best tire sizes for 17x8 and 18x9 wheels

[skyline23]

Hi guys,

I am going to be buying new tires soon, and wanted to know what you guys think is the optimal tire size combo for my wheels:

Front: 17x8 +48 (currently have 215/40/17)
Rear: 18x9 +30 (currently have 245/40/18)

I'd like as wide a tire as possible with no rubbing or traction control issues as I track the car (don't want r compounds, most likely will get ad08s or dunlup star specs). The car is lowered about an inch..

anyway, any input would be awesome,thanks in advance!

 

[TURBO2GO]

Edit: correction by Ken

265/35/18 pre-94
255/35/18 post 94

 

[skyline23]

265/35/18 pre-02.
255/35/18 post 02

Thanks, my car is a 91 so looks like you recommend 265/35/18. And this would this work with my current front tire size?

 

[TURBO2GO]

Thanks, my car is a 91 so looks like you recommend 265/35/18. And this would this work with my current front tire size?

Yes.

 

[nsxtasy]

Make that:

265/35-18 for '91-93 NSX
255/35-18 for '94-05 NSX

 

[skyline23]

awesome, exactly what I was looking for..thanks guys!

 

[06_typeS]

Is it just me or am I reading it wrong. He is looking for tire reccomendations for a 17" front wheel. And everyone is telling him to put an 18" tire on????

My advice is if your running an 17x8" front wheel. Go with a 225/45 or 40/17 in the front.

*EDIT* Re-read thread and notice that it was the rear tires that were being reccomended. Im sooo blonde.

 

[TURBO2GO]

Is it just me or am I reading it wrong. He is looking for tire reccomendations for a 17" front wheel. And everyone is telling him to put an 18" tire on????

My advice is if your running an 17x8" front wheel. Go with a 225/45 or 40/17 in the front.

*EDIT* Re-read thread and notice that it was the rear tires that were being reccomended. Im sooo blonde.

LOL... not only are you blonde but your front tire recommendation of 225/45 would rub like a pair of size 6 jeans on Sofia Vergara's ass.

 

[06_typeS]

Really??? I didnt think it would rub at all. Although I was just basing my opinion on whats on my RSX.

 

[NSX-Barque]

Sofia Vergara's ass?

 

[JDMFreak]

Well im running a 225/45/17 on my front wit stock height and no fender lining.. No rub..

 

[nsxtasy]

Well im running a 225/45/17 on my front witH stock height and no fender lining.. No rub..

When you remove the fender/wheel well liner, you create more clearance, but you risk the tires picking up small stones from the pavement and causing "reverse dings" on the fenders.

 

[TURBO2GO]

When you remove the fender/wheel well liner, you create more clearance, but you risk the tires picking up small stones from the pavement and causing "reverse dings" on the fenders.

And some ugliness in the wheel well.

 

[scammy]

I have had 225's on the front and they rub the inside of the wheel well they destroyed my fender liners when i lowered it with Eibachs springs.
215's as recommended for the front is the only safe option

 

[NYCNSX]

Just out of curiosity why do you guys suggest a wider rear tire on a 91-93 than a 94-05?

 

[TURBO2GO]

Just out of curiosity why do you guys suggest a wider rear tire on a 91-93 than a 94-05?

Either will probably be ok, but assuming 215/40 is up front, which is the largest "safe" size up front, a 255 rear keeps the closest F/R "ratio" to OEM on 1994-2005 cars. That means the traction control system sees the front and rear wheels spinning about the same as what it was calibrated to see stock. On 1994 and older cars, that OEM ratio is different, as they used different sized tires OEM and a 265 or even a 275 keeps that front/rear ratio closer to OEM when you've switched from the 15" front to a 215/40/17 front.

There is some disagreement on what the traction control modules of various years were tuned to see as correct and to not intervene. Ken says there is an error in the parts book regarding numbers, happa88 has said several times he feels there is not. You can search and follow the threads. But it mainly has to do with TCS. I am one of the few that runs a 255 rear, same as my OEM size, with 215 fronts. Most people tend to go for a 265 rear even on post 1994 cars, mainly for a look, and also for the fact that on a 10" wheel which many opt for, a 255 would start to look really stretched. A 265 already has a mild stretch.

If you change to a larger front tire, like a 235, then you want to go wider rear, to like a 275. For example 1K2Go chose this path. There is slight rubbing on almost anything wider than the 215. When you go with more rubber, there are some benefits but also some drawbacks including weight, cost, noise, and ride quality. You have to also consider the fact that your suspension is generally tuned to handle a particular track width, a certain weight of the wheel and tire combo, etc. if you veer too far off OEM, then your suspension must also be off OEM. 1K2Go tells me my 255 rear is too "puny", and I have a lot of respect for him, but I disagree with the use of his sizes being better than my sizes for my NSX especially for street tires. For the track, slicks and R comps may be a different story. But for a car that is street driven, I feel a 215/255 on a post 1994 car is a better more performance oriented solution.

Hope all that wasn't confusing. I am sure I just fanned the flame on this thread. LOL

 

[nsxtasy]

Yes, that's correct. To be more concise: The TCS operates based on the difference in outer diameter between the front tires and the rear tires. The '91-93 cars had smaller-diameter front tires (but not rear tires) than the '94-05 cars, so when you use larger-diameter fronts on those cars, you need a slightly larger-diameter rear tire than the later cars need.

There is some disagreement on what the traction control modules of various years were tuned to see as correct and to not intervene. Ken says there is an error in the parts book regarding numbers, happa88 has said several times he feels there is not.

Even if there is not an error in the parts book, the only year in question is '94, and only for the manual-transmission cars. Automatic-transmission '94 cars used a different TCS calibration from '93, and on manual-transmission cars, the '95 TCS is different from '93. The only question is what was used on the '94 manual cars.

So the '95-05 cars (and the '94 automatics) need sizes with a slightly larger rear (or slightly smaller front) than the '91-93 cars. It's just not clear which sizes are best for the '94 manuals.

 

[MrHugo]

I have a set of 17x8 +38 and 18x9.5 +40 CE28s.

My car is going to have a 1.5" to 2" drop, and I am thinking of getting 215/40/17 and 265/20/17.

But when I was looking at these 215 on the 17x8, they look stretch. I have been told that 235/40/17 will rub on 17x8 +38 at the front if lowered 2", but only on full lock. Is it safe to run 235 than? If 235 in front, i want to run 275 in the rear.

So should I go 215 front and 265 rear, or 235 F, and 275 R. 2" drop with about 2 deg camber front and 3.5 camber rear.

Thanks

 

[scammy]

in case you were wondering what a 225 can do to fender liners with a 1.5 drop

 

[nsxtasy]

I have a set of 17x8 +38 and 18x9.5 +40 CE28s.

My car is going to have a 1.5" to 2" drop, and I am thinking of getting 215/40/17 and 265/20/17.

There are two problems with that idea:

1. There is no such thing as a 265/20-17 tire on the market.
2. If there were a 265/20-17 tire on the market, it would be impossible to mount it on an 18x9.5 wheel.

:biggrin:

 

[MrHugo]

There are two problems with that idea:

1. There is no such thing as a 265/20-17 tire on the market.
2. If there were a 265/20-17 tire on the market, it would be impossible to mount it on an 18x9.5 wheel.

:biggrin:

Hey, Smarty pants. Its 265/40/17 Ok?!!? Gosh... lol

 

[nsxtasy]

Hey, Smarty pants. Its 265/40/17 Ok?!!? Gosh... lol

You're not going to be able to mount a 265/40-17 tire on an 18x9.5 wheel, either! :biggrin:

 

[TURBO2GO]

Hugo put down the red bull brother I think you've had a few too many. LOL

- - - Updated - - -

You need a 215/40/17 front and a 265/35/18 rear with much less negative camber. Depending on if you track or not. I'd say -1.5 front and -2 to -2.5 rear. What you're talking about is for very aggressive track setups. You will have no tire life.

 

[MrHugo]

You're not going to be able to mount a 265/40-17 tire on an 18x9.5 wheel, either! :biggrin:

haha, I give up...

^so 215 and 265 huh? I was really looking to be 235 and 275, but i guess I should go the safe route.

 

[TURBO2GO]

haha, I give up...

^so 215 and 265 huh? I was really looking to be 235 and 275, but i guess I should go the safe route.

You're going to rub with a 235. What is the point? you aren't going to get more traction per the size, you will just make it all heavier. If you go to the track a lot and need an R comp and that only comes in a 235 then you can run it but soon as you go full lock you will rub. This info is already plastered over this site. 215/40/17 front. 255/35/18 rear if your car is a 1995 or newer car, 265/35/18 if the car is 1991-1994. I am Ken's parrot now. If your rear wheel is 9-9.5 wide, the ideal is the 255. If it is 10" wide, then the 265. So some of this is based on wheel availability and ownership but ideal is a 255 on 1995 and newer cars. If you need more grip for some reason you go to a stickier tire not a bigger tire. Keep weight down. Your suspension performs better, you get better response, less rotating mass.