Hey guys, I have a question for everyone who has tried this set up, specifically the rears! I talked to a guy at Tirerack.com who left a bad taste in my mouth about this setup. I wanted to go with a 255/45/18 rear all seasons with 245/40/18 fronts. I know this topic has already been mentioned in this forum but I've seen very little actual content about how this setup performs and feels. The guy at tirerack.com said I would basically neuter the car because the rear tires would roll under the rim while cornering. I'm not looking for super performance here, but I don't want the rear to feel like its floating or squishy. I was a little surprised that he would say that considering it is only a little wider than stock. Could someone who actually has this setup please comment on their experience!
Thanks!
Jeff

 

The 245/40 - 255/45/18 combo should work quite well. The car will handle in a more neutral fashion (not so much understeer), and the factory stagger will remain. Since both the fronts and rears are 8" wide, the tires will fit quite nicely. There should be no issue.

Lou

 

Agree with Lou. I don't have direct experience with that set-up but I know someone who does in some pilot a/s sports. He's hasn't had any problems.

255 is ideally matched up with a 9" wheel but it'll do on an 8" It didn't look like it bulged at all either.

 

I have this setup but on a 18x8.5 rims, the stock I believe is 18x8 but I think it will work out fine..

 

From the last two posters- was it an improvement. Did it help reduce the understeer of the stock set-up? I wouldn't do it just to spend more money on tires for looks, but what was the resultant change in performance?


Cheers,
Derek

DB

 

I have had this set up for 3 months on stock rims. Pilot Sport A/S. I really like it. I didn't ever drive hard enough to slide the front tires before buy I have plenty of confidence that the car will handle nuetral now. I'm not autocrossing or anything, but it feels just fine to me. The only negative is that the steering seems to be not as crisp, or have less feed back, but I after a week I didn't notice it anymore. When I run these tires down I'm going to get another set just like them.

 

I ran this setup as well and it worked GREAT! 245/40 front and 255/45 rears on stock 18's! It all but eliminates the understeer (which was VERY welcome) and adds a beefier look to the car in general. It helps fill the wheel well in the rear, but I would swear you could not tell a difference in the front from the side, but obviously it is wider! I would NEVER go back to 225/245 ever if I still had stock 18's. Here is a pic on black stock 18's

'03.5 G Coupe, 6 speed, Bose, Nav, Ivory Pearl / Graphite, Bat's inlays, Short ram intake, Axis Millano 19's staggered, Tien H-Tech springs!

383802-IMG_0072.jpg

 

so to people who are running 245/255...
do you guys don't experience any problems at all??
like such as bulge/bubble/whatever(i don't know the technical terms)? cuz i don't want any possible problems with 255 on the rear...

 

I did A LOT of research before switching......I cannot come up with one negative issue, I would have not done it if that was the case! Your speedo will be off a touch, here are the details FYI:

Your speedo will be 1.3% too slow runnning 255/45/18's as opposed to 245/45/18. When your speedo reads 60pmh, you will actually be travelling 60.8mph

'03.5 G Coupe, 6 speed, Bose, Nav, Ivory Pearl / Graphite, Bat's inlays, Short ram intake, Axis Millano 19's staggered, Tien H-Tech springs!

 

Roadracer: How do you come up with the 1.3% ?

255/45/18 makes 771 revs per miles
245/45/18 makes 680 revs per miles

Therefore, according to the spec posted on Tirerack, there is a 91 revs difference. 91/680 x 100 = 13%.

If that is correct, then when the speedo reads 60, he would be going 68mph. Correct?

 

No

245/45/18 is 780 Revs Per Mile
255/45/18 is 772 Revs Per Mile

Difference is 8 Revs per mile or 1.025%

Your numbers are wrong.

Lou

 

The 255 will turn fewer times than the 245 because it is larger in diameter, all be it minor! It is true that different brands has minor differences in dimensions within the same size. That calculation came from this website ( http://www.miata.net/garage/tirecalc.html )and gives you a general rule of what to expect. This difference is SOOO little, it will not mess with the VDC, which is VERY important!

'03.5 G Coupe, 6 speed, Bose, Nav, Ivory Pearl / Graphite, Bat's inlays, Short ram intake, Axis Millano 19's staggered, Tien H-Tech springs!

 

roadracer

I wasn't disputing you - You'r numbers are correct. I was disputing Pat. I don't know where his numbers came from.

Lou

 

No worries bro, I was not thiking you were disputing me!

'03.5 G Coupe, 6 speed, Bose, Nav, Ivory Pearl / Graphite, Bat's inlays, Short ram intake, Axis Millano 19's staggered, Tien H-Tech springs!