[NCRob]

Simple physics dictate 35 series tires on 20s will absorb shock better and ride more “comfortable” than 30 series on 21s. But, from those who’ve done both, how much is that difference. On decent roads everyday driving is it minimal or does it feel like you traded your luxury ride for a beater? I like the look of more wheel and less sidewall myself on this platform (as opposed to my 4wd truck) but still wavering between the two. I’m looking particularly at the signature SV104s priced $4650 for 20s and a “special price “ of $5k even on the 21s. Signature recommends the 21 for looks and resale for what it’s worth. It also appears that the wheel weight delta is washed by the tire weight delta.
Tires likely will be Michelin PS4 285/295 either way. And neither setup will require spacers.

I’m running 285/295 with 12mm/5mm spacers now on the boat anchor 706 wheels for winter so expecting quite a difference in weight either way.

[pbonsalb]

If your roads are good, 21s are fine. It is not like you are going oversize—BMW sold the car with 21s as an option. In my area, we have winter that creates frost heaves and breaks up older roads. If you have a 21 or newer with the M8 struts, the ride should be better than in an 18-20.

[josec70]

I’ve had both on this F90 M5 platform and the difference is minimal, in my opinion, especially if you have good roads.

21’s look great on this car.

[NCRob]

Got my order in for gloss black 21” Signature SV104s
F: 10 inch, ET 20, 23 lbs
R: 11 inch, ET 26, 24 lbs
$5k total shipped
4 week lead time (we’ll see)
Going to install my KW HAS and run PS4 285/295 30s
Also have a set of Dinan mono balls to put on

[ResIpsaLoquitur]

Originally Posted by NCRob

Got my order in for gloss black 21” Signature SV104s
F: 10 inch, ET 20, 23 lbs
R: 11 inch, ET 26, 24 lbs
$5k total shipped
4 week lead time (we’ll see)
Going to install my KW HAS and run PS4 285/295 30s
Also have a set of Dinan mono balls to put on

Nice list of mods! Can’t wait to see.

[shawnhayes]

Originally Posted by pbonsalb

BMW sold the car with 21s as an option.

???????

When, what wheel?

Shawn

[ResIpsaLoquitur]

Originally Posted by shawnhayes

???????

When, what wheel?

Shawn

Yes, I’d love to know this, too. I can’t recall that ever being the case, but I could be totally wrong!

EDIT — Now that I am thinking, IIRC, there is an owner here, I believe from the UK with a BSM pre-LCI who has gloss black 21s that he said were on his car from BMW. I can’t recall anything beyond that, and I could even be remembering that wrong honestly.

[pbonsalb]

Originally Posted by shawnhayes

???????

When, what wheel?

Shawn

I was mistaken. Sorry for the confusion.

[Mccarlin]

POst a pic when you get them installed ive been looking at getting the same wheels.

[M5VanHalen]

Originally Posted by josec70

I’ve had both on this F90 M5 platform and the difference is minimal, in my opinion, especially if you have good roads.

21’s look great on this car.

I agree. I have 21" BBS FI-R in Satin Black on my 2023 M5 and they make a huge difference in looks over the 20" OEM wheels. Even with the H&R Springs, I do not notice much of a difference in ride quality. But, the difference in looks are a lot.

[NCRob]

What size tires are you guys running on the 21s?

[josec70]

Originally Posted by NCRob

What size tires are you guys running on the 21s?

I ran both 275-295-30 and 285-295-30.

[916_M5]

I am lowered on HR F90 Springs and also on 21" wheels.
I will say I noticed a bumpier ride going 21's vs 20's rather than lowering my car.
I did not notice much of a difference in comfort with my springs.
If your roads are more or less good roads, yes go 21's.

[NCRob]

Wow, while I haven’t received yet to inspect in person, thus far I am really impressed with Signature Wheels. Ordered on 2/18, custom built and shipped 3/9! I’m sure they’ll look just as good in person. These guys are really spot on with customer service. Very responsive to my litany of questions. Lol! I think the pricing is good too for 21” this light. Before they see the road I’ll slap a couple coats of GYEON Rim on them.

[josec70]

Originally Posted by NCRob

Wow, while I haven’t received yet to inspect in person, thus far I am really impressed with Signature Wheels. Ordered on 2/18, custom built and shipped 3/9! I’m sure they’ll look just as good in person. These guys are really spot on with customer service. Very responsive to my litany of questions. Lol! I think the pricing is good too for 21” this light. Before they see the road I’ll slap a couple coats of GYEON Rim on them.

Very nice!

[ResIpsaLoquitur]

Originally Posted by NCRob

Wow, while I haven’t received yet to inspect in person, thus far I am really impressed with Signature Wheels. Ordered on 2/18, custom built and shipped 3/9! I’m sure they’ll look just as good in person. These guys are really spot on with customer service. Very responsive to my litany of questions. Lol! I think the pricing is good too for 21” this light. Before they see the road I’ll slap a couple coats of GYEON Rim on them.

These looks awesome! Can’t wait to see them on your car, especially considering your car has one of the most beautiful front ends on the forum IMO.

[NCRob]

Coated with Gyeon rim and installed 285/295 PS4s yesterday. Need to dress tires and calipers this weekend. I like it but guess I just need to get used to the lower profile tire and big wheel look a bit as it’s much different than what I had before for sure. I did post in other thread about painting those rotor hats black as they show much more now. Also considering powder coating calipers black but buddy says I’m nut lol!

I also have a KW HAS kit sitting in the garage debating on using or not (scored a really good deal on from forum member here!). What do you guys think of that?

Have only driven 1 mile from tire shop so far so no thoughts on performance or comfort yet. Also, these PS4s give me the illusion they are SO much wider than my AS4s same size for some reason

[NCRob]

hmm, just noticed they put the FP & RD tires on wrong wheels. I thought that FP looked stretched - Its a 285 on a 11 inch Wheel! Stupid Question: I'm going out of town (not taking m5) Will it hurt to have that tire on there sitting ingarager for a few more days? Permanently stretch/deform it?

[windtendo]

Originally Posted by M5VanHalen

I agree. I have 21" BBS FI-R in Satin Black on my 2023 M5 and they make a huge difference in looks over the 20" OEM wheels. Even with the H&R Springs, I do not notice much of a difference in ride quality. But, the difference in looks are a lot.

Post some pics of the satin black FI-Rs on your ride! I wanna see!

EDIT: disregard, just found your post with all the pics

[josec70]

I would throw the KW kit on the car and lower all four corners a bit.

[NCRob]

Got an appointment 2 weeks to lower and install Dinan Monoballs. Local shop I used for everything for years. Owner former BMW tech. He doesn’t think any issue painting the hat itself and I got a duplicolor brush kit might do myself if I get around to it or just have him do it when he racks it. I will say after driving now a few days it actually feels like it accelerates faster. Likely partly placebo. Takes bumps a little harsher but not bad at all really. The look is growing on me and I just need to get those tires dressed! Also PSI I’m running is 33/34. Sound right?

[Redacre]

NCRob I wanted to bump your thread and ask you how you feel about the 20" vs 21" now that you've had it for a few months. I am in the same situation as you were weighing pros and cons and would love to hear your opinion. Only difference is that I do not plan on lowering my car (my M4 was lowered and I just don't want to deal with that again).