OCD over tire size, help!
Thread Starter
Racer
Joined: Mar 2014
Posts: 409
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From: Taunton MA
OCD over tire size, help!
I am getting new tires for my '94 vert. I bought new 5 spoke ZR-1 replicas that are 17X9.5" 54mm offset.
I want to get the same tire on all 4 corners. Should I get 285/40 17 or 275/40 17???
I know the difference is a CM and the profile difference is even less than that...
Any insight into handling, look, ride would be greatly appreciated!
Thanks a million!
C
I want to get the same tire on all 4 corners. Should I get 285/40 17 or 275/40 17???
I know the difference is a CM and the profile difference is even less than that...
Any insight into handling, look, ride would be greatly appreciated!
Thanks a million!
C
Pro
Joined: Mar 2015
Posts: 574
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From: Windsor Va
As far as handling, if you do any "spirited" 
driving, the 285's will give you a little more grip. But as for the looks, the 2 sizes are so close that from 3 feet away,I don't think you could tell the difference. They're only 10mm wider and the sidewalls are 4mm taller. Why not have the shop mount one of each? Then you can decide by actually seeing them on the car.
driving, the 285's will give you a little more grip. But as for the looks, the 2 sizes are so close that from 3 feet away,I don't think you could tell the difference. They're only 10mm wider and the sidewalls are 4mm taller. Why not have the shop mount one of each? Then you can decide by actually seeing them on the car.
Team Owner
Joined: Sep 2003
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As far as handling, if you do any "spirited" driving, the 285's will give you a little more grip. But as for the looks, the 2 sizes are so close that from 3 feet away,I don't think you could tell the difference. They're only 10mm wider and the sidewalls are 4mm taller. Why not have the shop mount one of each? Then you can decide by actually seeing them on the car.
driving, the 285's will give you a little more grip. But as for the looks, the 2 sizes are so close that from 3 feet away,I don't think you could tell the difference. They're only 10mm wider and the sidewalls are 4mm taller. Why not have the shop mount one of each? Then you can decide by actually seeing them on the car.
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The 94 speedometer was calibrated for the 285 rear tire. The 275 tire may cause the speedo to read just slightly faster with the 275 tire. There should not be any fitment issue with a 285 tire in front.
AND AS MENTIONED, The only concern would be the future availability of the 285 tire. The 275 has a wider use so I would expect the 275 tire to be available from a variety of manufacturers for a longer period.
AND AS MENTIONED, The only concern would be the future availability of the 285 tire. The 275 has a wider use so I would expect the 275 tire to be available from a variety of manufacturers for a longer period.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
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From: South Dakota
I have run both sizes with no problems.
The 285 is 26" tall and the 275 is 25.7" tall so with the 275's the speedometer reading 60 you will only be doing 59.3 mph. For me that was close enough to not get me in trouble.
Currently I have all four 275's on my '95 now.
The 285 is 26" tall and the 275 is 25.7" tall so with the 275's the speedometer reading 60 you will only be doing 59.3 mph. For me that was close enough to not get me in trouble.
Currently I have all four 275's on my '95 now.
Race Director
Joined: Jan 2007
Posts: 14,935
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From: NYC NY
Just keep in mind that whether you go with 275s or 285s the actual size varies a bit from brand to brand.
Remember that picture of the 315 Goodyears stack next to the 315 Sumis?
The Sumis were noticeably narrower.
Remember that picture of the 315 Goodyears stack next to the 315 Sumis?
The Sumis were noticeably narrower.
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Pro
Joined: Apr 2004
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From: Texas
very true,these are both 285's
left is a Michelin and right is a Goodyear gsd3
I would venture to say the gsd3 is one of the widest tires you can get in whatever size.
Le Mans Master
Joined: Jun 2009
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From: South Dakota
It is not uniform that all tires from a manufacturer run wide or narrow. For example the 315 Sumitomo HTRZ runs small compared to several other brands, but the 255 Sumitomon HTRZ runs bigger than several other brands.
Generally I have also found that the Goodyear's run to the larger size and the Firestone's generally run to the smaller size.
Thread Starter
Racer
Joined: Mar 2014
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From: Taunton MA
Team Owner
Joined: Sep 2003
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For actual "fair comparison" each tire would need to be mounted to an identical wheel and then compared tread to tread (centered) standing up with the same air pressures. You could use a tire/rim caliper to measure the difference in the sidewall and divide in half to more accurately represent how it might appear on the car.
Last edited by WVZR-1; May 1, 2015 at 10:29 AM.
Le Mans Master
Joined: Jun 2009
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From: South Dakota
Actually I was thinking of the 255/45/17 late C4 front tires where the Sumi's were a wider than the Firestone's.
For 255/50/16 tires I have not tried Sumitomo, but the Falken ZE-512's were a lot narrower than the original Goodyear's from my '85.
For 255/50/16 tires I have not tried Sumitomo, but the Falken ZE-512's were a lot narrower than the original Goodyear's from my '85.