DD tires for R

[Tomster]

I ran Bridgestone RE-11's 305/325 on 6GR's on my 2016 GT350R with zero issues.

[MENTION=7192]garagelogic[/MENTION]

Which lug nuts did you use for this setup? I have a set of 6gr R spec wheels laying around and want to get the carbon fiber wheels off the car ASAP. Thanks!

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[nastang87xx]

It's not the width that concerns me as much as the sidewall and overall tire height. Since changing down to 315/30R19 Hankooks on a 19x11" square setup, my R scrapes more. I can imagine that 305s would make that even worse. There's no way I'd go lower... just my $0.03.

You're not dreaming but it very much depends. Tire measurements from manufacturer to manufacturer are about as consistent as big news media on controversial issues. Prime example, 245 Hoosiers being "245mm wide". Lol yeah, right. They handily out measure 255 PZeros.

Unfortunately nowadays sometimes it's kind of a crapshoot on how wide and tall a tire really is. My 305 RS3 v2's and 305 RE71R's are actually almost bang on in real measurement with a tape measure and a comparison measurement side by side.

 

[Darkane]

I can also confirm PS4s dominate in width.

The 305 is much wider than the equivalent in cup2 or MPSS.

I'm running 305/325 on R-spec P51 wheels and there is some poke, but everything fits well.

First pic is 305 PS4 vs 295 MPSS fronts. As you can see the PS4 are over an inch wider give or take a mm.

They should only be 10mm wider lol. My ride height dropped just a touch 1/4" or so. Looks more in the pic but isn't.

 

[Davey]

I am so lost with all these tires. I do want a different tire for my car with the carbon fiber wheels. I want a tire that will keep the car at the same height. A direct replacement . What size do I need. Or can someone post a couple size and brand for direct replacements too keep ride height and bulging the same. I just want to stop throwing the rocks up as I do not track the car.

 

[J_Maher_AMG]

I can also confirm PS4s dominate in width.

The 305 is much wider than the equivalent in cup2 or MPSS.

I'm running 305/325 on R-spec P51 wheels and there is some poke, but everything fits well.

First pic is 305 PS4 vs 295 MPSS fronts. As you can see the PS4 are over an inch wider give or take a mm.

They should only be 10mm wider lol. My ride height dropped just a touch 1/4" or so. Looks more in the pic but isn't.

Actually they are only wider when comparing the PS4S to the GT350 specific MPSS. The "specific" MPSS for the GT350 are VERY narrow, i.e the shoulders are well rounded to offer better daily driving / wet driving characteristics.

Actual tread width measurements from Tire rack (i.e contact patch width):

GT350 specific MPSS:
295/35/19 - 10.0"
305/35/19 - 10.7"

GT350R specific Cup 2's:
305/30/19 - 11.0"
315/30/19 - 11.7"

So for just a "10mm" increase, the R's tires are a full inch wider on both front and back (25.4mm).

Now for the MP4S:
305/30/19 - 11.5"
325/30/19 - 12.2"

Standard MPSS:
305/30/19 - 11.7"
325/30/19 - 12.1"

So yes the tires appear wider than what you are taking off the car, but it is only because the OEM GT350 tires are very rounded and narrow for their size. The standard Super Sports are actually marginally larger overall compared to the MP4S in a 305/325 30 series fitment. The difference with the regular MPSS and MP4s is that they are much more square in how they fit on a wheel.

 

[J_Maher_AMG]

I am so lost with all these tires. I do want a different tire for my car with the carbon fiber wheels. I want a tire that will keep the car at the same height. A direct replacement . What size do I need. Or can someone post a couple size and brand for direct replacements too keep ride height and bulging the same. I just want to stop throwing the rocks up as I do not track the car.

You just need a 305/325 in a MP4S or any other tire to have essentially the same ride height (actually slightly more in the rear, but overall negligible).

The only tire you have to be careful about ordering is the Michelin Pilot Super Sport, as there are GT350 specific versions, as well as the regular variant, and the sizing in terms of width differs dramatically as I just pointed out. Height wise though, 305/325 in any brand and you'll be fine.

 

[machsmith]

You just need a 305/325 in a MP4S or any other tire to have essentially the same ride height (actually slightly more in the rear, but overall negligible).

The only tire you have to be careful about ordering is the Michelin Pilot Super Sport, as there are GT350 specific versions, as well as the regular variant, and the sizing in terms of width differs dramatically as I just pointed out. Height wise though, 305/325 in any brand and you'll be fine.

Isnt a 315 coming for the rears soon, in MP4S?
Im waiting for the stock set up.... hope it comes soon.

 

[Paul@PKAUTODESIGN]

305/30/19
325/30/19

Mpss
Mps4s
Conti extreme contact sport
Bridgestone potentate re-11


All very popular choices for Dd driving

 

[Davey]

Thanks. I hate to change the tires but the rocks can be bad at times.

 

[snaproll]

So, seems like a pilot sport 4S would be a good choice in a 305 30 19 for a rotatable R setup? Nice footprint. Anyone with experience or pics on the Project wheels?

Other than style, I just don't see the need to buy two different size tires and wheels for street or track unless understeer is your game.

 

[RadBOSS]

My PS4s are working perfectly in a 305 squared setup.

Remember the 305 PS4 is as wide if not slightly wider than the 315 Cup 2. It also weighs right about the same as the 315 Cup 2. If you're looking for a more stock staggered sizing with roughly OEM weight and stretch in the PS4S, do a 295/30F and 305/30R.

Not surprising as the 325 section width spec is only 10 mm (0.39") wider than the 315 (or less than 0.2" per side)

 

[J_Maher_AMG]

I'm unclear of what you're unsure of.

I put 305/30/19 PS4S onto 19/11 Forgelines.

Those 305/30/19 PS4S are taller tires than the 305/30/19 and 315/30/19 Cup 2s.

My ride height raised by roughly a 1/4" with that change. The PS4S in 305/30/19 is a wider and taller tire than the 315/30/19 Cup 2, and certainly wider than the 305/30/19 Cup 2.

It's easy to see where the ride height raised in the front from the different tire since the tire in the front OEM, is the 305/30/19 Cup 2 on a 19/11 wheel.

It is actually narrower than the Cup 2; see my post above concerning widths. And on the same wheel width, it won't be any taller... if you put it on a narrower wheel, i.e put a 305 on a 10.5" wheel and an 11.0" wheel, it may be slightly taller on the narrower wheel, but largely negligible.

And the PS4S are roughly between 16-20% heavier per corner, which is about 4-5lbs per tire. Have looked at many different tires and none comes close to the Cup 2's in terms of weight.

 

[AndreiD]

305/30/19
325/30/19

Mpss
Mps4s
Conti extreme contact sport
Bridgestone potentate re-11


All very popular choices for Dd driving

Hi,

Will doese sizes keep the same overall height as stock? What about for a normal GT350 (non R)?

I'm asking for a set of Forglines, and can't make up my mind for the tire. I don't want to run into lowering the car or offset the speedo reading...

 

[AndreiD]

It is actually narrower than the Cup 2; see my post above concerning widths. And on the same wheel width, it won't be any taller... if you put it on a narrower wheel, i.e put a 305 on a 10.5" wheel and an 11.0" wheel, it may be slightly taller on the narrower wheel, but largely negligible.

And the PS4S are roughly between 16-20% heavier per corner, which is about 4-5lbs per tire. Have looked at many different tires and none comes close to the Cup 2's in terms of weight.

I'm so confused right now... :lol: So widths in mm is not the same for each tire right? 305 on a tire is different than 305 on another :doh: WTF?! I thought mm is mm and just a unit of measurement and 305 a specific number? How can that vary?

Anyhow, what can one do to keep roughly the same height for a GT350 (non R)? Going 305 and upwards on 19x11 rims but on 30 sidewall in all configs loweres the sidewall and thus the wheel height.

 

[J_Maher_AMG]

Hi,

Will doese sizes keep the same overall height as stock? What about for a normal GT350 (non R)?

I'm asking for a set of Forglines, and can't make up my mind for the tire. I don't want to run into lowering the car or offset the speedo reading...

A 305/30 tire will be the same height as another 305/30 on the same width wheel... what happens is when you change wheel widths, is you can either "bulge" or "stretch" the fitment of the tires, causing a slightly increase or reduction to the sidewall height due to how the tire fits on the wheel.

So if you are using the same size wheels as stock, then yes they will retain the exact same height.

If want to keep the same ride height with a non-R, you just need 295/35's and 305/35's, same as stock. Otherwise you will lose height going to a 30 series tires unless you run something ridiculously wide.. you would need a 345/30 to get the same height as a 295/35.

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