SportCoupe2

What would the ideal tire size be for the following wheels on a '93 RX7, all stock suspension?

front 18x9, 44mm backspacing
rear 18x10, 44mm backspacing

Second question, what would the maximum width tire sizes be for the same wheels?


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purerx7

iTrader: (61)

i run 285/30 out back with out any rubbing or any problems, i have wide front fenders so cant help you out on the front, this is on a +46 wheel as well.

SportCoupe2

bump for more input please.

Trout2

iTrader: (5)

Not sure if you can run them with +44 offset but ideal is 255/35 and 285/30 (closest to rolling diameter of the original 225/50/16).

Jack

ptrhahn

iTrader: (9)

Try 275/35/18 rear, and 255/35/18 front.

The only problem with the 285/30 rear is that's much shorter than a 255/35, and I wouldn't really want a taller front to rear tire. It looks funny, and is going the wrong way as far as the rake of the car... so you'd really want no more that a 245/35 up front.

Here's an example of 275/255... same rim sizes, but +42 offset.

SportCoupe2

So the maximum front tire would be 255/35 and maximum rear would be 285/35 (slightly taller then the front)?

I have two very nice BFG KDW2 265/35 tires, would it be possible to run them on the front with fender rolling? I believe they may be too narrow for the rear 18x10 wheels.

Has anyone run a 295/35 in the rear on an 18x10 +44 offset?

ptrhahn

iTrader: (9)

275 is the largest you should go with a 35 series. 285 and higher need to be 30 series (remember, the series is a percentage, not a fixed height). A 295/30 is around the same height as a 255/35, but is a little too wide for a 10" rim.

You can do the 285/30, 255/35 combo, just know that the rear tire will look lower profile than the front... which personall, I don't like.

unicorn_squad

265/35 will fit on a 10 no problem. recommended width for that size tire is 9-10.5.

then just run like a 245 in front.

cabaynes

iTrader: (4)

I run 285/30 in the rear and 255/30 up front with 18x9 +43 and 18x10 +43... When you have the wheels off the car you can see that the rear tires are about half an inch shorter than the fronts, but on the car you really can't tell any difference. Here is a pic:

ptrhahn

iTrader: (9)

^^^^

Looks better than I would've thought Charlie... maybe I'll do 285's next time :-)

SportCoupe2

If my 265/35 will work up front that would be ideal for me, then I'd just have to buy a set of 285/something for the rear.

I can't test fit right now because my FD is on jackstands getting work done.

gnx7

iTrader: (10)

For the street..... the 255/35/18 front and 275/35/18 rear is a great combo. They are also probably the cheapest cost for tires in that size. I ran them on my last FD.

Going to a 285/30/18 nearly doubles the price of the tire.....

SportCoupe2

I'd like to use my two 265/35-18 tires if possible. Can I run them on the front or do I have to run them on the rear?

What other size tire should I get that would go with these two 265/35's?

cabaynes

iTrader: (4)

the 265 will be pushing it for the front wheels, especially if you don't have a roll/pull on your front fenders. You could get some 255/35 tires for the front wheels, and throw the 265's on the rear and then upgrade to 285's when the 265's wear out... You *should* wear them out much faster than the fronts, so the 255's you get now would probably still be in good shape when you replace the rears.

cabaynes

iTrader: (4)

Well thank you! I don't have any closer pics but the sidewall isn't as short as you'd think, and that slight bulge of the tire past the wheel lip looks very aggressive from the rear

Trout2

iTrader: (5)

I know about the difference in height b/t the 255/35 and 285/30 on paper but it has never caught my eye on my own car.

darkslide750

I was looking at some 285's vs 275's and saw this thread.
Size Diameter Sidewall
285/30/18 - 24.7in 3.4in
275/35/18- 25.6in 3.8in
255/35/18- 25.0in 3.5in
265/35/18- 25.3in 3.7in
255/30/18- 24.0in 3.0in

AntiVenom7

there is plenty of room in the back for a 285-35 if you wanna run it(depending on your how low you are), but the overall diameter is about an 1 larger than stock. not a big deal in my opinion, but others will disagree. a larger tire actually helps put power to the ground from take off(both the larger diameter, and somewhat more forgiving sidewall), but "hurts" you one the top end. it'll also give you ever so slightly better gas mileage, the amount is negligible, for the most part.

the difference in overall diameter of the a 275 to a 285 both in 35series is gonna be 3/10"
http://www.miata.net/garage/tirecalc.html

SportCoupe2

OK, I ended up using the 265/35-18 in front. I had to cut the lip off, not just roll it. In the rear I am using the 295/35-18 tires that came with my slightly used WedsSports from a forum member. I'll say I might have got away with just a fender roll in the rrar as well I ended up cutting the rear lip off too just like the front. Here's a good pic.

AntiVenom7

^^^^what's the offset?

SportCoupe2

You must have skipped the very first post. Offsets all around are +44mm.

unicorn_squad

holy crap those tires look HUGE... how much power are you running that you need those monsters?

cabaynes

iTrader: (4)

you bastard, i wanted to buy those wheels.

cabaynes

iTrader: (4)

and those 295's look wayyy too big. Switch to some 285/30's

AntiVenom7

no, i read it but didn't look at the poster's name. i am sure we have all done dumber things in life.