285/40/18 on 18x9s or 18x10s
 

I'd like to know if anyone ever ran
285 40 18s on 18" Mustang rims?

I recently picked up a 07 Monte SS the
factory rims are ok, but in my eyes just
bland & boring, for fun I put on a set of
17x9s Bullets I think it looks decent buthttps://cimg5.ibsrv.net/gimg/monteca...a65f30e087.jpg
https://cimg1.ibsrv.net/gimg/monteca...df55827896.jpg

I'd like to know if 18x9.5 (+/-) 285s fit.

I'd be careful with going too narrow a wheel with a 285. Many of the manufacturers I've seen have a minimum reccomended rim width of 9.5" for a 285.

Just curious, why a 285? Just seems like a bit of am oddball size given all the options for a 275.

285/40s are close to factory size, only .25" shorter.

The wheels would probably be 9.5" to 10" wide.

Concerned about the speedo? A 275/40 is a little further off in height, but the difference is negligible on the speedo, maybe 1 mph or so at highway speed.

It would actually be 3.5 mph difference because of height.

But for my 07 SS its my DD&MPG car. Theoretically having
a smaller diameter tire would give me better acceleration
but I'd be spining a lil faster on the highway eating more gas.

Yes it's probably a minimal amount but I'd rather be closer
to factory diameter. I've actually noticed that a 295/40/18
is the same height, but it's a pretty Wide Tire 295 s on all 4
corners would look pretty sick in my eyes. Need feedback.

Looking at tiresize.com's comparison of a 235/50 vs 275/40, it shows a 1.5 mph difference at 70.

Honestly, I wouldn't get too hung up on gas mileage though. No doubt a slightly shorter setup will change the gearing a bit, but you're talking about adding 2 inches of rim and 50mm of tire per corner. I'd bet you'll end up adding some notable rotational mass unless you get a really light wheel.