15x8 Cragars

[hemi_jay]

Hey guys, I have 15x8 Cragar D-windows, 4" BS. I want to know what is the widest tire I can run. I plan on M/T ET street  275/60/15. will it work? I am going to be using a Ford 9" (cough) to what width must I narrow it? I don't have minitubs. I have seen some guys on the net say "No way you can only run 225 MAX!" and others saying 295 will fit. Any advice would be greatly appreciated. Oh and Im using MP .80" offset spring hangers and shackles. Thanks.  '68 Barracuda

[moparrr07]

roll the fender lip and some guys run 275

remeber there can be as much as a inch a difference between different tires with the same size rated

[guzzimike]

IMHO, 275s won't work on a streeter...

These are pics of my '68 Dart with CRAGAR/SS 15 X 9 fitted with BFG 255/60R-15 tires. Backspace is 5", tire Diameter is 27".

The only mods to the car are the Leaf Springs have been moved inboard .80" (with the spring-offset kit) and the inner fender lip has been rolled. As you can see, the tire rubs sometimes on the inner fender.

If you have a daily driver, I think that 255 is the limit for a non-tubbed wheelwell, otherwise you will be rubbing everytime that you turn a corner.

with 15 X 8 wheel with 4" BS, I would not go wider than a 245, if that... Anything wider and the sidewalls would bulge out and cut down your clearance even more.

Just my opinion, YMMV.

[moparrr07]

whats the actual size of that tire,

many other guys have run a 285 in that well

[guzzimike]

The tire is a BF Goodrich Radial T/A, 255/60R-15. It's 27" diameter, 10.2" wide at the thread, 11" at its widest ( bulged out sidewall) point.

The Wheelwell in my 1968 Dart GT is exactly 12" wide at its widest ( rolled up lip) point. I have about 1/2" clearance on either side.  You can see in the pic above where the tire rubbed the inside wheelwell as it is...There is also a bulge right above the inner, rolled up lip area where the outer part of the tire also rubs when the car is driven semi-agressively around corners or over railroad track and bumps (you can see the linear scrub marks on the outer part of the tire sidewall in the first pic). This car can carry 4 grown adults, but barely. You really have to watch your driving with 4 people in the car.

A 275 might fit with about 1/4" clearance on either side of the tire, but it would rub at every turn or dip in the road. And forget about carrying more than two grown people.

A 285 or 295 is someone's wishful thinking, unless their brand tire measures vastly differently than a BFG or if my Dart is an anomaly that came with narrower wheelwells. 

I did quite a bit of research on what tire brand would best fit my car and its intended purpose as a daily driver, and the BFG 255 T/A offered the widest tire that would work in real world situations.

[moparrr07]

ok, a 255 converted into standard measurements is 10 inches wide, where as yours is 11, it is an actual 280 in metric sizes, so a 275 of another brand might be smaller

[guzzimike]

ok, a 255 converted into standard measurements is 10 inches wide, where as yours is 11, it is an actual 280 in metric sizes, so a 275 of another brand might be smaller

Actually, my 255 is a bit over 10 inches wide, NOT 11 inches.

This 10" is at the widest THREAD width. And in reality, it's a little bit over 10"..

The tire is 11" at its widest point, IOW,  at the sidewalls with the car's weight on them...

But the point I'm trying to make is that for a daily driver, I would not go over a 255....

Trust me on this, I really would love to fit a 275, 285 or even a 295 if I could, but it would not work for my car.

[moparrr07]

exactly, the 255 in the measurement is a measurement of the section width (sidewall or widest part) 255 is the millimeter measurement 255 divided by 25.4 conversion =10 inches

so you have yourself a true 275 tire in there

the # on the tire is section width, not tread width

and by the way, i have found that the Yokohama avid s/t is best for a daily driver because it can get loads of traction in the rain and you can get it up to a 295, it offers way better handling characteristics than the t/a, not to mention 60k mile tread wear on average with proper rotation and its cheaper

[guzzimike]

EGADS..

OK, one Last time....What I have on my car is a 255/60R-15



Not a 275....DO YOU UNDERSTAND THIS PHOTOGRAPHIC EVIDENCE..

The 10.2 Inches is the threaded footprint width of my tire...in addition to that, the tire bulges out about 1/2" on either side for a True (as in: Real World) 11" total width. Since my wheelwell (with rolled up lip and springs moved inboard .80")   is 12" wide, this allows me about 1/2" clearance on either side of the tire..and this clearance is just barely adequate at times.

 A 275 will not work in there, much less a 295.

I have been running this BFG tire on this car for close to a year of normal daily driving, and I am completely statisfied with its performance in wet or dry, Street and Freeway, regular and "spirited" driving..

But, Hey, knock yourself out and go fit a set of 295 in your car..It's your money.

Remember...measure twice, order once..

[68_GSS]

Section width for BFG's:

245/60-15 = 9.8" on 7" rim

255/60-15 = 10.2" on 7.5" rim

275/60-15 = 11.0" on 8" rim

[guzzimike]

Section width for BFG's:

245/60-15 = 9.8" on 7" rim

255/60-15 = 10.2 on 7.5" rim

275/60-15 = 11.0 on 8" rim

Yes...then add another inch (total) for the sidewall bulging distortion. Remember that these are radials. The sidewalls bulge, especially with lateral inputs, such as turning corners..

This is why I could not Fit a 275 in my 12" wheelwell...

275 = 11.0 (+ 1") = 12"

[68_GSS]

These measurements are from mounted tires. The "radial bulge" would be on the bottom portion of the tire, that contacts the road.

[moparrr07]

i understand what your saying, listen to me-

what is writen on the tire is not the actual size

if you buy a 33 inch off roading tire, it actually about 31 inches tall

the section width is the width at the widest part of the tire

basically bfg says its a 255 but its not

a true actual 255 would be 10 inches at its farthest part, a truly marked 275 would be 11 inches wide at the widest part

yes your tire say 255 but its really a 280

TIRES ARE NOT ACTUAL TRUE TO SIZE OF WHAT IS PRINTED ON THEM

btw i am mini tubing with a 295 street and 325 strip tire

a true to size 275 is the most that will fit in the stock wheel well, i say a 275 in tire as in a tire that is 11 inches of section width, at the widest part not the tread

understand this phrase :TIRES ARE NOT ACTUAL TRUE TO SIZE OF WHAT IS PRINTED ON THEM

[guzzimike]

These measurements are from mounted tires. The "radial bulge" would be on the bottom portion of the tire, that contacts the road.

  The radials, by the natue of their construction, have more lateral "Give" than Bias Ply tires...They bulge at the bottom and flex (bulge) at the top, especially so when in a turn.

[moparrr07]

yup, thats why they look like they are low, compared to a biased ply

[68_GSS]

I just pulled a BFG 255/60-15 radial mounted on a 15x7 rim off of my Dart. Sure enough, the cross section is 10-1/8 inch, very close to what a BFG tire chart says.

On a side note, I measured the wheel well on my 68 from inside to the original non rolled fender lip. It is 12 inches at the widest part.

Can supply pictures if needed. 

[guzzimike]

i understand what your saying, listen to me-

what is writen on the tire is not the actual size

if you buy a 33 inch off roading tire, it actually about 31 inches tall

the section width is the width at the widest part of the tire

basically bfg says its a 255 but its not

a true actual 255 would be 10 inches at its farthest part, a truly marked 275 would be 11 inches wide at the widest part

yes your tire say 255 but its really a 280

TIRES ARE NOT ACTUAL TRUE TO SIZE OF WHAT IS PRINTED ON THEM

btw i am mini tubing with a 295 street and 325 strip tire

a true to size 275 is the most that will fit in the stock wheel well, i say a 275 in tire as in a tire that is 11 inches of section width, at the widest part not the tread

understand this phrase :TIRES ARE NOT ACTUAL TRUE TO SIZE OF WHAT IS PRINTED ON THEM

Ok, so what you are saying is that when you advice people to get a 275 (as "adverstised"), you are actually telling them to get an "actual" 295 or so, which, in either case.. they are fo0kked....because you didn't qualify your advice, until now..

You should really qualify your advice. Not all are as tire-savvy as you..

Most people shop for and buy the tire according to what it says on the sidewall, not according to "Theoretical" or "actual" values..

BTW, a "true to size" 275 may fit a stock wheelwell, but it won't work worth a dime as a driver...it's going to rub at every little dip of the road and at every corner. And you had better have an Anorexic for a girlFriend, too..

Also, you should write to the tire companies and tell them they have it all wrong and to stop with all that false advertisingon their sidewalls..

Imagine; Tire companies selling tires that are actually larger than advertised...What a concept..!

What's next: Buy 4 -  Get one free..?

[NYrr496]

   You guys are crackin' me up.

[68_GSS]

  You guys are crackin' me up.

  Ya, go measure a tire! 

[guzzimike]

  You guys are crackin' me up.

  Ya, go measure a tire! 

I DID..!

I went outside, unzipped my pants, took out my ruler...and I'll be damned if that tire wasn't 11"  FER SUR..!

[moparrr07]

no, im not saying every tire is off 20 mm im saying actual is not alway what is writen, i have poll off a tire and put on a different brand of the same size before and they were a 1/2 in wider

68 gss- is it the tread width or the section width? cross width is a inaccurate term

most tires are a tenth in ch or so, but there are some that are way off

if you think tires are what they have writen on them, then explain to me why you measured your tire to be 11 inches wide or 280 mm wide? when you claim it to be a 255

[68_GSS]

BFG 255/60-15 mounted on a 7 inch steel rim has a section width of 10-1/8 inch.

[moparrr07]

ok then, thats settled( i still stand by what i said before on how some tires arnt what they reflect), i guess guzzimike doesn't know how to use a tape measure, it was 10 and how many lines?

[guzzimike]

Moparr07, I have said all along that my 255 mounted on my Cragar /SS 15 X 9 rim has a thread width of 10.2 inches..which is the Decimal equivalent to about about 10-1/8th Inch..(in case that you didn't know your decimals or ran out of fingers to keep count) 

The OVERALL ( largest) sidewall to sidewall width is wider than the thread patch, it is actually 11"

Look at my 2 photos that I posted up earlier..My Wheelwell is 12" wide. I have about 1/2" (.50 Inch) Clearance on either side of the tire..

Can you see that..?

Good. Now let's do some simple math, shall we..?

12" - (1/2") - (1/2") = 11"

Do you agree..?

Good. Then that means that my BFG 255 mounted on a 15 X 9 wheel is ELEVEN INCHES WIDE AT ITS WIDEST POINT.



 

 
 

[68_GSS]

The OVERALL ( largest) sidewall to sidewall width is wider than the thread patch, it is actually 11"

Look at my 2 photos that I posted up earlier..My Wheelwell is 12" wide. I have about 1/2" (.50 Inch) Clearance on either side of the tire..
 

I can't figure that out guzzimike, the wheel well lips are folded over and the total measurement is 12 inches.

My 68 has stock wheel well lips, and that measures 12 inches. 

[guzzimike]

I can't figure that out guzzimike, the wheel well lips are folded over and the total measurement is 12 inches.

My 68 has stock wheel well lips, and that measures 12 inches. 

Yup, with lips rolled over and .80" shackle spring relocator kit I have exactly 12 Inches of width at the wheelwell...We even took a hydraulic jack and a piece of 2 x 4 and flattened the bump on the inner fender as much as we could, within reason..

Again, trust me when I tell you that I looked and tried to fit the biggest, (reasonably priced) Daily Driver tire that I could, and the BFG 255 was it.

At one point in the process, we actually fitted a BFG 275 on my Cragar rim and when we mocked it up, the clearance was about 1/4" - 5/16th" on either side....No way was that going to make it as a daily driver...We'd be gouging into the tires at every little bump and corner turn.

If you look at the pics I posted earlier, you can see where the 255 tire actually scrubbed a black patch against the inner wheelwell. On the other pic, you can see the radial scars left on the outside sidewall of the tire, where it scrubbed against the rolled up lip. And this is with Air Shocks in the rear to stiffen the body roll, and.......

[hemi_jay]

this what I want to run:  Mickey Thompson 275/60-15 ET Street Radial, tread width is 9.2" and section width is 11", moparrr07 you sound educated enough to answer if it will work. Guzzimike, thanks for the input, but my car won't be a daily driver- no-one will ever sit in the back seat and I have Superstock springs,

[moparrr07]

guzzimike, it seems the reason your measures so wide is because its on a 9 inch rim, look at gss's pictures of the 7 inch rim, if you would mount that tire on a 7 inch rim, it wound have more clearance and you could have put a 275 on a smaller rim and have more tread with less section width

hemi jay- they say that it is 11 inches wide on an 8 inch rim, so, it would be about the same size as mike's 255 on a 9 inch rim, so if you roll the lip, then it will fit, just make sure that you have the correct backspacing

lots of guys around here are running 275

here is a picture of abodyjoe's 275 under his dart and his is 11.8 inches wide

[daniel_depetro]

Abodyjoe also has low profile tires so he doesn't have to worry about tire sidewall flex or the sidewall adding width to the tire.

[moparrr07]

a 275 width in a 17 inch tire is the same as a 275 width in a 15 inch tire, you get more tread out of a 17, but the section width doesn't change