Nitto tire width vs wheel width clarification
06-11-2015, 08:18 PM
#1
Nitto tire width vs wheel width clarification
Background: I have a 997.2 4S which infected me with the trackday bug. I want to go for R compound tires and need some clarification on tires and wheels. Not looking for brand recommendations in this post. Plan on keeping suspension stock but might get more aggressive on camber much later on.
Tires:
The tire I am looking at is the Nitto NT01. On their website they have a column heading “Approved Rim (Measuring Rim) Width” and then for the 235/40ZR18 tire for example the info is “8.0-(8.5)-9.5”. I assume they are saying the tire will fit rim widths between 8.0 and 9.5. But what is the value in parenthesis? SeeNT01 Description
Wheels:
The tires I expect to run are 235/40ZR18 front and 305/35ZR18 rears. Because of the AWD I am matching front to back diameter ratios as closely as I can to the stock setup. The tire widths match my current street tire setup.
My stock wheels are 8x19 and 11x19. I plan to get an 18 inch set for track only use and for me ugly+cheap beats pretty+expensive so looking at used older Porsche sets. I will be using stock calipers and 18s are listed as a winter setup so I don’t expect clearance issues.
Regarding offsets on the 18s, the offset calculators I am looking at show that if I keep the same tire widths as the 19s then offsets won’t need to change- even if I change wheel width? I understand there might be performance value in messing with track width via offsets but I want to keep it simple. Is there a ballpark close enough offset difference, for example if my current offset is 51 then +/- 5 would likely be OK but +/-15 is asking for trouble? Since this is a track setup I want to avoid spacers. Thanks.
Tires:
The tire I am looking at is the Nitto NT01. On their website they have a column heading “Approved Rim (Measuring Rim) Width” and then for the 235/40ZR18 tire for example the info is “8.0-(8.5)-9.5”. I assume they are saying the tire will fit rim widths between 8.0 and 9.5. But what is the value in parenthesis? SeeNT01 Description
Wheels:
The tires I expect to run are 235/40ZR18 front and 305/35ZR18 rears. Because of the AWD I am matching front to back diameter ratios as closely as I can to the stock setup. The tire widths match my current street tire setup.
My stock wheels are 8x19 and 11x19. I plan to get an 18 inch set for track only use and for me ugly+cheap beats pretty+expensive so looking at used older Porsche sets. I will be using stock calipers and 18s are listed as a winter setup so I don’t expect clearance issues.
Regarding offsets on the 18s, the offset calculators I am looking at show that if I keep the same tire widths as the 19s then offsets won’t need to change- even if I change wheel width? I understand there might be performance value in messing with track width via offsets but I want to keep it simple. Is there a ballpark close enough offset difference, for example if my current offset is 51 then +/- 5 would likely be OK but +/-15 is asking for trouble? Since this is a track setup I want to avoid spacers. Thanks.
06-16-2015, 12:50 PM
#2
Contacted Nitto. Their answer impacts both my tire and wheel question. The numbers “8.0-(8.5)-9.5” indicate the min to max wheel widths the tire is acceptable to fit on. The number in parenthesis is the ideal wheel width, but also the the wheel the tire was mounted on when they do measurements on the tire section width.
According to Tire Rack explanation the tire section width will change based on mounted wheel width, a change of 0.2 inches tire width change for every 1/2 inch wheel width change.
According to Tire Rack explanation the tire section width will change based on mounted wheel width, a change of 0.2 inches tire width change for every 1/2 inch wheel width change.
06-20-2015, 02:30 AM
#3
To maximize tire grip and feel, generally you want a wheel width a little wider than the tread width.
That being said, cheap set of stock 8s and 11s will be fine. A lot of people run cheap OZs. I think theyre 8.5 and 11s. Should fit fine with no spacers but spacers are perfectly fine for track use too. Just use a reputable brand and torque properly.
That being said, cheap set of stock 8s and 11s will be fine. A lot of people run cheap OZs. I think theyre 8.5 and 11s. Should fit fine with no spacers but spacers are perfectly fine for track use too. Just use a reputable brand and torque properly.
06-20-2015, 05:21 PM
#4
Rennlist Member
There is a perfect set 8x11" from C4 that I run on my C2S: Carrera III. Perfect fit for 235/305 NT01 combo. Fantastic tire. If you have any questions please ask me.
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997 C2S 05'
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997 C2S 05'
