problem with my 18's
 

I just got some 18 inch rims for my mazda 6i already i can hear the back tires rubbing i was just wondering i anyone had the same problem or if its jsut my 6 if anybody has any suggestions let me no

RE: problem with my 18's
 

well all I can say is you better add some horses to your car, because your acceleration will suffer with 18'

RE: problem with my 18's
 

chances are you are gonna have to roll your fenders. i know that every person that has increased the size of the wheel has had to do so. what i would do is get a wider tire and lower the car. the bigger the wheel, the heavier it is as well (in most cases) so you lose a little power!

RE: problem with my 18's
 

What's the offset on the wheels?

RE: problem with my 18's
 

why do u guyz insist on beliving wheel size makes u lose power? not tru at all..........unless u go over ur stock radius of tire..........meaning the stock 6 comes with 17's already. with i belive 45 or 50 thickness tires........if u step up one size all u do is make the tire thinner...making the outer radius still pretty much the same. and even then if u go over the stock radius...u dont lose power.......u lose slightly on acceleration due to the larger rotating mass. hard to explain but u dont lose power. now if u went 20's u would definatley lose on accel, but still would only be a little

RE: problem with my 18's
 

The larger diameter the wheel the heavier it is. (For the most part...some ultra expensive large dia wheels are also fairly light.)

1 lb of rotating mass is the equivalent of 7-10 lbs of dead mass on a vehicle.

Braking distances/wear are also increased with larger diameter wheels due to the increased weight.

You're right, you don't lose power, you just accelerate slower.

Now if the 18" wheels you are looking at are the same weight as the 17" wheels that came stock, then there would be no performance decrease.

RE: problem with my 18's
 

...usually.

the fact that you are pushing the weight out a bit is the same as adding weight pretty much. i think tq is the thing that you notice, not power...it's the initial get-up and go that suffers typically. for those that daily drive the car, i really wouldn't worry about it...it's not that bad.

but you will need to roll the fenders for sure

RE: problem with my 18's
 

how did you paint your calipers and what kind of paint did you use

RE: problem with my 18's
 

tire circumference changes the gear ratio of your car thus affecting acceleration and top speed!

RE: problem with my 18's
 

a little is still a little. I wouldn't sacrifice 1 horsepower for looks!

RE: problem with my 18's
 

If you properly plus size the wheel/tire combination, there is no change in diameter or circumference.

i.e. a 225/40R18 is the same overall diameter/circumference at a 225/45R17.....There is a 0.48% difference between the 2 sizes.

You can use this tire calculator to figure out what size tire you need to maintain your current wheel/tire size

http://www.discounttire.com/dtcs/infoTireMath.dos

RE: problem with my 18's
 

Mazda guy, if that was the case, all out performsnce, you'd be running around on 16's, or even some 15's with the right offset. but that just looks dumb, so most don't go that route outside of the track.

i feel that if you want to roll on 20's more power to you, if you wanna run 15's that's all great. just find a wheel you like and go with it. but either way it will effect your ride and performance. I have a fairly heavy street set (2 sets actually) at about 21-23lbs each (just wheels) and a track set at 15lbs each...that's how i like it.

RE: problem with my 18's
 

you (might) add weight with a bigger mag .... but with a lower profile tire isn't it less heavy ?

also , slower to start (torque) , but will be easier on HP once you get rolling ... just think of those big wheels on a bike compared to small ones as you're pedaling

as mentioned , it's the radius/diameter that counts in the end

RE: problem with my 18's
 

Aluminum weighs more than rubber. Unless you go magnesium or to one of the lightweight wheels that are available, you most likely increase the weight of your wheel/tire combo by plus sizing.

RE: problem with my 18's
 

nah i think 17's are perfect.

RE: problem with my 18's
 

I put 17's on my 6 and i can hear it scraping on the back tires too. Mostly when i have people in the back seat. So i can imagine it doin the same with the 18's that you put on. Everyones talking about rolling the fenders, can someone tell me where you would have that done???

RE: problem with my 18's
 

not sure exactly how they do .... but I have seen a baseball bat being used .... could that be .... wedged in between the tire/fender ??? memory's unclear on that :(

RE: problem with my 18's
 

Check with a local body shop (not a dealership) about having the fenders rolled.

6 Pack, I believe you're right about the baseball bat. (I've heard of it being done that way.) Basically you are pulling the fenders out a little on each side creating a slight flare and rolling the lips from the sheetmetal away from the tires.

Again, if you're not sure how to do it, check with a body shop.

18's can fit fine if you have them set up just right (correct width/backspacing). I think the 18's are the best looking size, but 17's may be the best performing all-around.

I run the RX8 wheels on my wife's Mazda6 wagon (18x8 w/225/45r18 tires) and I'm sure that under the right circumstances (heavy load, etc.) that they would rub. Although we never heard them rub while they were on over last summer for ~12,000 miles worth of driving.

RE: problem with my 18's
 

hmm... i have never had any problems in my mazda6 with tire scraping. I've had a crew of 5 people in my car driving kinda like an ass to show of my car a bit and taking turns that were fairly sharp without powersliding and have yet to scrape. only problem i have had is the damn potholes. Had my one wheel dinged up and I know alot of people don't notice that, but I know it is there so that bothers me. The baseball bat method has definitely been used. My buddy did that trick to his truck to slap on bigger tires (he doesn't like spending money on fancy equipment that he will rarely use).

RE: problem with my 18's
 

The 18's won't rub , I suppose ... like sstlaure mentions ; 'cause they are 18 x 8 ..... usually a true 18 inch 'aftermarket' wheel will be at least 9in. wide for 18's ..... offset and backspacing and width play a decising role in the equation .

RE: problem with my 18's
 

it just happened that the subject was touched on slightly on my Mustang Forum and someone put up this link for rolling inner fenders , I haven't read it yet

http://www.bmwdiy.info/fender-rolling/