17” vs 18” wheels - pros/cons for 90/10 street/track?

[Maxhouse97]

Looking for benefits of each, really leaning towards 17” for weight and cost (especially if they clear 996 brakes with ZCP rotors). Can is on stock suspension for now. I do realize less tires every year are being made in 17”. Would like something that reduces unsprung weight and will be suitable for the track. Have my eyes on ARC8s. Thanks.

[erickhoyos]

Easier to have 18” wheels to clear most bbk than to struggle with 17” wheels that might not fit with your setup. 18” ARC-8s are light, I had squared 18x10.5 and they were significantly lighter than stock 18” style 67.

[liam821]

There is also a much wider selection of tires in 18".

[Sharocks]

I have three sets of 17's for the M3. While the tire selection for a street car is abysmal, for track setups there are a few options. If you can make them clear brakes you should be good. I only went 17's due to them being local and fitting really well. I would go 18's if you are ok with running Arc8's.

[01SG]

I believe 17" Apex wheels will clear up to 355mm rotors-it may be 345. It's stated on the website somewhere, but they will definitely clear ZCP rotors.

I got the 17x9.5 set squared and love it. Not sure how much steering feel changed with the taller sidewall, as changing the wheels and tires made a significant difference in their own right, so it's better regardless. Comfort is definitely a big plus as well, and the rim is very well protected. As far as I'm concerned there's no downside.

Michelin's are still over a grand, but I can't complain about $700 for a set of Continental's.

[Maxhouse97]

I have to say I was leaning towards the 17s but then looked up the tire sizes and the most popular seems to be 255/40-17, which is a full inch smaller in diameter than stock. Does not seem ideal. I liked the low weight and cost, but now think I’m leaning towards 18s.

I intend to upgrade to 996 brakes with ZCP rotors.

[bigjae46]

I have 17x10 ARC8s. Feel and performance...about the same. If you're running R-Comps or NT01s then its kind of a no brainer if youre on 275s. 17s are just as good but they cost less.

The 17" Arc8's clear 355mm ST40 stoptechs.

I'm going to 245/40R17s Hoosiers or BFG R1s - shortens up the gearing.

[r4dr]

I have to say I was leaning towards the 17s but then looked up the tire sizes and the most popular seems to be 255/40-17, which is a full inch smaller in diameter than stock. Does not seem ideal. I liked the low weight and cost, but now think I’m leaning towards 18s.

I intend to upgrade to 996 brakes with ZCP rotors.

Smaller diameter tires = effectively shorter gearing. Can be great on the track and for acceleration!

[Obioban]

I have 17x10 ARC8s. Feel and performance...about the same. If you're running R-Comps or NT01s then its kind of a no brainer if youre on 275s. 17s are just as good but they cost less.

The 17" Arc8's clear 355mm ST40 stoptechs.

I'm going to 245/40R17s Hoosiers or BFG R1s - shortens up the gearing.

The 17x10 ET 25 ARC8s also clear 355mm brembos and 996 conversion BBKs. I run them as my track setup, as well.

I wouldn't consider it an entirely no brainer-- tire selection is a lot more limited on 17s than 18s. But, there are enough tires, as they are cheaper, so I keep running them...

... though I've been considering stopping, as I really prefer 9.5" ET35 to 10" ET25 as a track setup...

[Sharocks]

My Forgelines are 17x10 ET38 and while they needed a spacer to clear a Brembo 355 setup up front, they weigh nothing, tires are cheaper and for tires that you will go through quicker it was a no brainer.

OP don't run 255's. Find some 275s to run on them.

[bigjae46]

The 17x10 ET 25 ARC8s also clear 355mm brembos and 996 conversion BBKs. I run them as my track setup, as well.

I wouldn't consider it an entirely no brainer-- tire selection is a lot more limited on 17s than 18s. But, there are enough tires, as they are cheaper, so I keep running them...

... though I've been considering stopping, as I really prefer 9.5" ET35 to 10" ET25 as a track setup...

For R-Comps it’s not that different. Street tires...you have to drop down to a 255/40R17


Sent from my iPhone using Tapatalk

[Estoril]

Just to be clear - 10% track is a LOT of track days. A helluva lot. You might think about that number.

17/18 doesn't really matter for a street car. I'd be more focused on those drilled rotors.

[S14]

I'm looking forward to running 17's for track duty.

[bigjae46]

I don’t think a 255 is going to be that different than a 275 as far as lap times. I think most don’t even use the entire section width even on 10” wheels. A 255/40R17 might even be faster.

Many 255 r-comps are going to be about the right size on a 10” wheels.

255 street tires are going to look stretched on a 10” wheel. Going to look perfect on 9.5” wheels.

To run a 275...you kinda need to roll fenders and add negative camber. Not really street friendly.

I’m going to run 245/40R17 R7s or BFG R1s which should stretch the tire just a tad.

Just some data points.

For street, I’d run 18s due mostly to aesthetics.

I’ll repeat. For the track, it is mostly a no brainer ONCE YOU RUN R-Comps.

I run NT01s for HPDE. I save about $150 per set of tires which adds up. Also about 2lbs less unsprung weight per corner. I’d argue that I get a little more life from my 17s but don’t have enough data yet.

On my 330ci - I was faster on 245/40R17s vs 255/40R17s on 9” wheels. Lap times prove this. The car felt faster.

I’ll report back when I do a weekend on 245/40R17s in the M3. I’m expecting a nice lap time decrease.


Sent from my iPhone using Tapatalk

[Maxhouse97]

Ok now you guys got me thinking 17s. You’re right on 10% being ally, probably closer to 95/5. But isn’t 17” tire availability only going to get worse as time goes on? I don’t really care about aesthetics, I kind of like the meaty tire look.