Any tire experts?

[1930]

I dont need a taller tire, Id like a wider tire, 2 inches wider would work and no less but could be 3 inches wider if thats all thats avail, how do I search, would these numbers somehow cross over into something I can use?

I understand that the numbers say a 15 inch tire, 275 I guess is the sidewall height and its a 60 series tire but how do I know the actual foot imprint and then get what Im after?

 

[1930]

These are the junk tires that are on the front, I dont like the skinny tire up front look so much, Id like a wider tire in the front as well within reason, ive got manual steering and thats not gonna change so what can someone reccomend?

I plan to get the BF Goodrich raised solid white letter tires assuming they are still avail and in the sizes Im after.

 

[AJ.]

275 is the width of the tyre in millimeters. The 60 is the wall height, 60% of the width.

Most tyre manufacturers have all the specs for their tyres listed on their website, I know BFG do as that is what I run.

Cheers Andrew

 

[tonyciambrone]

Yeah, 2 inches wider would be 325mm tires. I think with that much additional width you would be looking at getting wider rims. IMO

 

[L5wolvesf]

When I need to find or compare dimensions I go here - https://tiresize.com/comparison/

 

[38Chevy454]

As stated, 275 is the width in mm (~10.8 inches) and is the width at the bulge, not the tread width. 60 series means sidewall height is 60% of the width (.60 x 275 = 165 mm = ~6.5 inches). To be min 2 inches wider you need to add 50 mm to the width, or 325 minimum as suggested above. 25.4 mm = 1 inch for the conversion.

Use the same logic for the front tires.

 

[dbm52]

the first tire pic you posted is a 275/60 r15 that is a large tire probably pickup or suv. the second pic is a p205/70 r15. the r is just radial. the 205 could be a car or small pick up. what is this going to be installed on. a large front tire on a vehicle without power steering will be difficult to turn, also if it's a older vehicle with worn steering components will need a steering stabilizer

 

[moparguy01]

275-60-15 is a common muscle car size. In order to keep a tire the same height but wider like you want, you are looking at a 325-50-15. Nitto makes a 555 in that size, and Mickey Thompson makes some as well I think. These would be 2" wider. The problem is, you'd be needing a 9-11.5" wide rim for that size tire. You could put it on a 8" rim, but I would strongly advise against it.

The website L5Wolves posted is the best one that I've found to see the difference.

 

[Abeo]

In addition to the site listed above, I use the Tirerack site to look up common sizes, and to compare diameters (in inches)

https://www.tirerack.com/tires/tire...TARWL2V3&vehicleSearch=false&fromCompare1=yes

Click on "specs" to see what other sizes they offer for the tire, the diameter, recommended wheel width, etc

 

[jayoldschool]

https://tiresize.com/comparison/

 

[theoldwizard1]

You probably do not care, but IMHO anything <60 aspect ratio will give a pretty harsh ride.

 

[Hot Rod Grampa]

Many of the new tires are running 30 and lower aspect ratio. 19" wheel same od as old tire. Down side is no sidewall to absorb impact with pot holes or curb cuts. You damage wheel and tire. But handling is responsive since there is little sidewall deflection or tread distortion. Use the calculator mentioned above but remember the deflection in a corner can cause rub. Just thinking out loud.

 

[ard]

1. You cannot just increase the width of the tire WITHOUT increasing the rim width.

2. You cannot predict rid harshness only based on the sidewall PERCENTAGE. A 60 profile on a 165 will have the same sidewalls as a 315/30!!!! Approve

Op, three questions

What size do you have now
What rim size (dia and width)
What tire model are you seeking? If not specific, what type?

Generally you try to find the widest tire that will fit your width rim, keeping the overall diameter close.

 

[bushmechanic]

I dont need a taller tire, Id like a wider tire, 2 inches wider would work and no less but could be 3 inches wider if thats all thats avail, how do I search, would these numbers somehow cross over into something I can use?

I understand that the numbers say a 15 inch tire, 275 I guess is the sidewall height and its a 60 series tire but how do I know the actual foot imprint and then get what Im after?

Toss some math at it to find the actual footprint if that matters; or just get some chalk or similar up there, roll the vehicle, and break out a ruler on the mark it leaves.

Depending on what you're after, remember that taller tires are going to perform better under adverse off-pavement conditions when aired down, and wider tires perform better on pavement in general.

 

[Pluribus]

x3 on https://tiresize.com/comparison/

Another way to go at it is by using https://tiresize.com/calculator/ (different page on same site as above) to play with different possibilities. When you put in a size, it will give you options and prices. Once you click on a specific tire, the manufacturer will typically list recommended wheel widths to go with the tire. 38Chevy454 gave you a great example of the math (and what it means) you can use to plug in the right numbers for starters. The site will also show you some other tires that are similarly sized.

 

[ard]

You probably do not care, but IMHO anything <60 aspect ratio will give a pretty harsh ride.

I run a 315/30 tire on one car- so a 94.5mm sidewall

Compare that to a 165/60 tire.... 96.3mm sidewall

How can a 30 profile have the same sidewall as a 60 profile??

Are they the same 'harshness'?

You need to look at the sidewall height itself, not the ratio.

 

[bushmechanic]

I run a 315/30 tire on one car- so a 94.5mm sidewall

Compare that to a 165/60 tire.... 96.3mm sidewall

How can a 30 profile have the same sidewall as a 60 profile??

Are they the same 'harshness'?

You need to look at the sidewall height itself, not the ratio.

The ratio is required in order to accurately specify the sidewall height.

265/75R16:

1: 265 millimeter wide tread section.

2: The distance between the bead and tread section cap is 75% of 265 millimeters.

3: The diameter of the bead loop is roughly 16 inches when properly mounted.

That tells us that:

A: The tread section is 265 millimeters wide.

B: The "sidewall height" is 198.75 millimeters.

C: The tire will be 31.64 inches in diameter when properly mounted.

*Obviously, a lot of these numbers end up fudged to hell and back.

The ratio is key to the design of the tire itself, and describes the shape adequately. It's not unexpected that two drastically differently sized tires can share a sidewall height. Numbers fall where they will.

 

[LS6 Tommy]

I like this site:

https://www.wheel-size.com/calc/

It's really good for upsizing and checking fit.

Tommy

 

[bad_idea]

What are these wheels/tires on? How do you know you can fit a 2" wider tire on there? If using the same wheel (assuming it is wide enough), then one inch will go to the inside and one inch on the outside. I know that is basic, but I've overlooked it myself. Do you have that clearance?

275/60r15s are THE most common muscle car tire. Many manufacturers make them. May not be the case for the 325/50r15. On the front I would probably step it up to a 245/60r15 to fatten that tire up a bit (another common size).

Why do you want to step up the tire size? Aesthetics or performance? If for performance, then you can get a 275/60r15 that performs MUCH better than the BF Goodrichs.

 

[jloehlein]

Post up your wheel sizes, what car it's going on, and what you use the car for and people can offer more detailed help. For example, if you've got a 9" or wider rear wheel, you could run 325/50/15 Nitto drag radials. Obviously, you don't want to do that if you're daily driving the car, but you're the only one that knows that right now.

Are you opposed to buying larger diameter wheels? Wide tire selection is really limited in wheel sized under 18"

 

[JazzBlueRT]

You also have to consider what will fit in the wheel wells. You find alternative tires sizes by vehicle here;

http://www.automobile-catalog.com

 

[1930]

Thanks for the replies,

Heres what I have, maybe someone would be kind enough to hold my hand, rub my chin and tell me what I can get away with so I dont have to fry any more brain cells

1967 Ford Falcon: Not a daily driver, more of a weekend carshow deal and occasional run around ride.

Not sure how wide the rims on the rear are now but Im guessing with the pretty significant sidewall bulge I have now that they are pretty narrow so I was considering these rims http://www.ebay.com/itm/CRAGAR-610P...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649 or something similar.

I only ( now that I looked at it again today harder ) have about an inch between the spring and the tire that is on there now and I have almost 3 inches on the front until the tire would stick out past the body ( which I do not want )

I thought there was such a thing as an offset wheel where the hub of the wheel would be moved further back on the rim so as too even things out once the tire were mounted in relation to clearance front to back or distance from spring to outer qtr lip ?

When I put the qtrs on I rolled the edge to make room for more tire so there isnt an issue with the tire bouncing on the qtr since there isnt anything there hardly anymore.

I hope these pictures help

 

[ChevyEFI]

Do what everyone else fails to do:
Look up a chart of a manufacturer's tires with specifications.
One very important one is the mfgr. recommended wheels widths for each and every size.
A 255/60R15, for example, might be recommended to be mounted on 7.5" through 9.5" wide wheels (I guessed for the example.)

Generally speaking, your existing wheels look like they're about as narrow as you'd want to go for that tire size. A wider tire with the same (or lower) profile percentage is going to make the tread convex and wear out the center of the tire wear quicker, and it can be that way, even when they are run at a lower pressure.

Also, my example tire will have a slightly wider section width on a 9.5" wide wheel than on a 7.5" wheel. The ideal width for the hypothetical tire would probably be about a 9" wide wheel.

You're asking about offset. Negative offset is harder and harder to find. You (and me, until I make some changes) are stuck in the 70s which isn't bad. But, there are a whole heckuva lot more tire and wheel options if you put your car in the position to run positive offset wheels. I am ranting. Like that orange!

 

[ard]

I'd asked for the wheel widths before.

I will now add to that request "we need to know the offsets of the current wheels"

if you ACUTALLY want help, and not just comments and discussios, at some point you will need numbers. If you are planning on buyign new wheels TOO, then skip the width of the old rim.

BUT, to be able to place the new tire at the correct location in the wheel well, say 1/2" closer to the spring and 1.5" closer to the fender lip, then we need the offset you have now.

We are TRYING to hold your hand....meet us halfway, give us an offset



(PS all wheels have some 'offset'. google 'wheel offset'. It will tell you how to measure it too.)

 

[metlmunchr]

Aftermarket wheels in 15" diameter are generally going to be available in either 8" or 8.5" width, and from there they jump to 10" wide. For a 325 section width, you'd definitely need to go with a 10" width.

While wheels were specified by offset for years, the more common figure now for aftermarket wheels is backspacing. Offset is a measurement from the centerline of the rim to the mounting face. Backspacing is the measurement from the back side of the wheel to the mounting face. Your pic from the rear shows that you can't stand to have a wheel with more backspace than you have now, else the tire would be into the spring.

My guess is that your current wheels are 7" wide as that's the most common width for 15" Cragars. So, if you went to a 10" wheel, all the additional width would be on the front side (outside) of the wheel. At that point, there's no question that your 325 tire would be hanging outside the wheel opening. Glad to hear you don't want that, as it's one of those things that just screams that the car belongs to some goon who thinks a cartoon car looks good.

Don't be tempted to put a 325 tire on an 8" wide wheel. As mentioned above, it will compromise the tread life somewhat, but the stiffness of the structure under the tread makes this less of a problem with radials than it was with bias ply tires. The real problem with mounting tires on too narrow rims is that it decreases the lateral (side to side) stiffness of the tire. IOW, it makes the wheel want to wallow around with respect to the tread in turns, and has a major detrimental effect on handling.

If you were to go with an 8" wheel with 1/2" less backspace or an 8.5" wheel with the same backspace as now, and maintain the same 275 tire width you have now, it would fill the wheel well much more than the current setup without getting into the problems of hanging the tires outside the body. Either combination would move the outside face of the wheel 1.5" further out. In practical terms, a 275 section width is about the widest tire you can keep within the fender on any 60's era car without major body modifications.

 

[Pluribus]

You might want to look for a Ford forum with a Falcon section. I'm sure there are some people out there on the interwebs who can tell you exactly what tire sizes will fill the wheel wells and what backspacing you need on the wheels.

If you're set on a 325mm section width, my guess is you're going to have to mini-tub it and possibly even have to move spring perches. Based on above, my guess is you're just looking to fill out the wheel well without having to do big modifications. Forums are your friend.

 

[1930]

Thanks for the comments, I dont know how to measure offset, ( nor do I know the wheel width now since the tire is mounted and I cant afford to remove the tire and have it dead in my shop right now ) I didnt know this was gonna be such a big deal but to do anything right I know it has to be expected that one has to be an expert in that specific trade ( which I was trying to get away from )

Im not set on any wheel tire size, just want to make the most of having to buy new tires with a wider tire if possible than I have right now.

Ill keep poking around and figure things out starting with measuring my current offset and then seeing what the new rims might give me in comparison.

 

[1930]

Take a straight edge and lay it diagonally across the inboard flange of the wheel. Take a tape measure and measure the distance from where the straight edge contacts the inboard flange to the hub mounting pad of the wheel. This measurement is backspace. The photo below shows three wheels with 2",3", & 4" backspace.

 

[1930]

According to this guy

it does not matter if tire is mounted and I will get the measurements this A.M

 

[1930]

10 3/4 = 273.05
5 1/2 = 139.7

 

[1930]

My original plan was to get these rims blasted and powder coated black, If I cant get a significantly wider tire under there than Ill assume I can maybe push things a little further and put a little bit of a wider tire under there with these rims and save the cash ( or rather bill me later ) for something else.

One thing is for sure, I cant go any taller cause there isnt any more room and be comftorable

 

[38Chevy454]

10 3/4 = 273.05
5 1/2 = 139.7

Wrong way to measure. You need the distance from the wheel edge, not the tire bulge.

Also if you look on inside surface the wheel, you may find the size cast or stamped in.

 

[1930]

Wrong way to measure. You need the distance from the wheel edge, not the tire bulge.

Also if you look on inside surface the wheel, you may find the size cast or stamped in.

So you mean this guy

on You-tube is wrong? I dont believe it

 

[K13]

So you mean this guy

on You-tube is wrong? I dont believe it

He is measuring offset not backspacing just like it says in the title of his video.

Re read this from metlmunchr:

While wheels were specified by offset for years, the more common figure now for aftermarket wheels is backspacing. Offset is a measurement from the centerline of the rim to the mounting face. Backspacing is the measurement from the back side of the wheel to the mounting face.

 

[1930]

ok I see

 

[1930]

Sorry for the confusion, backspacing is 4 inches assuming Im doing it right and I measured the rim to be 8 inches wide

I see a bunch of info on back of rim but nothing that says this is my backspacing, hey you dummy, look over here