need help with tire descion??

[hurricanecris24]

so my front went out of aligment and both front tires are showing wires so i have to replace them. i have a set of 18s that i might as well put on and get all brand new tires.i dont know what size tire to get they have some 255/40 on them right now.

this is how the car sits. only the front is drop like a half inch or inch. i dont plan on lowering it so im not worried bout wheel gap i just want the best tire size for better traction it being front fwd and its my dd also

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[snowborder714]

How wide are the 18" wheels? This will be needed to help determine how wide of a tire you can get. If there's 225/40's on there now, my guess is either 18x7 or 18x7.5.

 

[hurricanecris24]

The ones on right now are 255/40. I don't understand what the numbers mean and also ill measure it when I can I got the rims for free and the person only knew that you were 18s

 

[snowborder714]

The 225 is the width of the tire in millimeters. The 40 is the aspect ratio. It means the height of the sidewall is 40% of the width (which is the 225).

You'll want to take a look on the back of the rim as it should say the width there.

 

[hurricanecris24]

Okay ill check it out. So what would you recommend? Wider tires?

 

[snowborder714]

I can't give a recommendation until I know the width.

As an overall recommendation, yes, I would recommend wider tires. Although 225's work fine for the street, if you plan on doing any form of racing, a wider tire would be a better choice.

 

[hurricanecris24]

There 18x7.5. Yeah I use it on the street and plan on taking it to the track.

 

[snowborder714]

Whoops, I read your posts wrong twice

There are 255/40 tires on a 7.5" wide wheel?? That is far from ideal. Actually, I'm not even sure how that would work. I run a 225/40 tire on my 18x7.5 wheel and probably wouldn't go any wider than a 235 wide tire.

 

[hurricanecris24]

Those are the numbers on the tires. My buddy that had them had it on his eclipse and they fit fine

 

[snowborder714]

I'd like to see some pictures of them, on and off the car if possible.

 

[hurricanecris24]

I would but I don't have the right size lug nuts. I need to order some so the wheels stay on

 

[snowborder714]

Well, I gave my opinion of not going any wider than a 235 tire, but the decision is up to you. I really can't imagine a 255 tire on a 7.5" wide wheel, especially when the smallest wheel to mate with a 255 tire is a 9" wide wheel.

 

[hurricanecris24]

Thanks for the input. I have another question can I get something different then the 40?

 

[snowborder714]

Were you looking to go shorter or taller?

 

[hurricanecris24]

what you mean by that? short tires?like the thickness of the tire?

 

[snowborder714]

Sidewall height. I explained what that was above.

 

[hurricanecris24]

okay sorry im a tard

 

[Guzman08]

run 225 by 40. . i have 18's . just be careful with the pot wholes. and those 255 probably wore out since they were to big. when u would turn they would touch the top . just dont go over any pot holes with the 18's or u will warp the rims.

 

[snowborder714]

I probably wouldn't go much more than a 40 AR tire unless I sat down and did the calculations to see if it'd fit. But a 40 would be a good size.

 

[knochgoon24]

A 245/40/17 has a good bit of clearance in the front with a +38 offset 8" wide rim. I wouldn't think that an extra 1/2" wide section width or 3/8" taller radius would cause too much of a problem. The offset on the rims would have to be right though. And you ARE going to to stick out of the front fenders.

EDIT: Actually, I just plugged the numbers into a tire size calculator. The height should fit, just it's going to be close to the knuckle without the correct offset.

I also just noticed that you're talking about putting them on front and back. It's all going to come down to offset as to whether they fit.

 

[snowborder714]

You do realize we're talking about a set of 18's he's getting, don't you Wes?

 

[knochgoon24]

Yeah. I do. I took that into consideration.

Tire Size Calculator - tire & wheel plus sizing

Use this then compare what you get to your current clearances. Just factor in the difference in offset.

 

[snowborder714]

Doh, totally missed the point that you were using the Star Specs as a reference.

Were you just trying to say his 255 tire will work fine? If so, won't there be any sort of issues in relation to mounting?

 

[knochgoon24]

I don't think a 255 on a 7.5" rim would be any worse than a 225 on the stock rim like some do. The sidewalls will stick out from the tires (almost 1.25" on each side). Handling won't be as good as if you had a proper sized rim.

If you hit a large bump, your fenders will hit the tires unless the fenders have been rolled. They'll probably need massaged out some, not just the lip rolled.

We need to know the offset of the rims. That's the big thing.

The mustang guys like to fit 255 on 7.5" rims.

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This shows 275 on 8" rims on the front and 335 on 10.5" rims on the back. The tire hangs out past the rim 1.41" and 1.34", respectively.

A 255 on a 7.5" rim will stick out pas the rim about 1.26".

 

[hurricanecris24]

okay i dont know the offset but heres a pic of the tires. the one on the left is 235 and the right is 255.
<a href="http://s737.photobucket.com/albums/xx16/hurricanecris24/Mobile%20Uploads/?action=view&current=IMG00017-20100503-1054.jpg" target="_blank"><img src="http://i737.photobucket.com/albums/xx16/hurricanecris24/Mobile%20Uploads/IMG00017-20100503-1054.jpg" border="0" alt="Photobucket"></a>