Tire Dilemma: 9.5-inch wheels (BMW 219s)

[WarrantyTracker]

I'm running a square set of BMW 219 rears for track wheels. They are 18x9.5.

I'm finally ready for some step-up tires, according to my instructors. Lack of traction on summer street high performance tires has become a limiting factor for me.

My thoughts turned immediatedly to Nitto NT-01s, until I checked sizing. There is nothing between 275 amd 245. Yes, either tire will fit on a 9.5-inch rim but based on field reports the 275 will probably bulge and the 245 will probably stretch. Either way, handling reportedly suffers.

Conventional wisdom suggests wheel width for track use should be 100-110% of tread width, so I'm looking for 255s or 265s.

One option would be BFG R1s in a 265.

Another direction would be the Nitto NT-05s which are available in 255 and 265. But I'm not sure how much of a step up those would be over any other summer street high performance tire. Though they would be a step-up over the Sumitomo HTR IIIs I'm using now.

R888s are available in more sizes but I'm not interested in something that soft.

Any experience would be appreciated.

[LiM3y]

Nitto NT-05s are a good hard-wearing tire to step up from pure street tires. They don't have the blocks and sipes of street tires, so handle the heat better, but squeal a bit close to the limit to help you keep on the black stuff. They grip better than the 200 wear rating might otherwise suggest, especially when run in. Are Ventus RS-3's available too? I only looked at 275's for 18x10. Another solid HPDE tire for a stock M3.

I have read R888's don't work well on the heavier E9X M3s. They are a great tire for E46s and prior years, but have a tough time with the heavier, more powerful E9X and get shredded.

[Kunman]

your other option would be running square 255 R888s.

[drchuck72]

RS3s are available in 265 35R18. I am running those on 18x9.5in ADVAN RS on the fronts. They are great on the track.

The following tires are available in 265 35R18. All are Extreme Performance tires so good track tire and in some cases, reasonable value (as track tires go):

Bridgestone RE11
TOYO Proxes R1R
Yokohama ADVAN NEOVA AD08
Dunlop Direzza ZII (Star Spec) - A friend is running these on his M Coupe. He really likes them
Kumho Ecsta XS

If you want to go one step further, there is the Streetable Track Competition category. However, these are considerably softer and more expensive (to buy and obviously, you will have to replace them sooner):

Michelin Pilot Sport Cup 2
Pirelli P Zero Trofeo
Yokohama ADVAN A048.

I've heard about guys with Porsches who only got 2 track days with the Trofeos. I would suspect that the PSC2 is almost as bad.

[CSBM5]

275/35-18 are fine on a 9.5" wheel. In fact that is the "standard" wheel width for that size tire. I've used them on my E39 M5 for over 10 years, square setup all around, and I've used NT-01s since 2007 in that size on 9.5" all around on the M5 for many track events and autocrosses...no issues, excellent results.

Ah, just remembered...I can even help you out with in-action video of an NT-01 275/35-18 on a 9.5" wheel, up front, on my M5 at the Perf Center track a while back: https://www.youtube.com/watch?v=b5JqbFQ84TY

[drchuck72]

Come to think of it, before I went to the RS3s, I was running 275 35R18 NT05s on my 18x9.5in ADVAN RSs.

[s85e90]

I am running a 245/40 Nitto on m front Volk that are 18x9.5 and there's no stretch at all and it's still w/in guidelines to be acceptable. Looks great IMO.

[The HACK]

If you look at the typical tire specs on manufacturer's pages, let's take, for example, the tires I'm using now...Maxxis RC-1 @ 275/35/R18:

http://www.maxxis.com/catalog/tire-450-107-victra-rc-1

You'll see the sectional width as 11.2" and the measuring rim width as 9.5". It doesn't mean the tires are "bulging" because the sectional width is significantly wider than the rim width, nor does it mean it'll take an 18" x 11" wheel for the sidewalls to sit squared.

It actually means, the maximum sectional width as measured, 11.2", was achieved on a 9.5" rim. I know, funky right? When you're looking at tires that fit your specific wheel, find widths (and aspect ratio) that leaves the overall diameter as close to desired that has the sectional width as measured on the same width rim as you have.

What that means, is you SHOULD run a 9.5" rim with the 275/35/R18 if you choose to use the NT-01:

https://www.nittotire.com/Tire/Competition/nt01#size

But wheels as narrow as 9" and as wide as 11" can in fact work. It's just that at those sizes the sectional width as measured, and in turn, the actual width of the contact patch, is smaller than the "as measured" 9.5" wide wheel.

As for the bulge/stretched look, that's all about individual preference/needs. I happen to have 4 9.0" wide 18" rims that allow me to run squared 275 wide Maxxis on hand with the right offset, so I am using that instead of going out and getting another set of 9.5" wide wheels, or getting 255s which are not available anyway.

Plus, going from summer street tires to R-Comps is going to be such a HUGE upgrade that how the sidewall sits under those rims is the least of your worries, to be honest.

[surlynkid]

you can run 275/35 on 18x9.5 all day. I have a friend that runs them on his E90 M3 without issue, and he can get around the track.

[bigjae1976]

I've got 275 PSS on square OEM 18x9.5s. No issues.

What does lack of grip being a limiting factor mean? I would have asked why do they think you should step up and get stickier tires. Because it will make you faster? In an HPDE environment, I would consider that bad advice coming from an instructor.

I'm not sold on this whole tires are holding people back thing. I had a revelation...instructed a guy in a 370Z who started in the front of the group and had 2 people pass him the entire 20 minute session. He was driving on 3 snow tires and an all season. I have no idea why he would do that...but THAT is enough proof to me that this statement rings true...

Mod the driver...not the car.

Keep your Sumi's and go kick some a$$!

[WarrantyTracker]

Thanks everybody! Lots of useful information here. Gives me more to go on as I make my decision.

Bigjae, buddy, thanks for your advice. Mucho respect for you for the time you dedicate and the risks you take in instructing your students. No offense taken or intended, but my driving instructors are in a better place (the right seat) to instruct me.

[lcrain]

Really think going straight from a mediocre street tire to a r-comp is not the best course of action.

I would recommend looking at some of the extreme performance summers (hankook rs3, dunlop z2 etc.). You will gain a LOT of grip over the sumitomos and they will last much longer than an R-comp. Not sure why your instructor thinks you need to go to that grippy of a tire so quickly. More grip can be detrimental to a learning driver.

[admranger]

One step at a time. Go to the RE11's in 265/35. I have RE11's all around on both of my M3's. Fantastic track tire.

When you can drive the car with a four wheel drift (not some ridiculous rear end hanging out drift), but a real 4-wheel drift through the corners, then you can think about track tires. It's more fun on street tires anyway. Stickies just hide too many flaws and every other wearable component takes a higher load (including the driver -- oh yeah, and us instructors).

If the economics of street tire vs. track tire change back to what they were in the 1990's, I'll reverse my advice above (because that's the excuse I used to use when Michelin MXXs were 2x the cost of Toyo RA1's).

[Richbot]

9.5" wheel is perfectly fine for a 275/35-18. That's what I would do. Don't let perfection be the enemy of progress

[WarrantyTracker]

Originally Posted by admranger

When you can drive the car with a four wheel drift (not some ridiculous rear end hanging out drift), but a real 4-wheel drift through the corners, then you can think about track tires.

Yeah, I'm there. The less instructor time I spent tracking my E92 M3 during the process and the more I tracked and skid-padded old, light, low-power cars with no nannies, the faster I learned. But some times those old light cars need to spend stretches in my garage getting their guts replaced, and I have to track the E92.

Thanks again guys for all the tire options. It really helped me decide.