285's all around? - NJFBOA - Home of New Jersey's Camaros and Firebirds

Mark42 · 02-26-2010, 02:49 PM

I see that 275 40 17 is a popular size for all 4 tires on F-bodies. Also see some references to the 285 40 17 is used too.

Can the 285 40 17 be used on front without rubbing? Would be using zr1 style wheel.

I prefer the 285 over the 275 becasue it is closer to the 26" wheel diameter so the speedo is nearly correct.

BonzoHansen · 02-26-2010, 02:52 PM

285/40/17 has allowable rim width range of 9.5-11" . Not sure if that is an issue for you, thought I'd mention it.

Featherburner · 02-26-2010, 05:11 PM

What size are on it stock?

Mark42 · 02-26-2010, 05:34 PM

Quote:

Originally Posted by Featherburner

What size are on it stock?

235 55 16 is the factory tire size on a base model coupe.

ib4200 · 02-26-2010, 06:14 PM

im pretty sure the 98-02 with the ls1's had 275-40-17's which would make 285-35-17 the plus size for them but im not sure if they'll fit

BonzoHansen · 02-26-2010, 06:55 PM

Is 285/35/17 even a real size you can buy?

Mark, one minor tidbit to note. Most decent tire places probably have a 275/40/17 on the shelf. 285/40/17 not so much. As a daily driver this might be a consideration.

ib4200 · 02-26-2010, 07:18 PM

well the middle number is a percent of the tire width so if you make the tire wider without changing the height of the tire, the middle number changes, a general rule of thumb is for every ten the first number increases, you take 5 away from the middle number

Mark42 · 02-26-2010, 07:25 PM

forget about 285 35 17, no one makes that size.

The size I read people using here is 285 40 17. Its nearly the same diameter as the 235 55 16. Maybe the ls1 has different pcm parameters for calculating speedo? Either the base model has an incorrect speedo, or the ls1 has an incorrect speedo, because 235 55 16 and 275 40 17 are about 1/2" difference in height.

BonzoHansen · 02-26-2010, 07:32 PM

Yes, the PCM can be recalibrated for tire size. Plus some people don't care about an ~1% speedo difference.

ib4200 I understand the math, it just ain't a real tire! Plus IIRC you add 1 to the rim size (thus the 'plus 1' moniker). So a 275/40/17 and a 285/35/18 are very close. A 285/35/17 is 3/4" shorter than 275/40/17. Edit: 285/35/18 does exist. A 315/35R17 is very close in OD to a 275/40/17, which is why that is a popular 'plus 0' sizing.

NastyEllEssWon · 02-27-2010, 04:18 AM

the difference in overall diameter would be 8 mm's more, which is just shy of 1/3 of an inch.

Blacdout96 · 02-27-2010, 08:19 AM

What type of rims are you looking to put these on?

creeper · 02-27-2010, 11:01 AM

285's will be fine all around. people run 315's in the front with no modification. they're recommended for a 9.5" or wider wheel, but the 285's going on my WS6 wheels are no wider than the 275 BFG DR's that are on them now so I'm not worried.

TheV6Guy · 02-27-2010, 02:17 PM

what kinda rims you gettin for the bird mark??

Mark42 · 02-27-2010, 10:20 PM

Quote:

Originally Posted by red99bird

what kinda rims you gettin for the bird mark??

Thinking of the ZR1 rims. They look close to the original rims on the bird.

andy78TA · 02-28-2010, 03:15 AM

I have 295s at all four corners on mine and I will say that steering is a little harder with the big front tires.

JL8Jeff · 02-28-2010, 11:14 AM

285's should be fine, I was thinking about switching to them as well. It might affect your gas mileage vs the 235 though with more tire hitting the ground for more rolling resistance. And wider tires are quite a bit worse in the winter.

TheV6Guy · 02-28-2010, 02:23 PM

Quote:

Originally Posted by Mark42

Thinking of the ZR1 rims. They look close to the original rims on the bird.

those will look pretty damn good on the bird. i wana get some nice ones for the redbird.but the but bumper come first to be fixed.haha

Slow-V6 · 03-01-2010, 09:55 AM

Quote:

Originally Posted by Mark42

Thinking of the ZR1 rims. They look close to the original rims on the bird.

If you want to get some 17's that look like your stock wheels then Check out the 98-01 1/2 WS6 wheels. Also for a cheap way to cal your speedo SLP sells or use to sell a Speedo Recal box that hooks into your wiring harness. I picked up mine for 25.00 on LS1 tech for my V6. Every time I went from 3.23,3.73, and 4.10 all I needed to do was turn a nob on the box to cal my speedo.

sweetbmxrider · 03-01-2010, 11:35 AM

for what its worth, the wider front tires "track" significantly. you will feel the car get into the groove of the road and want to stay with it. as far as tire model, i loved my firestone firehawk wide ovals. great on dry or wet pavement, never had them in the snow though.

Blacdout96 · 03-01-2010, 12:55 PM

as a fellow V6 owner that went with ZR1 Rep's, I have 275/315 on my car, you can feel the increase in rotational weight, in both acceleration, and braking. grip is nice untill you slip into the crown of the road where the semi's run lol. unless your seeing some kind of track time like auto-x or road racing, id suggest going 275 to free up a little rotational weight, and tire resistance. Also you havea larger tire selection with 275's.