Hey guys i decided to purchase the 03 cobra chrome for my black 02 gt and was wondering what size 17 or 18 could someone help me out and tell me the advantages and disadvantages of having 18" rims on the stang would it cause any problems besides obviously weighing more and the tire costing more..

 

bigger rims slow you down...

 

While i agree i would make one note for those of you who might not totaly get the whole weight and rotating mass thing. If you add a larger rim that weights more yes you will go slower but if the rim weights the same or less then you will be the same or better performance wise.

So in most cases yes you will go slower, but wheels such as the 18" weld xp's or kong 18" rims these weight a ton less then stock and will make you go faster.

So to recap more rotating weight will make you go slower, less will make you faster as the car works less hard to move the mass.

But like i said overall in most cases a 18'" rim will weight more than a 17"



With that said i would get a 17" rim.

 

yea i cant decide either...either i go with 18" saleen or some 17" wheel

 

also tires are alot more money for 18" rims too think about that.

 

and wouldnt 17s be better because you can get them wider? or am i totally wrong?...

 

If you talking about deepdishing it. you can deep dish 18's as well but going back to the whole weight issue DD do weigh more. I do think 17's are better for performance

 

yea but doesnt the 17x10.5 help cause of the width? or drrrrr im retarded?

 

Yes the 17x10.5 is wider than the 18x10.

 

well yea 10.5 to 10, but isnt the width HELP your car at all? when i get tires n rims, prolly gonna do 17s cause lighter, and cheaper...and still have nice rims ;D

 

It helps you on traction yes.........but then again weight is still added so you win a little in one area but in the other ehhhh

 

hmm true... i dunno though

 

The weight of a deep dish or 10" wheel ofsets any performance gain you might get from it traction wise. Me i wouldnt go any bigger then 17x9 on the back and keep the stock fronts. But i am not like alot of guys.

 

I dunno.... I can see a car with 315's on the back getting a much better takeoff than a car with....say 275's. All depends upon what kind of power the car makes. But still a car with 315's on the back has a much larger contact patch. Forget weight when it comes to contact patches. The wider wheels are just GONNA get more traction. In the corners more than anything but its still gonna beat a stock car off the line. The unsprung weight that is added can also be relieved by the addition of lighter brakes or even lighter tires. If you have heavy wheels.....you can find some really lightweight tires. Theyre not all the same weight.

 

a dd wheel weights a ton. its deffinatly offsets any gain you might have becuase it has ot move so much extra wheel.

 

What he said....

 

:banana: I'll 2nd that!

 

I agree with this but I just want to add in something else:
1.) The height of your rim+tire is a factor because it dictates how far your car travels with each revolution of the spindle. If you've got stock gears and a really tall wheel/tire height, it's gonna kill your accelleration because it's effectively like sticking an even lower gear in there.

2.) Rotational Inertial. This has to do with both weight and distance. The more weight you have farther from the spindel, the harder it is to spin the wheel. So contrary to the information above, a 17 inch wheel and 18 inch wheel of the same exact weight will not perform the same. Since much of the weight is centered around the lip, especially in wide rims, there is more rotational intertia making the wheel effectively harder to rotate and thus requires more torque to accellerate at the same rate.

As a general rule, you want to pick the smallest, lightest wheel that will fit over your brakes, allow a nice wide tire, and not brake or crack under harsh conditions.

Since going fast isn't everything for everyone, there are other things to consider: 18 inch wheels cost more but more importantly, 18 inch wheels require significantly more expensive tires. They ride a bit harsher, especially with really low profile tires.

On the other hand, if the 18s are light enough, they'll still be much better than heavier 17s for speed. They'll fit over any set of brakes. They'll fill in the wheel well better. They generally look better. If all other things were somehow equal (rotational interia, etc..), they might handle slightly better on smooth pavement.

When it comes to width, wider tires = larger contact patch = better grip on dry pavement. BUT, they cost more. They tend to pull in the direction of the grooves in the road more. They may be worse in rain/snow/ice. You'll feel more road bumps. However, they really do look much better and they don't leave an overhang from the fender.

 

When That 150 Shot hits the ground............ I don't think DD's will matter.

 

18's all the way... ya maybe they slow you down a bit but nothing that i can notice at least.... with 18's you can run a thinner wall tire which in my experiences in auto-x is way better for corners.... plue the looks of 18's over 17's...

 

I used to be all about racing and performance.
After spending most of my paychecks on tickets and working on my car every weekend I decided to focus on having a nice reliable ride. With that said, I add mods that won't affect the reliability of the car like cold air intake, grill delete, suspension, etc. Hell, with as much as the population has grown here in California and the high cost of tickets and fuel, IMO it just isn't worth focusing on performance. I couldn't go fast if I wanted to with all the traffic day in and day out.. Not to mention all these people that shouldn't even have a drivers license pulling in front of you around every corner. I am considering 18 inch wheels.. But I'm not sure if they will make my car look better or not. I have a white 2000 gt and have dropped it 1.25 inch front and back. I still have about 1.5 inch wheel gap between my fender and tire. I'm now running 245x45x17s. I have now narrowed my wheel choice down to either the 1995 cobra R deep dish or the all chrome deep dish bullit wheels from american muscle. I am thinking the bullits are what I want, but am torn betwen the 17s and 18s... Which do you think look better setting the performance factor asside? I am leaning toward the staggared 165s front and 285s rear..

In reference to your discussion however, it would be interesting to do a test to see (2) identical cars ... One with 17s and one with 18s race. How much real time difference would you lose while running the 18 inch wheels. For those that don't race for high stakes, it probably wouldn't make much of a noticeable difference..

 

The 17 inch wheel may be lighter but the 18 inch wheel will give you a larger contact patch, so the difference will be negligible over all. Here's some 18 x9 and 18x10.5 Saleen knock offs on a lowered GT, with 275s and 315s