HiPerf_Chevyman

Just for the Rear, Will it Work?
Ive searched.. But I havent found a Solid answer.

, Nick Hall

online170

Yes, as long as its 15x7 it will work.

Some places selling tires have a fitment chart type of thing. I beleive the largest they will tell you that fits is a 265, but a 275 will work fine. Some ppl have even put 295s on. It will create a HUGE bulge outwards,and can affect performance of the tire somewhat. Also, the larger the aspect ratio, ie 50, 60, 70, the easier it is to put a wider than recommended tire on.

customblackbird

iTrader: (15)

yeah 275/50/15 is not gona fit on a 15x7 rim, sorry.

16x8 stock rims cant fit 275's on them the max recomended tire for a 16x8 is 255/50/r16 so a 275 has no chance on a 15x7 esp with 50mm sidewall height. the higher the side wall height will allow it to fit on a smaller rim but its not a smart idea. no ones gona put that 275 on a 15x7 for u.

online170

custom, first of all, have you ever fitted one on your 15x7 rim or tried to??? Im gonna guess not. 16x8 can take a 295 width, and so can a 15x8. But your right the aspect ratio should be ideally 60. I havent tried it with a 50, i missed that part, but if your goin with a stock rim and stock setup, it will accept a 60 aspect ratio fine.

Also custom, 275/50/15 does not mean it has a 50 mm sidewall. That would make it a 5 cm sidewall, which is barely 2 inches. A 275/50/15 has a side wall that is 50% of 275mm. A 275/60 has a sidewall that is 60% of the 275mm, and so on.

What you gotta make sure is you wheel is infact a 7in wide. The 6in wide ones will only accept up to 235 possily 245, depending on the aspect ratio.

You are going outside the recommended fitment by trying to squeeze a 275 on there, but it can be done. Let me find some pictures for you.
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custom, first of all, have you ever fitted one on your 15x7 rim or tried to??? Im gonna guess not. 16x8 can take a 295 width, and so can a 15x8. But your right the aspect ratio should be ideally 60. I havent tried it with a 50, i missed that part, but if your goin with a stock rim and stock setup, it will accept a 60 aspect ratio fine.

Also custom, 275/50/15 does not mean it has a 50 mm sidewall. That would make it a 5 cm sidewall, which is barely 2 inches. A 275/50/15 has a side wall that is 50% of 275mm. A 275/60 has a sidewall that is 60% of the 275mm, and so on.

What you gotta make sure is you wheel is infact a 7in wide. The 6in wide ones will only accept up to 235 possily 245, depending on the aspect ratio.

You are going outside the recommended fitment by trying to squeeze a 275 on there, but it can be done. Let me find some pictures for you.

Ok, the pictures quest didnt turn up what i was looking for, but u'll need an aspect ratio of 60. I beleive sonix's TA has had that tire on his car before.

customblackbird

iTrader: (15)

woah relax there jesus lol. ummm yea actually 275/50/15 is expained as 275mm as the width of the tire tread/ 50 is the mm height of the sideway of the tire/ and 15 should acrtually be written as R15 as in the radius of the rim size. sry but 50 is mm and its a 50mm side wall height . i have 245/50/r16 on my other trans am and 50mm is roughly 2" lol go look at tires, if u dont believe me feel free to go to a tire center and they will be happy to prove u wrong. as far as a 275 on a 15x7 rim is concered a 275/50/15 tire will not fit on a 15x7, hence u should go to a tire dealer and have them say the same thing. max tire size for a 16x8 rim is 255/50-45-40/r16 and most recomend 255/50/16 for a 16x8. as far as a 60mm sidewall instead of a 50 would allow fitment to a 15x7 rim....idk it certainly helps and a 70mm sidewall would be even better but now at 70mm sidewall height his tires are gona look HUGE and ugly, wat was the stock size tire of a 15x7 rim....hmm tell u it wasnt 275. and the fact that a 275/50/17 couldnt fit on my 17x8's....tells me u dont kno ur tires. ur prob counting the tread as part of the sidewall which it is not, once the side tread starts its no longer part of the sidewall. i just checked my 245/50/16's and they have roughly 2" sidewalls and my 17x8s have 245/45/17s and they have less hmmm guess i was right and i wasnt lashing out at u and all i said was a 275/50/15 will not fit and i am correct.

highper-chevy man u should to to a tire dealer and ask them wat will fit ur tire and rim combo and have them tell u what is allowed on that rim size. i kno that 275/50/15 will not fit on ur 15x7 rim bc i couldnt even get them on my stock 16x8's let alone my SLP 17x8's now. u will prob have to go to a 275/70/15 and u might have sealing issues but ur tires gona look like a huge slick with large sidwalls.

HiPerf_Chevyman

"I know that 275/50/15 will not fit on ur 15x7 rim bc i couldnt even get them on my stock 16x8's let alone my SLP 17x8's now."

Well, 275/50/15 If for a 15 inch rim. No wonder they wouldnt fit a 16 inch rim.. Let alone a 17..

I Have my own tire Changer. And I kinda like the BIG Tire look. Kinda Gives it a Muscle car Look, Not a sports car with 2" Sidewalls. Ugh, I'd Rather have 8 inch Sidewalls!

xpndbl3

iTrader: (5)

customblackbird, you are wrong. completely wrong. Does this 245/50 mean that the sidewall is 50mm tall? Then I guess the 35" tall mudders on my suburban that are 315/75R16 should really be 22" tall since 75mm is only around 3". Go to a tire size chart online and realize that the middle number is an aspect ratio which is a percentage of the first number. Secondly a 275 tire on a 7" rim will have the edges so cupped over that the total tire patch won't be the true 275 like if the tire was mounted on a 8"-10" rim. You might as well just run a 235/60 tire and call it a day on these rims.

customblackbird

iTrader: (15)

i realized that it fits bc the tire is 275/50/15, i was just trying to say that its a not stock size, nor is it recomened, or within optimal ranges. i just did a quic search on that size tire and the only thing that popped up was BF goodrich drag radials and hoosier R6 slicks... so yea theres no real tires that till fit the 15x7 rim with normal street tires. the search i use has almost all tires and it states that there are no street tires/performance/brands/speed ratings/runflat tires besides the drag radials. good luck trying to find street tires at 275/50/15 for ur rims...again just a quick search.
275/50/15 only 2 brands stated above
265/50/15 dunlop GT SUV tires
255/50/15 none avaiable
245/50/15 dunlop SP and Hoosier R6
235/50/15 none avaiable
225/50/15 has alot of brands bc that is the recomended tire not a 275, so i was correct about getting a tire to fit 275/50/15 on a 15x7 rim bc there are none avaible except drag radials which i didnt kno if thats wat u wanted.

no biggie if thats wat u want then get em if there avaible but those 8" sidewalls arent performance tires as in cornering which the 3rd gen is most noted for...again not knowing wat u wanted or wat type of tire u were looking for.

xpndbl3, ur tall mudders are SUV tires not a performance radial but are u also adding the tire tread to ur sidwalls? i am no tire expert i never claimed to be all i stated that a 275/50/15 tire on a 15x7 rim is not going to work and i stated that a smaller tread tire would be needed. the 245/50/16 on my 16x8 has a 2.5" sidewall height and there are 10mm in 1cm and 1cm is .39 of an inch which is roughly 50mm for 2" sidewalls. its just a quick way to figure the height of a tire without goin through the whole percentage deal. its not accurate but it gives u an idea of the sidewall height of a tire.

Sonix

iTrader: (1)

I'm running 275/60/R15's on my 15x8 wheels off a 2nd gen. Mwnova66 ran 15x7 wheels with 275/60/R15's tires. Stock wheels for his car. The 60 series is a tall tire, it jacks up the rear of the car a bit. I like that stance, but you need to be aware so you can tweak the outer fender, or else it'll slice your tire on bumps. (might just be the different backspacing on my 2nd gen wheels though)

I've thrown on a few pics of Matt's car, along with a small chart.
The chart shows 10.5" as being the biggest on a 7" wheel. 275mm/25.4mm per inch = 10.8"
They also say 12.5 is common on an 8" wheel - 12.5*25.4 = 317 ~ 315 tires. The tall sidewall makes it easier to stretch onto a skinnier wheel. You also get some nice protection for your wheels from curb rash. But even with steel belted radials, the sidewall will deflect if it's very tall, and cornering suffers. I think with proper tire inflation it won't "cup up" on the underside of the tire, such that you have less contact patch than with a skinnier tire, but I have no evidence to back that up. Checking the marks from a burnout would answer that one.

sp63

dude ive got to run yo over about the sidewall thing too.

its called aspect ratio. the second number is a percentage of the 1st number, and that last number "r15" or "r16, r17" whatever, does not mean radius. if it meant radius then that would make a 275/50/r15 tire fit on a wheel that is 30 inches tall. it stands for RADIAL. anyways, i think they pounded the aspect ratio into you good enough already so ill let that slide.

online170

Guys i was a little skeptical about the 275/50/15 fitting onto a stock third gen 15x7 rim, because i know the 60 aspect ratio has been done, but the 50 would make it a little tougher.

However, i was at a swap meet today, and a fellow had 15x7's for sale WITH 275/50...yes FIFTY.... R15 tires, inflated and installed on the rims. They were old tires, with probably the biggest "bulge" outward ive ever seen, and because of age and wear, they were cracking.

They were BFG Radial tires, their most popular brand, and fit just fine. So it can be done, i didnt have a camera with me unfortunately, but there ya go.

xpndbl3

iTrader: (5)

so the tires bulged out big time, but they fit just "fine". ok......

online170

yea thats right, they did fit just fine. They will wear evenly when inflated, and possibly a little bit more on the edges because its bulging.

The original question was, will it work??? Well i saw with my own eyes, sorry my budget doesnt cover a camera phone to show you guys, but when a tire is installed, inflated and balanced on a vehicle, not to mention used till the tread is nearly at the end of its life, i would say that it does fit just fine.

And can be used just fine.

The bulge is inevitable, when youre going over the recommended tire size, i would probably not go that wide myself, but hey it can be done.

BMmonteSS

No way it'll work "just fine" it'll be a compromised danger at best. The tire will wear right down the middle of the tire, think about it if you pull the sidewalls in that much you are going to bubble the tread. You'll probably even pull the eges of the tread off the ground, your 275's will only effectively be a 255 at best.

In a strait line, it may not kill you. In a turn these tires will handle horribly. With the sidewalls pulled in like they will be they'll have a nasty tendency to roll over in a turn. There is a very real risk of pulling the bead off the rim if you're not carefull.

You'll have just as much traction with a 245 or 255 tire on the 7" rim as you will use the full width of the tread. My wife runs a 245/50/15 on a 7" rim, they tend wear the center out of the tire with over an 1/8" of rubber on the edges. This is with 30 psi of air in the tires,we've experimented with running lower pressures but the handling suffers too much. I couldn't imagine running anything wider without it being drastically taller.

HiPerf_Chevyman

Okay, So if i can find 235,245,255/50's Will work? I dont want to Risk A blowout or whatever you want to call it.

xpndbl3

iTrader: (5)

i'd go with a 235/60R15 as that would be close to stock height for the tires.

HiPerf_Chevyman

Okay thanks! I get paid sometime this week. So I will get some tires and take pictures.. everybody like those..

Thanks again! Nick Hall

online170

yea ditto on the 235, because of the speedometer accuracy. However, 245s, are probably optimal for max tread width and keeping cornering performance. But with 255's your getting into the "bulge" zone again.

See if you can get a 245/55 or something to that effect to keep the stock height.

online170

Just wanted to revive this thread. A few heated arguments goin on in this thread.

First of all, i just wanna make it clear, that the question was, WILL IT WORK?
Not really. Will it fit though? YES it will...

My point:

-It'll fit, but dont do it, its dangerous.

Anyway, i didnt have a pic of the 275, but aparently you can squeeze some 295s on there too. Probably a 60 aspect ratio from the looks of it...... : crazy:

You know its bad, when you can SEE the "over inflation" sympton of a tire due to a large size,

There was a rear view too, but due to the plate, i dont wanna get anyone in trouble (ie: me).

Sonix

iTrader: (1)

oh, I thought you meant that was YOUR car, hot damn that looks good.
I'd like to see the tires from the back, if you could smear the license plate in mspaint?
I don't think the tires are going to fly off or anything, I imagine it's like removing the rear sway bar, kinda hurts handling but you're not going to spontaneously slide out of control in a school zone and kill 30 orphans while driving to church going 20 mph...

online170

Yea ur right nothing is gonna happen on the way to church, But still if you want those kind of meats, you prolly wanna go fast at some point. Highly unstable at turns, and awfully uneven wearing....

cooldbz12

What about if you just want them for the rear and say just for the 1/4 mile track, you think they would hold up and work?

online170

I dunno, i wouldnt try it with my car though. If you were gonna get them just for the rear, spend $50 on a used set of 8" wides and get 295s instead. Pairs of rims are much cheaper than a set.

yupitsdadsbird

WOW! ok I am a mechanic and I just read this and there is alot of crap and miss-idea's here.

they will fit the rims but not the car, they hit the inner-fender....u need a spacer 4 them too work......run ur pressure at about 26 and u'll leave a full foot print no problems.....I mean if u dive into a corner at like 80 u might get an issue.

the first # 275 is measured from the center of the sidewall (off rim), and the second # 50 is 50% of the first # (being from bead to total outside) and the last is obvious

and 275/50/15 is .2 inches or 2/10 of an inch shorter then stock 215/65/15

I have them on my car NOW, BUTTTTT I also have 10" rims on the car......when I get new tires 4 the back I WILL be putting 325/50/15 m/t indy profiles.

my cutlass btw had 275/60/15 on 6 1/2" wheels........when u have a tall buldge u do get alot of roll, but the 50's are shorter so they dont roll AS much

stingerssx

Yeah, so I'm gonna have to disagree. I have a set of turbo wheels from a second gen that are 15x8 and they have 295/50R15 on the rears and 225/60R15 on the front. I had them on both my '82 & '88 birds. No spacers, no fitment problems. And my '88 is lowered. When I got my '88, it had 275/50R16 on the stock 16x8 wheels in the rear. No spacers or fitment problems. None of them rubbed at all. Even when taking hard turns.

They did look really meaty though. So even though tire companies don't recomend them to be used, they can. Anyways, the tire companies are just covering their A$$e$.

Sonix

iTrader: (1)

You have 295/50's eh? I was thinking about that size, but they're so damn short that with steep gears it'd be like driving a tractor (just a bit more-so than it is now...)
But what's the backspacing on our 15x8 2nd gen wheels? Is it the same as 3rd gen 15x7s?

Stephen

iTrader: (12)

I've run the 275/50 BFGs (now discontinue by BFG) on my stock 16x8s...

I know a guy currently running the 295/50 BFGs on his stock 16x8s...

I'm either getting 295s for my 16s, or selling my set of gold crosslaces, and getting a set of ASAs.

sofakingdom

iTrader: (1)

Depends on what you call "work"....

If you like that hilarious and silly laughable Jared-before-he-discovered-Subway kind of bloated-out look, and don't mind your tire contact patch being a little stripe down the middle of a rounded tread, then yeah, it'll "work". For a few miles, anyway.

The biggest size that fits right, as opposed to merely "going on", is about 235/60. That's an excellent size for those little bitty pizza-cutter wheels.

225/60 is too small; it's a downgrade in load capacity (in most brands of them, maybe not all) from the already too-weenie stock 215/65.

Multiply your inches of wheel width by 25; that's its approximate width in mm. About that wide is the absolute lowest you can go and not pop the bead off the rim while driving down the street. Add about 40mm (1½"); that's about the ideal width. Or, add about 60mm (about 2½"); that's about the widest tire you can fit and expect to actually work like it's supposed to, and not curve the tread to where it becomes stupid, like driving around on balloons. Aspect ratio doesn't really matter, although the smaller it is, the less margin for variation you have. REAL SHORT sidewalls have to be on wheels that are REAL CLOSE to the right size.

By that rule, a 7" wheel is 175mm wide; add 60, that's 235. Amazing how well that works out.

Stephen

iTrader: (12)

.

yupitsdadsbird

yeah so let me guess then sofa ur the kinda guy that says the inflation stamp on the tire is how much HAS to be in the tire right? if u run the pressure up on a tire thats too wide 4 the rim it does ride on a stripe....and like I said u need to lower the pressure to make it work correctly. the 275's on my cutlass are set a 27psi and I run my camaro's 275's are at 25psi
when I spin my camaro all 7 tread blocks lay down. and my cutlass lays all but like an 1/8 inch on each side.
with tire sizeing u can go as big as u want on whatever rim u want.....

remember low rides back in the day........155/80/13 on a 10 INCH RIM? they rode on the damn sidewalls u lost 2 pounds in the things and they fell off the rim

and my secondary track tires I am getting are the 28x13.50/15s on 10's is that a danger too? and look stupid and gonna pop off?

the key is pressure not width

TBI89Formula

According to Mickey Thompson's FAQ link on their website, "The approved rim range for race tires is the tread width plus or minus 1". Using this rule of thumb and 275/50R15 tire with a tread width of 10" may fit ideally on a 9" - 11" wide rim. I believe this may be a good reference starting point however there are Outlaw 10.5 cars out there running the 33.0/10.5W-16 tire on a 16X16 rim.

sofakingdom

iTrader: (1)

No, I'm not THAT kind of guy.

I'm the kind of guy that you probably hated in high school (or maybe still do?). I'm the kind of guy that not only took courses like Physics, Latin, Chemistry, Calculus, and Biology; NOT ONLY made As in them; BUT ALSO, I stayed awake in them!!! And maybe worst of all, I still remember a little of what I learned. I'm the kind of guy that busted the "curves" for everybody in the sop classes that everbody had to take like History, and I laughed my butt off. Lots of people hated me.

I'm also the kind of guy, since I didn't sleep in Physics, who understands that the TIRE doesn't hold the car up, the AIR does. And that therefore, you need the correct amount of AIR to do the job. I'm the kind of guy that didn't do well in Art, though; so what something "looks" like is of no interest to me. It is not a concern to me when buying some part which I must constantly trust with my life, the life of my family, and the lives of all the other drivers around me. Like.... tires, for instance. I just buy the RIGHT ones, that FIT and WORK RIGHT, and I don't get all hung up on "looking" all high-school cool with big "meat" on my car. Especially not, if I have to let all the air out, just so that it at least pretends to work sort of right in one limited way.

Drag racing tires are a special case; the rules for what works in that specific application, and why, aren't the same as they are for street tires. Which is why anybody that tries to drag race on street tires has a MAJOR handicap to overcome. Drag tires are purpose-built, and different from street tires. They don't work any better on the street than street tires work on the strip. Not a valid comparison.

A proper size tire is one that fits square on the wheel, that is, the wheel is within the range the tire was designed to go on. Mismatching them, and then letting all the air out (or overfilling, would be just as bad) to make them "look" like they work, isn't the answer.

aletheian

iTrader: (1)

Just to revive a year old thread, and add my 2 cents. I've been running 245 50 15 on a stock rim for 3 years and than just this past year I've been running 275 50 15 on a 15x7 rim and I don't see any bulge, uneven wear or anything. I air them up about 5psi less than what they call for.

I am actually going with a 295 or a 305 on a 15x7 wheel. I've seen it at a ton of car shows, cruises, and online, without any problems. I drive my 85 TA about 500 miles a year, plus maybe one 150 mile trip to the beach and back, so I guess the danger thing isn't much of a problem for me.

squeeezer

to whomever is interested i can go to my garage and snap a couple of pics how p275/50/15 bf goodrich radial t/a's wear on 15x7 camaro wheels

they wear normal my right side wore more but both were even
this is a lot of work for me cause my computer keeps locking up
but i can do it to settle an argument
and technically the p275=sidewall to sidewall with proper inflation on proper sized wheel, not tread width
aspect ratio most of you got right the percentage of 275 mm

tony_cogliandro

iTrader: (3)

i was looking around at everything that was being written and i needed new tires so i went out and bought some 255/60 15 to put on my stock 90 rims. i wanted to see if they fit the front. if they didn't they would go on the back and 235/60 15 would hit the front. they do - just by a hair - so then i bought 2 more of the 275/60 15.
i like that old muscle car look - and that it what i have.
they look great from the back but i would be afraid to put 295's on those stock rims. at 275 you are already pushing the limits as they recommend a 7 1/2 rim and ours are only 7. but they do look good.
thanks for all the information i got on this board.

stroker_SS

[Just for future searchers]

A 295/50/15 is 26.76"
215/65/15 is 26.12"

Not short at all, as you can see there about the same height as stock.

White_Wolf

HI this will be my first post but i used to work in a tire shop and have some experience in this area.

First what you can do and what you should do are to different things. I recomend that you only put the max size approved on the rim. I run 235/60/15s on the rear and 215/60/15s on the front. i want to put 295/50/15s on the back but i like the stock rims, so if anybody know where to get a 15x8 that looks just like the stock rims please tell me. Well this is my $.02 on the subject. Oh and by the way how many peaple think white letters look good on a 3rd gen.

Stephen

iTrader: (12)

If you are that attached to the wheels you have, like I was to mine, you can send the rear 2 off to be custom widened.

I had 2 of my 17" ROH Snypers widened from 9" to 11".

I had mine done by Wheels America but there is also Weldcraft Wheels. Those are the only 2 that *I* know of, but sure there are plenty more, posibly one in your area.