Advice on picking the best wheel and tire combo

Tim
Update by Tim Suddard to the Porsche 911 Carrera project car
Aug 22, 2023 | Porsche, 997, 911, Porsche 911

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Are Porsche Lobster Claw wheels timeless beauties or ugly abominations that should be banished to the back of the garage?

Doesn’t matter how they look: They’re heavy and a bit too narrow up front.

Even though our Porsche 997 wore fresh Bridgestone Potenza Sport tires on those Lobster Claws, we knew we could do better.

Our ideal wheel-and-tire setup: one that makes this car safe and fun for an occasional track day without ruining the ride quality. Oh, and we wanted to keep the looks on the subdued side.

While we don’t have any plans to make this 911 into a dedicated track car, our initial testing at The FIRM on the stock-size tires did reveal some limitations. As expected, the Porsche simply pushed too much.

Lots of companies offer wheels for Porsches. We’ve been very happy with the Apex wheels on our E46-chassis BMW M3: They’re lightweight and offer timeless looks as well as motorsports-friendly sizes. So we revisited the brand.

Apex also offers a rather uncommon 50% replacement program. While most wheel companies won’t warranty anything used on the track, Apex will replace a damaged wheel for any reason for up to two years after purchase.

The brand offers a variety of flow-formed and fully forged motorsport-oriented wheel designs that are engineered specifically for each Porsche chassis, including center-lock applications. 

So, what size wheels for our Porsche 997?

Instead of guessing and hoping for the best, we talked to Apex and consulted the company’s fitment guides for the Porsche.

The details on our stock Lobster Claws:

  • front wheels: 19x8 in. ET57, ~22 lbs.
  • rear wheels: 19x11 in. ET57, ~27 lbs.
  • 98 lbs. total
  • front tires: 235/35R19
  • rear tires: 295/30R19

Based on Apex’s experience, the company offered three options that would deliver more grip within the factory fenders.

18-inch Option 1

  • Apex SM-10
  • front: 18x8.5 in. ET45, ~20.6 lbs.
  • rear: 18x11 in. ET60, ~22.4 lbs.
  • 86 lbs. total.
  • wide up front yet 12 lbs. less than the stock 19-in. wheels.
  • front tires: 235/40R18 or 245/40R18
  • rear tires: 295/35R18
  • Apex Notes:
    • These fitments are a direct fit and do not require suspension/alignment modifications.

18-inch Option 2

  • Apex SM-10
  • front: 18x9 in. ET46, ~21 lbs.
  • rear: 18x11 in. ET60, ~23.7 lbs.
  • 89.4 lbs. total
  • front tires: 245/40R18
  • rear tires: 295/35R18 or 305/35R18
  • Apex Notes:
    • We recommend a minimum of approximately 2 degrees of negative camber up front to keep the wheel/tire within the fender. This is the ideal fitment from a performance standpoint, as the wide 9-inch front wheels will provide superior tire sidewall support in comparison to the 8- and 8.5-inch front wheel options.

19-inch Option

  • Apex SM-10
  • front: 19x9 in. ET46, ~21 lbs.
  • rear: 19x11 in. ET60, ~23.5 lbs.
  • 89 lbs. total
  • 9 lbs. lighter than stock yet 1 in. wider up front.
  • front tires: 245/35R19
  • rear tires: 305/30R19
  • Apex Notes:
    • These fitments are a direct fit and do not require suspension/alignment modifications. These are the factory 997.1 GT3 tire sizes, which makes it a popular choice among C2/C2S owners

What about going wider in the rear? Another note from Apex: The brand also sells 12-inch-wide rear wheels in both 18- and 19-inch diameters for the 997 chassis, offering hardcore track enthusiasts and racers with maximum sidewall support.

After digesting all the options for our Porsche, we decided that switching from 19s to 18s would (hopefully) add some sidewall compliance–and thus comfort–to offset the move to a more track-focused tire. We also saw the move opening up tire options for our car.

We chose the Apex SM-10, a flow-formed model, in a classic silver finish: 18x8.5-inch fronts and 18x11-inch rears. The fronts currently retail for $434 each and the rears for $484 each, but we’ve seen Apex offer sale prices.

Image courtesy Apex Race Parts

The SM-10 delivers several motorsports-friendly features, including massive brake clearance, ample room around the lugs, and a knurled inner bead to keep tires from rotating on the rim.

These wheels also come hub-centric for our application, while the I-beam spokes help save weight and increase strength. The inner lip is reinforced for strength–a benefit of the flow-forming process. Apex also notes that these wheels carry JWL and VIA certification. And finally, they’ll accept the stock center cap.

 

Tires for Our Porsche 997

Now we needed tires–something appropriate for a day of lapping or autocross as well as the drive there. Today’s crop of 200tw tires seemed to fit that bill, with the fast and composed new Bridgestone Potenza RE-71RS sounding perfect for the mission.

Our own testing has shown that it’s a clear standout in today’s 200tw market.

[200-treadwear tire test | Bridgestone Potenza RE-71RS vs. Falken Azenis RT660]

For sizes, we followed Apex’s advice: 245/40R18 fronts and 295/35R18 rears. (To save you from scrolling to the top of the page, we started with 235/35R19 fronts and 295/30R19 rears.) The new Bridgestones cost about $250 for the fronts and $373 for the rears.

Despite the tire’s track-focused nature, we’ve found the Bridgestone RE-71RS to be surprisingly street-friendly–and perhaps some of that is thanks to the move from 19- to 18-inch sizes.

By installing wider front wheels along with sportier tires, we’ve increased our front-end grip, removed understeer and achieved sharper turn-in. Tire Rack’s reviewers have voiced similar findings with this tire.

We also shaved some rotational mass, improving acceleration, braking and handling. Going to the more aggressive package added only a pound to each front corner while shaving 5 from the rears:

  • stock 19-inch front tire wheel package: 41 lbs.
  • new 18-inch front tire wheel package: 42 lbs.
  • stock rear tire wheel package: 56 lbs.
  • new rear tire wheel package: 51 lbs.

The new setup is a winner on the street, but what about on track? We’ll have an update soon. Once we upgrade our brake pads, do a service and add some protection to our perfect original paint, we’ll be back out on track to give you a full report.

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Comments
kaybat
kaybat New Reader
12/6/22 1:25 p.m.

That fitment guide they have is handy(especially for someone that has no clue how to size tires) :-) It's a great starting point.

docwyte
docwyte PowerDork
12/6/22 2:49 p.m.

Not sure why you didn't go with the widest wheel possible for track use?  I'm personally using the Apex wheels in 9" front, 12" rear on my 996tt, very happy with them and they fit perfectly without rubbing.

Tim Suddard
Tim Suddard Publisher
12/6/22 4:41 p.m.

In reply to docwyte :

Trying real hard to keep this car truly streetable. The goal is to drive 500 miles comfortably to an event, do that event and then drive home. If I did drive, I would have to live with the track tires and wheels on the road. Took a 200 miles trip last week and they were fine for street use.

Tim Suddard
Tim Suddard Publisher
12/6/22 4:41 p.m.

In reply to kaybat :

I thought it was pretty handy too.

CAinCA
CAinCA GRM+ Memberand HalfDork
12/6/22 5:22 p.m.

I'm running the 9x18" and 10x18" SM-10 on my Cayman with 245/40/18 F and 275/40/18 R tires.  One word of caution. The Apex wheels have less offset than the stock wheels. After I added the GT3 arms and 16mm of shims my wheels wound up with a bit of poke. Thankfully they don't rub.

docwyte
docwyte PowerDork
12/7/22 10:02 a.m.

In reply to Tim Suddard :

Ok, but I still don't see how the wider wheels impact that?  Like I mentioned, they fit my car perfectly fine, with no rubbing at all.

350z247
350z247 Reader
12/9/22 10:19 a.m.

In reply to docwyte :

If they went with the 12 inch rear, they would just maintain the rear-biased grip they were trying to correct, and the 9 inch fronts require 2 degrees of negative camber to not rub which is going to eat tires. Their pick seems like a good compromise between practical and performance.

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
12/9/22 3:22 p.m.
docwyte said:

In reply to Tim Suddard :

Ok, but I still don't see how the wider wheels impact that?  Like I mentioned, they fit my car perfectly fine, with no rubbing at all.

Wider wheels means more tramlining, which could be a pain on the street, and possibly a slimmer selection of street-friendly tires.

(Wouldn't stop me though, I like wide tires and I cannot lie laugh)

docwyte
docwyte PowerDork
12/9/22 3:31 p.m.

I run the same width tires on 8, 8.5 and 9" wheels, same with the 11's and 12's.  Will a 245 tramline more on a 9" wheel vs a 8.5"?  Kinda doubt it.  Will a 9" wheel need 2 degrees of negative camber to fit?  Maybe, I run way more than that and can't say I see any aggressive tire wear on my car.  That being said, it's not a daily driver, so isn't seeing 10-15k miles a year.  My front tires do have close to 10k total miles on them tho and they're not all chewed up by camber wear. 

DWNSHFT
DWNSHFT Dork
8/22/23 8:23 p.m.

New wheels are better looking than the lobster claws.

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