Got new rear tires, but now its hideous

[spederman]

Tire sizes are confusing me and screwing me. I thought i knew what i was doing, but obviously not, my car is stupid looking now. I have 255/35/18 pirelli p zero nero ms in the fronts and had the same in the back but 265/35/18's. I decided i was going to get some replica 18x10's and then run nice wide tires so i can hook up. Well, thats exactly what i did. I got BFG KD's in 285/30/18. Well, these new tires are SOOOO low profile and thin side wall compared to the 255/35/18's in front. I put them on my car, and stepped back to look at it and . The rear tires are so thin that the gap between the fender and tire is huge. But that's not even the bad part, the car looks really bizaare with the front tires being 35 series and having a taller side wall. They have a huge side wall compared to the side wall of the rear and it looks seriously dumb. Kinda like i have donuts in the rear and normal tires on the fronts. WTF should i do? I'm so confused and pissed off. what a waste of money. Any suggestions?

 

[Dope 97GT]

well I had just the opposite problem with my car I bought the 18x9 and 18x10 saleens and put 255/40/18s in the front and 285/40/18s in the back and the tires in the rear looked huge and pretty dumb as well.

What I did was take the loss and put the 285/40s on ebay and bought some used goodyear 295/35/18s off of ebay for 220 shipped.

I wish I woulda just did a burnout with them and video taped it and just bought some new ones.

You can maybe sell them on ebay or somethin or maybe try to sell them on here but If you want to change them you pretty much have to take the loss like I did.

 

[Mustang5L5]

http://www.miata.net/garage/tirecalcold.html

There's a pretty good tire size calc.

Stock 245/45/17's are 25.6" in diameter

255/35/18's are 25" in diameter
265/35/18's are 25.3" in diameter.


So both your sizes are slightly short.


A 275/35/18 would give you a 25.6" diameter. It would be a pretty good match front and rear. You can play around with that tire calc to figure out good sizes

 

[BlackenedSVT]

In case you dont know:

The way tires are read are like this: 255/35/18 meaning the tires are 255mm wide. The 35 means the sidewall is 35% of the overall width. So the sidewall is 35% of 255mm. And the 18 is obviously the wheel size.

When you buy tires, you want the overall dimensions of the wheel (hieght wise) to be equal for every wheel. So your first set up of 255/35/18s in the front and 265/35/18s in the rear are mismatched. 35% of 355 is 89.25. So your front tire sidewall is 89mm thick. And your rear of 265/35/18 is (265x35%=?) 92.75. So the rear sidewall is 92.75 thick. As you can see this is a mismatch and your rear tires are actually thicker and raising the back of the car 2.5mm about. Now while this isn't a HUGE difference in mismatching, sometimes it can throw off yoru speedo. You really want to make the tires sizes as close as you can.

So now lets see your new setup. 255/35/18 is the same 89.25 wide of sidewall in the front. And your new rear of: 285/30/18 is 85.5mm wide in the rear. So as you can see your rear IS in fact smaller than your front...which explains the wierd look you might have. Because its almost 4mm smaller in size.

If you are going to run a 255/35/18 up front. You really should run a 305/30/18 in the rear which would equal 91mm wide sidewall. Which is a little closer to beint equal with your front wheels. Plus the 305 will be a lot wider.

I realize you might know all this info already. But i thought i'd share it with you anyway, in case you didn't know

And i know your 18 inch wheels really restrict your tire options, as many companies dont make wide 18" wheels/tires. I would recommend some 275/40/18s (equallying 110mm sidewall) for the front with some 315/35/18s for the rear (also equalling a 110mm sidewall)

 

[spederman]

I was on that tire calc site looking up the specs from my old 265/35/18's and my new 285/30/18's, they are only 1/2 inch off in diameter and the sidewall is only 0.3 inches smaller on the new 285's. But they sure dont look 0.3 inches off, they look like they are 3 inches difference. Plus that calc said that my rear tires are only 0.1 inches smaller side wall than the front, but there is no way that can be right according to how it looks.

I was thinking maybe i would just get some lower profile front tires, but they dont make any 255/30/18 or 265/30/18's. The smallest side wall ratio in those two sizes are 35 series, so that does me no good.

The only other thing i was thinking was getting rid of the rear's on ebay and get the BFG KDW2 in 295/35/18's. But how do i know if that will even be the right size side wall. What if i go through all this crap and end up with the same situation.

 

[spederman]

In case you dont know:

The way tires are read are like this: 255/35/18 meaning the tires are 255mm wide. The 35 means the sidewall is 35% of the overall width. So the sidewall is 35% of 255mm. And the 18 is obviously the wheel size.

When you buy tires, you want the overall dimensions of the wheel (hieght wise) to be equal for every wheel. So your first set up of 255/35/18s in the front and 265/35/18s in the rear are mismatched. 35% of 355 is 89.25. So your front tire sidewall is 89mm thick. And your rear of 265/35/18 is (265x35%=?) 92.75. So the rear sidewall is 92.75 thick. As you can see this is a mismatch and your rear tires are actually thicker and raising the back of the car 2.5mm about. Now while this isn't a HUGE difference in mismatching, sometimes it can throw off yoru speedo. You really want to make the tires sizes as close as you can.

So now lets see your new setup. 255/35/18 is the same 89.25 wide of sidewall in the front. And your new rear of: 285/30/18 is 85.5mm wide in the rear. So as you can see your rear IS in fact smaller than your front...which explains the wierd look you might have. Because its almost 4mm smaller in size.

If you are going to run a 255/35/18 up front. You really should run a 305/30/18 in the rear which would equal 91mm wide sidewall. Which is a little closer to beint equal with your front wheels. Plus the 305 will be a lot wider.

I realize you might know all this info already. But i thought i'd share it with you anyway, in case you didn't know

And i know your 18 inch wheels really restrict your tire options, as many companies dont make wide 18" wheels/tires. I would recommend some 275/40/18s (equallying 110mm sidewall) for the front with some 315/35/18s for the rear (also equalling a 110mm sidewall)

Thanks for that info. I knew it was a ratio, but didnt know how to calculate it to get actual dimensions of the side wall. It does make more sense. I guess i dont know which tires to swap out to match, the front or rears. It sucks that there arent very many size choices when you get into the 18's and going really wide. Then they also get outrageously expensive. Also, i knew about the speedo getting off, but that doesnt make a difference for me since i have an XCAL 2 and can easily punch in my new tire size and recalibrate the speedo.

 

[Dope 97GT]

look on any factory saleen and see the tires they come with 265/35/18 and 295/35/18s in the rear. Heres the linkhttp://www.saleen.com/SC101_Services/SC101_Shopper/showItem.php?menuId=104&itemNum=023-265

with these sizes you will get the look you are going for. Just look on a stock saleen with like 1000 miles on ebay they all have the pirelli stock tires on still

 

[Nick03gt]

look on any factory saleen and see the tires they come with 265/35/18 and 295/35/18s in the rear. Heres the linkhttp://www.saleen.com/SC101_Services/SC101_Shopper/showItem.php?menuId=104&itemNum=023-265

with these sizes you will get the look you are going for. Just look on a stock saleen with like 1000 miles on ebay they all have the pirelli stock tires on still

that is the perfect size tire for 18" rims IMO

 

[spederman]

yeah, you guys are right, i have been crunching all the numbers for every possible tire size. And the absolute perfect would be 295/30/18 but since there are hardly any tires that come in that size for a decent price, that wont work. I guess it will have to be 295/35/18's. Thats the next closest match. And they make BFG KDW2's in that size for $229 at tirerack.com. But as my luck goes, backordered.

Man, i wish i would have known this before i bought the tires that i got. What a freaking waste of cash. Anybody want to buy a brand new set of BFG KD's 285/30/18's?

 

[BlackenedSVT]

Oh keep in mind the STOCK tire size is 245/45/17 (equalling a 110mm sidewall), and this tire sits i think 25" in total diameter. If you get an 18" wheel like you have a run a larger tire size, and the wheel & tire are then larger than i think 25" you may run into some rubbing problems.

Just wanted to give you a heads up. Basically you want to "plus" size the tires for the 18" wheel, but keep it as close to stock as you can. Don't want any rubbing issues.

there are TONS of threads on rubbing issues for 18" tires. So if you do a search, im sure you can find what kind of tire sizes people are running on their 18s.

 

[wms004]

Tire sizes are confusing me and screwing me. I thought i knew what i was doing, but obviously not, my car is stupid looking now. I have 255/35/18 pirelli p zero nero ms in the fronts and had the same in the back but 265/35/18's. I decided i was going to get some replica 18x10's and then run nice wide tires so i can hook up. Well, thats exactly what i did. I got BFG KD's in 285/30/18. Well, these new tires are SOOOO low profile and thin side wall compared to the 255/35/18's in front. I put them on my car, and stepped back to look at it and . The rear tires are so thin that the gap between the fender and tire is huge. But that's not even the bad part, the car looks really bizaare with the front tires being 35 series and having a taller side wall. They have a huge side wall compared to the side wall of the rear and it looks seriously dumb. Kinda like i have donuts in the rear and normal tires on the fronts. WTF should i do? I'm so confused and pissed off. what a waste of money. Any suggestions?

285/35/18 would have been the ticket. If you go to www.tirerack.com and click on a tire, and then specs, it shows exactly how tall the tire is. You want something betwen 25.6-26" for the rear.