actually is setup really well for these wheels but they are big.

For reference, I use the same alignment setup for my 17x10 setup running 275/40/17 square.

[maw1124]

Is anyone making bespoke, lightweight forged monoblocks for these cars, or is it only the couple usual suspects that almost everyone has? I'd be down for 18x9/10 if they existed in the proper offsets (and the whole world wasn't wearing them).

maw

[Tbonem3]

Bimmerworld and Apex have cheaper, forged chineseum wheels now. There's RAC, if you can find a set (although those might all be 19s, can't remember). Might be some MORRs floating around. Supposedly, our favorite GB orchestrator is looking to make forged CSL/ZCL (style 359 AND 163 iirc) in 18 and 19.

[maw1124]

I love the style 666 but I just can't live with that number and the style 220 offsets are wrong.

I actually don't mind 19" (bought the car that way, see no reason to change) but am not averse to lighter 18s. I'm tempted to ask why the factory made the 19" fronts so narrow in the first place, but I'm not sure anyone really knows. 8.5" wide fronts would have nailed the brief IMO, but once I'm in the market, I may as well go for what I think is best, which is 9" wide front, 10" wide rear, even (or especially) if that means losing weight down to 18".

maw