kisik

Please help/educate me. I just received my new NT01 set for my 997 C2S.
When I measured the total width with my calipers I was really confused.

235/40-18: Width = 248-250 mm (9.8"). Spec calls out for 9.49"
305/35-18: Width = 320-322 mm (12.6"). Spec calls out for 12.32"

They are truly running wider by about 10mm then comparable 235 and 305 with Michelin and Yokogama. Some people say: well, consider you have 245/315 set and paid for 235/305. But I was thinking running 8" front and 11" rear and now probably need 8.5-9" front and 12" rear to make it more squire fitting.
I called Nitto without any explanations. DOT is 5214.

Thoughts??

Thank you for sharing. Perhaps someone could measure at least roughly.

TXE36

The NT-01s run just a bit wide, at least in the size I'm familiar with 235/40-17.

The Nitto web site specifies the recommended rim width.

I've seen other tires that are much worse, Hankook RS-3s run really wide. 245/40-17s are wider than Nitto NT-05 255/40-17s.

-Mike

Bill Verburg

ANy tire measures differently depending on the wheel width,

rule of thumb, .5" of extra wheel width adds ~ .2" to the tire section width

obviously the tread width is not changed

per Nitto 235/40 x18 mounted on an 8.5" wheels will have a section width of ~9.49" a wider or narrower wheel will provide a different result

305/35 on an 11" is ~12.32"

stownsen914

Also, it's hard to tell if the OP is measuring mounted or unmounted tires. Simply mounting a tire changes it's dimensions.

kisik

I think I understand more. Correct me if I am wrong here. What I was measuring was a section width of unmounted tires was irrelevant.
What important is a section width in relation to a wheel size upon that tire is mounted. Just like Bill was saying, my 235/40-18 NT01 will "shrunk" to 9.49" with 8.5" or to 9.29 with 8" rim.

Since tread width is not changing here, what are the real life advantages going to wider rim?
So why everybody likes to have wider rims for more squire fitting with say 9" rim for 245 and 12" for 305? Avoid rolling, stiffer sidewalls?

Martin S.

...to hear that Nitto NT-01 are a bit wider, maybe 10mm. This is what Tire Rack told me about the new Hoosier R7. The don't have R7 in 285 yet, but 275 are close to 285...so I ordered a set. That was just before I made a 100% conversion to Nitto NT-01 tires.

33% cheaper and last 2 to 3 time longer....not quite as fast, but when the cost per cycle is considered...just drive better is the solution!

Bill Verburg

Regardless of the wheel width the tire has the same amount of material in it.

The wider wheel stretches the tire more putting the sidewall in greater tension leaving less room for flex, the narrower the wheel the the less tension and more flex.

oe's usually use the narrowest wheel they can because it is cheaper and the car ride is plusher due to the flexing sidewalls

for max performance you want to tension the sidewall as much as possible to eliminate flex, so you use the widest wheel that you can fit.