Hey guys,

Needed some quick advice. I am placing an order for a set of wheels and tires. Getting a set of hankooks with the following fit: (recommended)

225 - 40 - 18

255 - 35 - 19


If for whatever reason I wanted to switch that fit with the following:

225 - 40 - 18

275 - 30 - 19


In my uninformed opinion, the wider tire will look better and therefore I am happy to go with it. Is there any reason why I should not? Will this work? Any advice or recommendations is much appreciated. The car is not lowered. Everything is stock at the moment.


Thanks,

FJP

 

FWIW, I think the profile diff between F and R, 40-30 is too great, makes it look a bit out of place. My plan is 235/40/18 F, 285/35-19 R, and my NA is completely stock too.

 

I run stock in the front and 285/30/19 rear with no issues other than hearing that @ 60mph I'm actually traveling at 61.2. If that's an issue just go 80mph.

I found that it's also easier to find winter tires in that size.

 

Running stock fronts with 285X30X19 rears for over 2 years. Because it is a wider tire, sidewall heght is almost identical to the stock 255X35X19.

 

Does anyone know if the 285/30-19s work with a lowered car and 15mm spacers without sticking out past the fenders?

 

SRT SIX is right.
A 225 width tire and a ratio of 40 is 90.00 mm sidewall height.
A 235 width tire and a ratio of 40 is 94.00 mm sidewall height.
A 275 width tire and a ratio of 30 is 82.50 mm sidewall height
A 275 width tire and a ratio of 35 is 96.25 mm sidewall height.
A 285 width tire and a ratio of 35 is 99.75 mm sidewall height
A 285 width tire and a ratio of 30 is 85.50 mm sidewall height

OP, have you tried using this tool:

https://www.crossfireforum.org/forum...ment-tool.html

It will help you see what fits.

 

that last though is almost a 10MM diff between the fronts and the back, and I think that's too great. the 275's then are just about 2 mm diff, but the 285's/35 are only 6 off.

 

mdaniels-

I didn't even calculate the tire size the OP asked about- look again!

 

Totally agree. The set mdaniels recommends is perfect to maintain the 18/19 staggered look, and vouch that the 30 aspect ratio in the rear will look odd. Been there, done that ... they simply do not fill out the wheel well with respect and in proportion to the 40's up front.

Note that 235/40R18 and 285/35R19 is the absolute largest tire combination to be safely installed on OEM rims, sans fooling around with spacers. Any fatter up front and the tire will conflict with the control arm nut. Ouch. And it is not recommended that a rear tire wider than 285 be mounted on the OEM width rim. Even 285 is a bit of a stretch, so you may want to settle on 275.

Good luck and enjoy the ride.

 

Kane is absolutely right. Should be stickied, took me an hour or two to find this info.

"Note that 235/40R18 and 285/35R19 is the absolute largest tire combination to be safely installed on OEM rims, sans fooling around with spacers"

 

yes you may be right about that overall, Kane. perhaps the 235/40 F and the 275/35 R may be better or better overall. With this ratio you get 94 mm sidewalls in front, 96.25 in the rears vs 99.75 if you go 285/35's in back. So they'd probably fill the well just fine, and look even between the two.

The issue I'd see with the larger ones at the edge of the wheel safety margin is that it's stuffed onto the wheel, and let's say at speed you're pushing hard in the corner and stressing the bead, there's a distinct possibility of it popping off. Not good. But probably wouldn't happen.

 

Thank you guys for the help. Looks like the information adds up.

Successfully placed the order.

Went with the 285 - 30 - 19's for the rear.

I hope SRT-six's comments apply for the 2004 Crossfire Limited as well.


Thanks again,

FJP

 

Does anyone else concur this statement?

Is there any possibility that a rear fitting of "285 - 30 - 19" could cause the tire to "pop" off the wheel?

If you are a spirited driver and have more than once exercised the max speed of the vehicle, would you be at risk? (SPECIFICALLY because of the specs of the tires stated)

Thanks,

FJP

 

Do not run a 285 on a STOCK rim...I run a 305 30 19 on 19x11 rear wheel! 285 and 295 should have at least a 9.5 or 10 inch rear wheel!!!

 

Hate to say it gents, but I feel that you're looking at the wrong variable.

In order to maintain the original staggered wheel proportions, you shouldn't necessarily be focusing on the relative sidewall heights, but moreso on the overall tire diameters. When looking to fill out the wheel well in the same staggered proportion as the OEM tires, it's the diameter that counts.

So if you change the front tire to, say, 235/40R18, you want to look for a rear tire that is taller by the closest overall amount so that the wheel wells are filled out proportionately. Use the fitment guide link above and do the work with a little spreadsheet. You'll find that running a 30 aspect ratio in the rear fails to maintain proportion.

I'd show you the results, but doing it yourself might be the only acceptable demonstration. Does that make sense? The best solution is 275/35R19.

 

Agreed. Like I mentioned above, running 285mm on OEM rear rims is technically OK, but it's right on the edge and a real 'stretch' on a 9" rim. Best to back down to 275 if you're going to drive like a maniac.

285/30-19

285 mm (11.2'')

86 mm (3.4'')

655 mm (25.8'')

19x9 to 19x10.5 Suggested rim width

2057 mm (81'')

782.5

 

Kane,

Any knowledge about going slightly wider on the fronts? Anything to gain here? I heard wider tires in the front hurt handling slightly and it's only recommended going 235 from 225 for aesthetics and nothing else. True or false?

 

I doubt if anyone (me, anyway) could tell the difference in Handling, but 235 look a bit better than those puny 225's. Wish we could go wider without using spacers. So I guess the answer is 'True'.

 

Attached is a section of a file I keep for all my cars. Use it to track accurate fuel mileage & operating costs for each vehicle.

 

Used the tool mentioned by Maxichon https://www.crossfireforum.org/forum/...ment-tool.html

255x35x19 deliver 10" tread width x 26" overal tire height x 3.5" wall height

275x35x19 deliver 10.8" tread width x 26.6" overall tire height x 3.8" wall height

285x30x19 deliver 11.2" tread width x 25.8" overall tire height x 3.4" wall height

I researched this heavily before buying replacement tires around 3 years ago. I was assured that the stock rear width would handle the 285's, but not to go larger.

Over two years later multiple track days, slalom events and the 4500 mile cross country trip from the west coast to CAA in St Louis last summer and no issues with bead "pop". I would classify that as aggressive driving.

Just because a tire has specific ratings, does not mean they all fit or stand the same. Each brand (and model within the brand) "lays" on the road differently. My first set of 285x30x19s were Nitto Invos. they looked like street slicks and had a very soft compound (wore out extremely fast). The sidewall did stretch over the rim a fraction (it actually helped prevent some rim rash). My Hankook Evo 112s are more flush with the rim and curv in at the top not quite as vertical as the Nittos.

However, when running the recommended 36 pound of pressure in the Invos, the tires had way too much sidewall flex as a result I generally ran 40 lbs all around. Funny thing is that if overinflated, the center should have worn first, they did not, it was the edges. Also, I don't know if it was the softer compound but the outside edge of the front tires showed excessive feathering.

The Hankooks have twice the milage (and more to go) and are running with 36 lbs with smooth wear across the tires.

Back to the original point. the 285x30 has a wall size of 3.4" vs the stock 255x35 at 3.5" I dont think I can even notice .1". However going to the 275X35 with a wall height of 3.8" a difference of .3" would certainly be noticeable AND measurable.

These are just my observations, everyone has to make their own decisions.