are my tires too wide for my rims

[lukedukem]

i currently have 275/60 r15 on the back of my charger. i read somewhere on here that those are too wide for a 15X7 wheel. something about turning corners and such. anyone heard of this. are they too wide. maybe 255/65? my fronts are 225/70 and one of them has a bubble in it so i need some new front ones, and i thought about swapping the rears at the same time. here is the only pic i have right now. the sun makes it look like the back of my car is missing.

luke

[Troy]

If you cut the back 3' off your car you don't need as much tire...

Tire companies will have recommended wheel widths for their tires and may be different from each other. BF Goodrich lists 7.5-9.5" for their Radial T/A in 275/60R15. They'll also list the "section width" (sidewall to sidewall) - in this case 11" on an 8" rim. If you try to "squeeze" a tire onto a skinny rim it will bulge - making it taller and keeping some of the tread from contacting the road. I'd imagine this will also affect the sidewall stiffness. If your rim is too wide the tire may not seat correctly (ie it won't hold air).

Troy

[lukedukem]

If you cut the back 3' off your car you don't need as much tire...

Tire companies will have recommended wheel widths for their tires and may be different from each other. BF Goodrich lists 7.5-9.5" for their Radial T/A in 275/60R15. They'll also list the "section width" (sidewall to sidewall) - in this case 11" on an 8" rim. If you try to "squeeze" a tire onto a skinny rim it will bulge - making it taller and keeping some of the tread from contacting the road. I'd imagine this will also affect the sidewall stiffness. If your rim is too wide the tire may not seat correctly (ie it won't hold air).

Troy

thanks troy, so if i read this right since my rims are 7" wide. then it is .5" too narrow. if a 275/60r15 needs a 7.5"-9.5" wide rim then i need to come down some.  my tires do bulge bad on the side wall, i can take a pic tonight and post it. as long as i keep the same height i can get a little skinny on the width. i think 255/65 will work. they are 10" wide compared to 10.8" that the 275 tires are. where did you find that info on the tires troy

Luke

[cbrestorations]

7" is too narrow, you get a big crown in the sidewall which is horrible for handling as the tread of the tire can walk side to side because the sidewall has no side load to hold it in place. if you try a slalom with what you have now and then the same tires on a 9-10" rim you will feel a big difference in how the car reacts to steering input and the ass end will feel much more stable. in circle track racing we were supposed to run 10" wheels but we tried 12" wheels on the same tire and dropped 4 tenths off our lap times, which is huge for only 15 sec. laps

[HPP]

Remember that is their recommendation. I've seen 295s on 7" rims and I've seen 275s on 10" rims. Obviously yours fit. However, as Troy points out, you tread contact may not be optimal at a less than recommended width, so you will have to drop pressure to create more tread contact. Lower pressure tends to provide less support for the sidewall and increase heat in the carcass.

How big of a difference will it make in regular driving, probably not much, if it is even noticeable. Can you tell the difference 1/2 tank of gas makes in under/oversteer? If not, you won't notice .5" of a rim difference and for that negligible change, you might as well pursue wider and larger diameter wheels and make the overall change more worthwhile.

[ACUDANUT]

I think 8 inch rims work best that tire size.

[lukedukem]

Thanks for the replys guys. I'm going to research sizes and maybe try to get a size I can rotate. It's just that I like the wider look, but if I get same size I can rotate. I'm headed to discount in the morning.
Btw cbrestorations, you where correct, the sidewall is way different than the 225s. But I don't plan on running track, but I get that the handling would still suck for street. Thanks

Luke

[lukedukem]

Not sure how big I can go up front now that I think about it. Maybe 245/60 is pushing it.

Luke

[cbrestorations]

keep the tires, get a bigger rim

[XH29N0G]

My guess is 245/60/15 on 15x7 is fine.  I run 245/60 15 front on 15x7s and 155/60 15 rear on 15x7. I don't think either ends up out of spec for the 15x7.  Maybe there is a handling difference, but I don't have my car set up for that. When I first started driving, I think I noticed a different feel with the tracking of the car, but not much. 

[lukedukem]

keep the tires, get a bigger rim

really cant afford 4 new tires and 2 new rims.

My guess is 245/60/15 on 15x7 is fine.  I run 245/60 15 front on 15x7s and 155/60 15 rear on 15x7. I don't think either ends up out of spec for the 15x7.  Maybe there is a handling difference, but I don't have my car set up for that. When I first started driving, I think I noticed a different feel with the tracking of the car, but not much. 

was that suppose to be a 7 or 9. you think 245/60 on these rims would work on the front. if so i just might put them all around

Luke

[HPP]

I'd run 'em until the tread is thin or they are too old to safely use, then downsize. I seriously doubt you'll notice the difference from a 275 to 255 on a street cruiser.

[lukedukem]

I'd run 'em until the tread is thin or they are too old to safely use, then downsize. I seriously doubt you'll notice the difference from a 275 to 255 on a street cruiser.

here are some pics of them. the only reason I'm talking tires is that one of my fronts has a bubble. and I'm not sure how old these are. they look pretty beat. they came with the rims. i thought about just replacing the fronts for now. i like where my RPMs are on the highway as well. that's the reason for keeping the 275/60. but if 255/60 look wide then i would be loosing an inch and gaining about 200RPM. which isn't much.

Luke

[XH29N0G]

keep the tires, get a bigger rim

really cant afford 4 new tires and 2 new rims.

My guess is 245/60/15 on 15x7 is fine.  I run 245/60 15 front on 15x7s and 255/60 15 rear on 15x7. I don't think either ends up out of spec for the 15x7.  Maybe there is a handling difference, but I don't have my car set up for that. When I first started driving, I think I noticed a different feel with the tracking of the car, but not much. 

was that suppose to be a 7 or 9. you think 245/60 on these rims would work on the front. if so i just might put them all around

Luke

Sorry - I use a 255/60 15 MT drag radial rear on a 15x7 (I wanted a little narrower than the 275/60/15 BFG which were on 15 x 8 and better straight line traction.  (BUT I do not drive in the rain)).  The section width is about 10.1-10.2 and contact patch about 9"  compared to 11" and 9.0-9.5" for 275's (I just measured mine and it looks like the contact patch is not that different, but the 255s don't bulge as much and are not as tall.    My guess is different brands make a difference in these measurements.

245/60 15 BFG radial front on 15 x 7 (I already had these).

The pic in the avatar is the 275/60/15 with 245 up front.  My impression is that the 255/60/15 do not fill the rear well nearly as much as the 275's but were wide enough for me.

I assume you have looked at the thread on wheel sizes.  There is also this one on 255s and I believe there may be some others too,
http://www.dodgecharger.com/forum/index.php/topic,98174.0.html

[lukedukem]

Thanks for the link. I'm confused about the backpacking stuff. I can't take my car up there to test fit them because of the bubble in the front.

Luke

[Troy]

If you cut the back 3' off your car you don't need as much tire...

Tire companies will have recommended wheel widths for their tires and may be different from each other. BF Goodrich lists 7.5-9.5" for their Radial T/A in 275/60R15. They'll also list the "section width" (sidewall to sidewall) - in this case 11" on an 8" rim. If you try to "squeeze" a tire onto a skinny rim it will bulge - making it taller and keeping some of the tread from contacting the road. I'd imagine this will also affect the sidewall stiffness. If your rim is too wide the tire may not seat correctly (ie it won't hold air).

Troy

thanks troy, so if i read this right since my rims are 7" wide. then it is .5" too narrow. if a 275/60r15 needs a 7.5"-9.5" wide rim then i need to come down some.  my tires do bulge bad on the side wall, i can take a pic tonight and post it. as long as i keep the same height i can get a little skinny on the width. i think 255/65 will work. they are 10" wide compared to 10.8" that the 275 tires are. where did you find that info on the tires troy

Luke

I got that information directly from BF Goodrich's web site. It's on the specifications for the tire. Most companies will have something similar. For overall tire heights/widths there are several good calculators on the web. I may even put one here as it's a pretty common problem that people have. I usually just type "tire size calculator" into Google. I use different ones because sometimes I need a comparison (side-to-side or overlay) and sometimes I'm looking at big mud tires.

I'd run what you have and plan for the future. I have 275, 255, and 235 sized rear tires on my cars. The Radial T/A isn't really a performance tire but I can definitely tell a difference between 235 and 255 in the rear. The only cars that notice the 275 difference are the ones with a big block. I can't vouch for the handling because most of my big block cars handle, well, they handle like they have a big block.

Troy

[cbrestorations]

 I can't vouch for the handling because most of my big block cars handle, well, they handle like they have a big block.

lol

[lukedukem]

thanks for the help guys. i haven't gone yet. i have to escort a backhoe to a customer this afternoon. so i might go tomorrow. it will give me time to think more on it.

Luke

[lukedukem]

I'm at discount. They legally won't mount the 275s to wide for rims. So the have 255/70. I gain an inch and less rpm on highway. But not sure how they look yet. Or 255/60, I lose an inch and gain rpms. Again only 200 rpm difference so I'm going with these 255/70 and if they don't look good I can get the others he said. I'll take pics side by side.

Luke

[ACUDANUT]

Did you already buy the bigger size. ? If so, you can always resell them. 

[lukedukem]

Did you already buy the bigger size. ? If so, you can always resell them.  

I haven't paid yet. Still here. He said I can take the 255/70 and if they don't look good bring them back for 255/60. They will refund me. These tires where from 1998. So they all have to go.

Luke

[XH29N0G]

If they are 1998, I would be careful and do a little looking into what issues could arise.  Saving a few $$ might not be worth it if there is a real potential for danger - especially if you are driving at speed.

[lukedukem]

ok, so i went with 255/70 which are 29" tall. the 275/60 where 28" but here are some pics. im only worried about how close they are to the fender in the back, i dont remember how close they were before. give me your honest opinion, if they dont look good, discount will take them back and let me get 255/60. which are shorter by an inch.

[lukedukem]

those where not as good pics

[XH29N0G]

I think the car sits nicely with them.

[ACUDANUT]

Heck I drive older tires than 1988. But they seldom see the sun, and that's what kills the tires.

[ikbrown]

Older than 1998 or 1988?? Cuz that's a big difference. Ha. I'm having to replace the tires on the front of my Charger for the first time since buying it back in 2005. Not sure the date on the tires but they were on it when we bought the car. Been garaged since then though so the tires look fine. My fronts got killed by a lack of an alignment and some serious negative camber on my driver side front. Whoops! Getting that fixed this month.

Luke, I think those tires look good!

[ACUDANUT]

yep. always check your alignment.

[lukedukem]

Thanks guys. Just wasn't sure about the height and being close to the fender. But they will work.

Luke

[nicjasno]

Anything older than 6 years is ancient in terms of tires. The rubber gets hard as plastic. I have a spare tire in my bmw that is 26 years old. Never used, but it's as if its made out of plastic. If i mounted 4 of those to the car, it would be an accident waiting to happen.

[375instroke]

Some tire manufacturers list 7" as the minimum for a 275/60-15.  Some list wider minimums.  If you want that mounted, just go to a different tire store.  Someone will do it for you.  I've run that size before in back, but the pressure was down to 18psi in order for it to sit flat.  I had a 235/60-15 on a 15X6.5 with 35psi in front.  Both tires looked too big for the rims.  I see your tires are wearing in the middle, a sign of overinflation.  That being said, ideally, that tire is too big for a 7" rim.  Here are some pics I just took of my car.  35psi front and rear.  The 245 may still be too big for a 7" rim.

275/60-15 on a 15X8




245/60-15 on a 15X7