guys with meaty tires and big power, 17x8 vs 18x9.5?
 

I have 2 sets of wheels, one set on the car and one set in the garage. Both sets look great so thats not a factor in choosing. I don't mind having 2 setups either, one for race and one for street or whatever.

Currently I am looking for more grip in the car. Its not terrible right now but it could be better. What setup would you run? I feel like the 18x9.5 would be the better option but I am not sure what size tires I can fit. I previously ran 265/35 squared on this setup but I am thinking of bumping up to maybe a 275 for the rear, I am not sure that would even fit?

What do you guys think? I would love to hear from guys who currently or had previously ran a fatter tire setup.

Car currently is 100% street driven but it is not a daily and will never be driven in rain unless I happen to just get caught outside in a storm. Also some possibilities in the future for track/strip days.

Rear tire would be a DR, no slicks.

Yes I'm aware of the meaty tire thread, I am browsing through it as we speak, its about doubled in size since I last was on here.

So basically 17x9 vs 18.9.5 and why?
What tire size and why?

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Currently on the car:
Gram lights 57dr - 17x9 +38
245/45/17 (front)
275/40/17 (rear)

Sitting in the garage:
RPF1's 18x9.5 +38
265/35/18 squared (currently, looking to replace)

Other information that might be useful:
ST coil overs
Verus engineering LCA's and camber plates
SPC toe arms

If you don't care about staying square, I'd go with a 10" rear wheel and a 295 if it'll fit (based on the DR and big power comments). I haven't done much checking about what offset would be needed and how much clearance you'd have going that wide, but with coilovers in the rear you should have room for a lot of tire.


That said, that much tire in a drag radial is probably going to make the rest of the driveline live a very short life.

I don’t mind leaving a squared setup but I already own 2 sets of wheels I don’t want to buy another set so I’m really trying to stay with the 17x9 or 18x9.5.

That is honestly one of my concerns axles and things like that wile hooking properly, it’s something I need to keep in mind.

Run the 18x9.5 squared, it's better because you can rotate your tires if for no other reason.

What tires were you running in 265 before? If it's not a daily you could run R comps and gain more grip over whatever you were running even in 265's. Pretty much 265's is about as wide as you can go on stock body with a +38 to +40 without major work and additionally you'd want to go wider wheel on anything over 275 as that's certainly flush on a 9.5".

One thing to consider about r comps (or even EHP 200 tw tires), they need heat to work. If you're not going to get them up to temperature, you're better off with a less grippy tire that works better at ambient temperatures.

I assume if they are looking for a tire that's going to hook harder they aren't talking about all seasons...any true summer tire should have no problem as long as it's 40+ outside. I never found my Star Specs or similar 200TW tires to need to heat up for grip unless it was sub 40 degree weather and even then they hooked pretty well given their size (275's)

Good to know, that is one of the things I was wondering was what the max I could go, so it sounds like I am already there.

So my setup before was RPF1's with conti DWS (all season) 265/35 squared.
That setup was on my old daily driven BRZ which was FBO with OFT stage 2, 93 oct tune. So that setup was more for comfort/looks but I still have the wheels and tires in the garage and i was thinking it may be better to throw a better tire on that setup and run those then the 17x9 I'm running now.

Interesting I will have to keep that into consideration when looking to replace tires. Im going to research hard into this aspect right now, thank you for the reply.

Yes I am not daily driving the car and I am not looking for all seasons. I live in Florida so its hot all the time, rain is a consideration. I have no plans on driving in the rain but sometimes you just get screwed and it comes out of nowhere.

Thank you for the replies.

just for some other background information...

My new setup is 17x9 squared (as stated before)
Fronts: Toyo R888 245/45/17
Rears: Nitto NT555r 275/40/17

The car is boosted and making over 500whp on e85.

I would like to grip a little better, first and second are useless and sometimes you can expect to sen at higher speeds/gears.


Part of me wants the grip and wants to have more usable power but also as stated by someone above I don't want to start breaking other parts either, although I almost never plan on launching the car. So that will have to be another decision I have to make.

EDIT: Double Post

Yeah so if you switched to something like Bridgestone Potenza RE-71R or Dunlop Direzza ZII which are (200 A A) over the Continental DWS (540 A A) on your 18x9.5 in 265's that would be a huge improvement. As far as the rain is concerned I can't speak personally for the Potenza but the Direzza handled the rain just fine. I dealt with colder temps than you will in DFW and plenty of rain without issue.

At that kind of power level I'd imagine you're eating rear tires more frequently than fronts so being able to rotate would help on cost if it matters to you. You'll never be able to hook in the low gears without one of three things 1) gear based boost control, this would be my recommended solution and is also easiest on drivetrain parts but may not be possible if you're on a blower and not a turbo setup and also dependent on your tuner 2) ET Streets which would be brutal on stock drivetrain if you're launching it hard, or 3) Functional widebody with some meats back there...I've seen people with 295-335 on functional widebody setups. Also those 3 solutions happen to be sorted least expensive to most expensive with functional widebody being a 5 figure investment all in.

EDIT: 4th option, regear to taller gears

Are you just trying to go straight or do you want it to handle too?

For my street setup I run 285/30/18 re71r’s on two different sets 18x10’s and 18x9.5’s both +40. The grip on the turns is awesome. Grip in 1st gear and second sometimes is iffy unless it’s a hot summer day and the tires are warm 3rd and up traction is not a problem

My experience was the 285/30 fit better than the 265/35.

Your offset at +38 might work but I can’t say.

I’m pushing 558rwhp btw

Nitto makes a 285/35r18 drag radial nt05r which is much better than the nt555r which really isn’t much of a drag radial by now days standards.

The 275/40/17 set up would be much better for straight line grip I would run either a Mickey Thompson or the Hoosier (which I have on a 17x9 +40) if you’re serious about actually getting it to hook in a straight line.

But yeah the stock driveline won’t like any kind of dead hooking

Gear based boost control is something i was thinking about not to long ago, ill have to see what my options are there with the tuner. I was also looking last night at regearing last night actually. At this point in time I am not looking to go wide body i prefer the stock body lines and look.

Honestly I care more about straight line right now. I will probably never autoX it and I would like it to grip for spirited driving but most of the cars driving will be street pulls, at some point I will start stripping it. So basically looking for straight line.

Are you talking like a MT et sweet SS or a slick, slicks are definitely out of the question unless its a decimated strip setup and I haven't gotten there yet.

I am planning on replacing rear axles and everything in the future just hoping not to snap something and be forced to do it prematurely.

My trans is solid and I'm running a CF driveshaft so right now my biggest concern is my rear end.

I want to look more into regearing and possibly some boost by gear option, but fr now i figured a good wheel tire combo would be the fastest/easiest option.

The tires aren't terrible and i know first gear will always be trash I'm just thinking that there is probably some better options or combinations out there which is why I asked this.

Drag radials like you were asking about. I’m running Hoosier dr2’s. It’s a drag radial with a wrinkle wall. The MT drag radial is a close second to the Hoosier dr2

Some say the wrinkle wall helps with the shock of the launch on a manual transmission car.

I just stalked your threads and your car is insane man. I love it.

Ok i will have to look into it. I have never been good with tires, this is the fastest cars I've owned right now so I've never really cared much or needed this level of grip.

EDIT: How do the hoosier stack up when not heated up? I need something that will perform well without really heating them up.

:lol:Thanks buddy! LMK if I can help.