ledbette

Are these track-only tires or street/track combined?

Apex Wheels

If you plan to continue running the PS4S or move to a Hankook RS-4 then those are good sizes. Unfortunately, the RS-4 is the only track tire available for those sizes. If you are coming from a 245 front tire, fitment may be more picky about front strut top mount location in the OEM slotted mounting locations.

- Brandon

ledbette

You'll have more options at 245/40/18 and 275/40/18.

L76

But less contact surface area?...
-L76

L76

Track only.

-L76

Apex Wheels

The tires will be "narrower" but as ledbette said, you have much better track tire options to choose from in the 245/40/18 and 275/40/18. Something like a 245/275 Nankang CR-S, Yokohama A052, or Yokohama AD09 will still be a faster track tire. The RS-4 should be used if you want something that will last a long time.

- Brandon

ledbette

1. As far as surface area goes, you'll want to look at each tire to determine exactly how much tread width you actually have. A 245 tread width is not the same for all makes and models of tire. A 245/40/17 Hoosier R7 for example is a full half inch wider than the "same size" Toyo RR (these are race tires, but you get the idea). You can look at the tire rack web site and get an actual measured tread width and diameter for each tire in the size you're considering.

2. The tread design, compound and sidewall construction can make a lot more difference than 1cm (4% increase) in tread width or a few percentage decrease in tire diameter will give you in contact patch. An A052 in 245/275-40-18 is going to give you a lot better grip than a 255/285-35-18 PS4S.

3. A PS4S is really a street tire. Tire Rack puts it in the Max Performance Category. While it's OK for the track, something in the Extreme Performance Category will typically give you better performance. They typically won't last as long on the street... Except maybe the Hankook RS4s. Those things wear like iron. The RS4 isn't the fastest, but the longevity is hard to beat.

I personally prefer something a little more sticky, but that is where the next consideration comes in...

4. What tire you pick depends a lot on what you're attempting to accomplish. Do you want the best and most-consistent lap times for a 20-min session (for HPDE), peak performance for a couple laps in a 20-min session (for TT), or consistency over a long duration and long life (endurance). There are a lot of tradeoffs to be made.

You can look at the Tire Rack testing and also places like Grassroots Motorsports (which for a nominal online subscription rate, you can get access to their tire reviews) for ideas. But, if you've tried the PS4S already, I'd suggest trying something different and seeing what you like. Worst case, it's not a lifetime decision. You'll get plenty of opportunities to try others.

rr_gts

Which tires do you like/recommend for each category?

ledbette

One other thing regarding #1 above. I know a 245/275-40-18 combination works for an RS4 on a 981 using OEM 987 rims because that's what I have on now, but I don't know about a 255/285 combination. The RS4 is 0.7" wider in the front and rear than the PS4S in a 255/285-35-18 size. The guys at Apex may know whether or not it fits based on info from their customers. You might also ask on Planet-9.com. I think that site has a little better following than RL.

ledbette

TBH, I don't really have a recommendation from personal experience. I semi-retired my 981 from track use when I bought an E36 M3 race car a few years back, however I do still take it out a few times a year.

That saying, I've always liked the Nitto NT01 for HPDE, especially if you're using an semi-aggressive track brake pad like an Pagid RSL29. However they seem to have very limited sizes available currently, and Tire Rack shows them on back-order. Those are also getting quite old, so I would probably try something different next time out.

I have a set of RS4's on my track wheels that wear like iron, so much so that I can't wear those stupid things out and try something else. I also know quite a few endurance racing teams really like those. So I'd probably go with those for endurance and longevity, but they are just not as fast as some of the others.

I have a friend who does TT on a high horsepower LS-swapped Mustang, and he swears by the A052's. I've heard they are great for that hot lap or two, but start to fall off when they get hot over a full 20-minute session, especially on his heavy car. I'd probably give those a try for my next set.

I'd really take a look at the online reviews by TireRack, Grassroots Motorsports, and whoever else might have a head-to-head. Or, if you DE with other 981's, see what they have tried and what they like and dislike.

L76

Was thinking of trying the Nittos, but can only find the NT 555 G2s…. Anyone running these?

-L76

ledbette

Why are you concerned about a smaller size when you would consider using NT 555's? The NT555 is two classes below a serious track tire.

brewerbry

I run 265/35/18 and 295/35/18 on my apex that are 9" up front and 10.5" in back. You need extra camber for them to fit but they are great sizes especially with Nankang CR-S. Hoosier just released a 200 TW tire that is intriguing - have to see how those get reviewed

Apex Wheels

An aggressive setup but a good one for sure, are you getting that to work with camber plates or just pushing the struts all the way inboard in the factory slotted mounting holes?

am also looking forward to trying the new Hoosier Track Attack Pro when they release my front tire size next year.

- Brandon

dps214

Try it at your own risk but my experience has been that those sizes are small enough in diameter that fender clearance isn't an issue as long as you keep a reasonable ride height, even on stock suspension (caveat: I had GT4 swaybars, but otherwise stock PASM suspension).