AudiOn19s

I really like Toyo RA-1's and would like to run them for DE's but they don't offer standard 996 sizing. I'd either have to run 245 / 275 or 245 / 305...the later of these two being "better" in my mind as it keeps the proper spread front to rear for the car.

I'm wondering if the 305/35/18 on a factory 18 x 10 et 65 wheel will fit under the rear of a narrow body car. Toyo's tend to run small and a 10' wheel is within wheel width spectrum for these tires but I want to make sure they'll fit under the car without rubbing

Again this will be a DE setup only not daily driving.

Andy

BrockPorsche

Wow that's a giant tire. That's getting near Z06 territory!

Sorry, nothing constructive to add :P

AudiOn19s

I agree...and ideally it's not the tire size I want to run but I really like the Toyo's compared to the other r-compounds I've used.

exlondoner

With the correct offset you should have no problems running 305's out back and 245's up front.

I'm currently running 245 and 295 out back.

rbjbbb

Here is the compare at 1010tires compare tool. Unless you seriously went bigger up front or raise the profile to 45 up front, you have a big increase in circumference (assuming your comparing stock 265/35/18 like I have on my car. Looks like due to sign. increase width, you would have to roll the fenders to clear (hopefully that would be enough).
I am looking at tires myself. I have a lowered car and best I can tell, I can go 1" wider and the rim will be flush with outer rear fender (widest point). I am probably going 275/30/19 on a 10.5 rim and this put me about 2/3" wider (due to lesser offset on the wheels I am looking at)

(this is 265/35/18 vs 305/35/18 vs 245/40/18)

Stock Tire - 265/35R18 >Search Tires Tire 1 - 305/35R18 >Search Tires Tire 2 - 245/40R18 >Search Tires
Section Width: 10.43 in 265 mm
Section Width: 12.00 in 305 mm
Section Width: 9.64 in 245 mm

Rim Diameter: 18 in 457.2 mm
Rim Diameter: 18 in 457.2 mm
Rim Diameter: 18 in 457.2 mm

Rim Width Range: 9 - 10.5 in
Rim Width Range: 10 - 12 in
Rim Width Range: 8 - 9.5 in

Overall Diameter: 25.30 in 642.62 mm
Overall Diameter: 26.40 in 670.56 mm
Overall Diameter: 25.71 in 653.03 mm

Sidewall Height: 3.65 in 92.71 mm
Sidewall Height: 4.20 in 106.68 mm
Sidewall Height: 3.85 in 97.79 mm

Radius: 12.65 in 321.31 mm
Radius: 13.20 in 335.28 mm
Radius: 12.85 in 326.39 mm

Circumference: 79.48 in 2018.7 mm
Circumference: 82.93 in 2106.4 mm
Circumference: 80.77 in 2051.5 mm

Revs per Mile: 822.1
Revs per Mile: 787.8
Revs per Mile: 809.0

Actual Speed: 60 mph 100 km/h
Speedometer1: 57.4 mph 95.8 km/h
Speedometer1: 59.0 mph 98.4 km/h

Speedometer Difference: - Speedometer Difference: 4.353% too slow Speedometer Difference: 1.619% too slow
Diameter Difference: - Diameter Difference: 4.17% Diameter Difference: 1.6%


RB.

AudiOn19s

The 305 is pretty tall. I may just end up running the 245/ 275 combo...the 996's in Grand Am Cup were restricted to this sizing...I'm sure I could make it work.

That or I'll suck it up and just use a different tire again.

996CABOVA

You can run 305 in the rears of the Narrowbody. I was gonna run 305 with Pirelli Rosso but Im getting 315 in the rear now. It all depends of the offset of the rims.

jetskied

The 35 hieght might be too tall. I run 315/25/19 so the width is fine. I would look if they make a 30 series in 305/18. Personally the 295/30 would be your best bet.

10 GT3

First, although Toyo shows it will fit; a 305 is too wide of a tIre for a 10" wheel. Your section width is 12.1". You could easily get rubbing from sidewall flex in corners. Keep in mind that a 285 and a 305 on the same size wheel have the same amount of contact patch area with the same tire pressure. This means to gain contract patch you have to reduce tire pressure. Because you are overtiring the wheel, you actually have to increase pressure to decrease sidewall flex for stability so you will actually have less grip than running the smaller tire. The only way to gain grip is to go to a wider wheel that can use these tires effectively. Keep in mind Porsche by comparison puts a 305 on the rear of the new GT3 on a 12" wheel and the C4S on a 11.0-11.5" wheel.

The next issue is that these tires are incredibly heavy at 32 lbs. The extra rotational weight is going to slow acceleration and work your brakes harder.

The height issue will follow. I hope you don't have your car lowered or it can essily rub on bumps. This tire is 1.3" taller than the stock rear tires. This isn't a problem in a 997' that uses a taller rear tire, but a 996 is a different story.

The RA-1 is not the best track tire. It is a good compromise if you are looking for a tire for both autocrosses and DEs. It has less grip than Kumho 710s or Hoosiers in Autocrosses and MPSCs or Corsas at the track. They do tend to have good tread life, but on a hot track can still wear faster than MPSCs or Corsas.

For DE's I run a set of 18x9.0" wheels up front with 235/40-18 MPSCs and 18x11.0" wheels out back with 295/30-18 MPSCs. This is very similar to the setup a lot of the GT3s are running. We have a couple locally with full monoball conversions that are able to run 315/30-18's on 12" wheels. These setups are extremely well balanced with little sidewall flex (quick turn in), great stability, grip and a large contract patch with very low tire pressures.

Ed Newman

It will fit with the right offset, suspension and aligmnent. This does not mean it will fit on your car on the stock rim, more likely than not, it won't work. I run 245-40-18 front and 315-30-18 rear. Properly configured I believe I can fit the 275-35-18 in front and 335-30-18 in the rear. This would require the right offset wheels, small diameter coilovers, lots of nagative camber, cup front control arms to move the wheel back 0.5" and rolling the fender lips.

Porsche_Smile

i have 295 right now... i don't see why the 305 wouldn't fit... but everyone is right ... you need the right offset... stock won't do it....

LVDell

Actually it has NOTHING to do with offset. You already have the correct offset established for your wheel. What you need to be MOST concerned with in this instance is the rolling/inflated diamter of the tire. It is in fact too tall to fit. One of the guys over on the GT3 board as well as in the Racing/DE board have commented on this tire. It rubs since yuou are adding over an FULL INCH of diameter by moving from a 30 series tire to a 35 series tire. You need to move back to the 30 series tire. What are your options? If you like the Toyo, try the Nitto NT01. I have put them on my GT3 and they fit since they are within .3" of diamter to the 295/30 PS2 tire. The Nitto though only comes in the 315/30 size if you wanted to "go large". In this case you NEED an 11" rim which the 305-315 tire fits best on. Grab a set of GT3 wheels or you need to stick with the 285 or 295 tire on the 10" rim.

JimB

And the biggest reason of all not to use the 305/35 is that the height (even if it does fit) will effectively decrease (increase?) your final drive ratio causing the car to accelerate slower. Add the weight of the tire and you're screwed.

The other thing is to go fast you have to be able to steer the back of a 996 with the throttle. You can do that easily with a smaller tire. With a 305 or 315 you have to be pushing the car pretty hard. If you are still learning the car I would either go with the 275 or a 286-295 in another brand.

Just my 2 cents.
Jim