Sticky #7: Tires for OEM 15 inch wheels

I put a set of Toyo Proxis S/T 295 50 15 on the rear and 245 50 15 on the ft check out my avatar for how it looks. I wound up googling ( is that a word?!) toyo tires with the size and then calling 4 pages of companys in order to find a set in Michigan.

I have not delt with the people below but a quick google found this.

Toyo Proxes S/t Tire P295/50r15
Toyo TiresToyo Tires Max Load = 2061;Tread Depth = 11;Overall Diameter = 26.5 for Jeep $132.99
http://jeepinguy.com/jeepinguy...hp?proddb=2&pid=3523

Now I think Dave and Linda Adler PI in Ca have some 305s if they have not sold them
quote:
Originally posted by Cowboy from Hell:
If it means anything to anyone ... LT stands for "light truck". Tires with LT at the end of the tire code are truck tires. This means they have more plies of steel & nylon in the sidewall, making the sidewalls stiffer, to prevent wheel damage when used off-road, and for carrying higher payloads. The rubber compounds are different as well, promoting longer tread life and less chance of damage (chunking) when used off road.

-G


Really? Cool! Baja! I'm in love.

Actually Cowboy, since I am in NY, the roads here are like a Baja for your life! Not just 500 miles! LOL!

There are no groundhogs to worry about, but the rats are the size of dogs. I hit one and at first thought it was a dog. I stopped and backed up. It was just a rat, and he was getting up. Must have just stunned him? Big Grin
Yes, 225-50 x 15s fit stock 7" Campys and 245-50-x 15 on 8" Campys both fit a stock Pantera front end. Tires in those sizes ARE available; what's not easily available are SPEED-RATED 15" tires. Finding V, Z or W-rated 15" tires isdifficult and when found they are not cheap. Larger width fronts reduces the understeer Ford built into the Pantera, as does changing anti-sway bar diameters and a host of other adjustments. Surprisingly, 8" Campys with 245-50s will steer easier than 225-50s on 7" Campys, due to the better scrub-radius of the 8" wheels.
PanteraDoug,

I got the aspect ratio using this size converter http://www.redrock4x4.com/tire...ButtonName=Calculate.

Glad you like the Sportsman S/R's. These are good for the rears but I think I'll need something different for the front (just as I had stated earlier). The Mickey Thompsons size 26X10.00R15LT ends up being metric size of 254/55/15.
That's too wide for me for fronts and the sidewall looks too tall. You can see this in the below photo. I think the rears look great but the sidewalls on the front look too tall:


Trying to match the S/R's tread pattern, I've found these:

http://www.wheelsnext.com/tire...O-Proxes%20R888.html

http://www.tirerack.com/tires/...lse&fromCompare1=yes

http://www.tirerack.com/tires/...GCID=C13674x012-tire

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quote:
Originally posted by pantera3322:
I was just told not having the same companys tires on the front and back will cause big handling problems . the larger BF Goodrich tires sounds good but the tires I have on the front now rub when you make a hard turn. Just would like to know if the 245 50 15 will they work .


That is an opinion. One with which I do not agree and I've been doing this a long time.

There is/are all sorts of BS permeated by the sales people at tire stores. They will tell you that you can't put two different size tires on a car also...and other Fairy Tales.

Do you know that when you tune a car for handling on a track most likely you will wind up with different tire pressures in all four tires? Let the experts explain that.



The BFG 245-50-15 will fit on the front with 8" Campis but you need to bend down the fender lips, possibly clearance the tire to the outer edges of the footboxes, and modify the windhield wiper motor cover. But yes if you accept that, it fits...I am told (Bosswrench).

I am also told that one car will require more work then another due to the production variations on the metal work from the factory.
Merging threads

quote:
Originally posted by Chris Wilson:
hey all I know there has been plenty of talk about 15 inch wheels and the lack of tyre avaliable to go on them. i press on regardless.

I have a set of 8's and 10's. here in nz i can locate 295 50 15s the best i can do is 225 50 15 for the front. the 225 seem a little stretched on the 8's.
the only 235 50 15 is a toyo 235 50 15 proxy R888
i was wondering about tyres with a 60 sized side all are there any thoughts re this, such as a 225 60 15
a
i can't find a 235 55 15 or a 235 45 15

Also what is the larges tyre that will safely fit under the front fenders of a stock pre l bodied car.

so comments please.

regards chris.

ps at this stage i am not prepared to go to the campy clones in bigger sizes.
225/50R15 is the correct size tire when the 15x8 Campys are used on the front. Its the factory size for that application. DeTomaso had the habit of using a tire on the widest wheel it was designed for. This makes the sidewall stiffer, reduces slip angles, sharpens response to driver input. The 225/50R18 has a fairly wide tread, about 8", so it fits an 8" wide wheel better than you may think.

The tire will fit and work fine on a 7" wide wheel too if that's your preference.

Regardless what tire you select, keep the front tire OD in the range of 24" to 25"

-G
quote:
Originally posted by Chris Wilson:
hey all I know there has been plenty of talk about 15 inch wheels and the lack of tyre avaliable to go on them. i press on regardless.

I have a set of 8's and 10's. here in nz i can locate 295 50 15s the best i can do is 225 50 15 for the front. the 225 seem a little stretched on the 8's.
the only 235 50 15 is a toyo 235 50 15 proxy R888
i was wondering about tyres with a 60 sized side all are there any thoughts re this, such as a 225 60 15
a
i can't find a 235 55 15 or a 235 45 15

Also what is the larges tyre that will safely fit under the front fenders of a stock pre l bodied car.

so comments please.

regards chris.

ps at this stage i am not prepared to go to the campy clones in bigger sizes.


The 225-50-15 works well on the 8" rim, or the 7". It is actually a small OD tire and lowers the front of the car about an inch. Be aware that if you have a US delivered car they had 1" spacers shimming the springs and if you take the spring spacers out, the lower radiator support is "way down there" vvvvvvvvvv(< arrows pointing down). My sons would say slammed but that is such ghetto term? Big Grin

Where as the car stock was about 43 inches high, it is now down there with the GT40 at around 40". The GT40 got it's name because it complied to the rule of being only 40 inches high. Wink

On my car, if I make a fist I have to turn it horizontal to fit under the nose. Verticle won't clear it.

The 295-50-15, probably a BFG, works ok on the back but the newer Mickey Thompsons, LT 26 x 12R15, although not high speed rated, fit really nice in the back on the 10" Campi. Fits the 8" too.

http://www.summitracing.com/parts/mtt-6654

It tends to give the car a slight rake, but you don't notice it while you are driving until you come up on a tractor/trailor when all of a sudden it seems like you can go right under the trailor? Eeker

This entire setup just lends itself to the feeling that the car is just some sort of a very highly powered Italian go cart? Works for me?

Ciao Bambino! Big Grin

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quote:
Originally posted by tajon:

Why is this George?


A front tire 25 inches in diameter fills the front fender arch quite fully, whereas a front tire smaller than 24 inches in diameter begins to look proportionally too small for the fender arch. Therefore front tire diameter should remain within the range of 23.9” to 25.0”. A rear tire 27 inches in diameter fills the rear fender arch quite fully, whereas a rear tire smaller than 26 inches in diameter begins to look proportionally too small for the rear fender arch. Therefore rear tire diameter should remain within the range of 25.9” to 27.0”. There is an aesthetic condition that must be considered when selecting tires. The front tires and rears tires should “fill” the front and rear fender arches equally. If a 25 inch diameter front tire is combined with a 26 inch diameter rear tire, there would be a situation where the front tire fills the front fender arch fully, while the rear tire would have a rather large clearance between it and the rear fender arch. There would be an aesthetic imbalance in the appearance of the car. As a result of this, the front and rear tires must go up or down in diameter together, or to put this another way the rear tires should be about 2 inches greater in diameter than the front tires (+/- 0.25 inch) in order for your Pantera to look its best. Therefore the diameter of the rear tire should be no less than 1.7” and no more than 2.3” larger than the front tire.

This also impacts the chassis ride height, i.e. the mechanical performance of the chassis. As the difference between front tire OD and rear tire OD decreases (less than 1.7") or increases (greater than 2.3") it "excessively" alters the chassis intended level ride height. This can be compensated for if the car has shocks with adjustable spring pre-load, but if the car has OEM shocks or red body Konis it can't.


Quickly, to set up a Pantera chassis with shocks having adjustable spring pre-load:

(1) set the rear ride height for level lower control arms (lowest setting, closest to OEM)

(2) set the front ride height to level the chassis. The chassis between the axles should be level with the ground, parallel to the ground, equal distance along its length to the ground. If you place a 2 foot bubble level on the door sills, they should be level. Leveling the chassis is important to give the chassis the "balance" that the designer intended it to have.

Changes to the front ride height will alter the bump-steer characteristics of the steering geometry, and the angles of the pivot axis of the upper and lower control arms. Changes to the rear ride height will alter the angles at which the half-shafts (and therefore u-joints) must operate at, plus the angles of the pivot axis of the upper and lower control arms. Combinations with greater front to rear difference in tire diameter make it necessary to raise the front of the car to level the chassis, this increases the gap between the front tire and front wheel arch. Combinations with less front to rear difference in tire diameter make it necessary to lower the front of the car to level the chassis; this reduces the gap between the front tire and the front wheel arch. Some guys do this intentionally in order to lower the CG of the car. Unfortunately this reduces ground clearance, and makes it hard to get a jack under the car.

The interaction of these parameters doesn't leave much room for customization, not like a good ol' American muscle car. But there's a lot of performance built into the Pantera chassis that those muscle cars will never have. If the front and rear tires are of the proper diameter, and their diameters are about 2" apart front to rear, and once the chassis is level, then control arm geometry, bump steer, front caster and appearance should all be "in the ball park". By appearance being in the ball park I mean the gap between the outside radius of the tires and the fender arch radius should be proportionally equal front tires to front fenders and back tires to back fenders. The tires should also be centered very well in the wheel arches. The factory set front caster should be at least 2-1/2 degrees, which is actually inadequate, it was originally intended to be 6 degrees, and should be at least 4 degrees. This causes the tires to lean into the turns, and gives the tires a better grip in corners. Ford intentionally dumbed-down the caster to 2-1/2 degrees in order to make the handling less responsive to driver input, i.e. that was how they "slowed" the cars handling. Ford also screwed-up the chassis set-up with the spacers they placed between the shocks and springs. and then there's the smaller rear anti-sway bar too.

The gearing, odometer, speedometer and rear wheel arch were all set-up for about 26.9" diameter rear tire. If the rear tires should be about 2" larger OD than the front tires, that means the front tires should be about 24.9" diameter.

Hope that gives you a feel for the interaction between all the components, and why we shouldn't stray to far from the originally intended settings.
I have an opinion, albeit one that few will agree with. I took my stock Campy wheels to the tire shop and had them fit whatever matched set of tires they had in stock (they have a performance-type tread pattern but were about $100 apiece, new).

You can go around and around discussing "correct" tire size, lack of availability of "correct" tires, speed ratings, etc.

I have yet to see or hear of any modern tire coming apart on any street-driven car, whether it's a sports car or Kia, b/c the speed rating was "too low." I routinely see folks driving on the freeway at 90+ mph for many miles, on off-the-shelf tires. Not once have I seen their tires disintegrate. How often do you really, truly, run your car at sustained speeds of over 100 mph on public roads? (don't answer that...) I'll bet there are not many folks here who have run over 100 for more than a few minutes anywhere for fear of the law. I haven't.

Perhaps if you spend most of your time at Talladega, then searching for the elusive super-speed-rated tires is worthwhile. However I chose not to spend $1,000+ on specialty Pantera wheels and $1,000+ on tires for a car that sees at best 1,000 miles per year. I oven-baked my stock wheels myself, had the tire shop put tires on, and spray-painted the wheels myself. The car has run at high freeway speeds and I've even drag-raced it. Everyone that sees it or rides in it comments on its superb handling and the good looks of the wheel/tire combo. The speedo reads pretty close. There is no mud nor rocks being thrown onto the body due to over-sized tires. Removing and installing the wheels is a breeze b/c they are light and small (relative to some aftermarket designs).

Again, I realize I am solidly in the minority here, and no one will agree w/ me, but my total investment is about $500 and the car still flies and gets many thumbs-up. My tires haven't exploded yet.

Just another option to ponder.
quote:
Originally posted by CB01:
I have an opinion, albeit one that few will agree with. I took my stock Campy wheels to the tire shop and had them fit whatever matched set of tires they had in stock (they have a performance-type tread pattern but were about $100 apiece, new).

You can go around and around discussing "correct" tire size, lack of availability of "correct" tires, speed ratings, etc.

I have yet to see or hear of any modern tire coming apart on any street-driven car, whether it's a sports car or Kia, b/c the speed rating was "too low." I routinely see folks driving on the freeway at 90+ mph for many miles, on off-the-shelf tires. Not once have I seen their tires disintegrate. How often do you really, truly, run your car at sustained speeds of over 100 mph on public roads? (don't answer that...) I'll bet there are not many folks here who have run over 100 for more than a few minutes anywhere for fear of the law. I haven't.

Perhaps if you spend most of your time at Talladega, then searching for the elusive super-speed-rated tires is worthwhile. However I chose not to spend $1,000+ on specialty Pantera wheels and $1,000+ on tires for a car that sees at best 1,000 miles per year. I oven-baked my stock wheels myself, had the tire shop put tires on, and spray-painted the wheels myself. The car has run at high freeway speeds and I've even drag-raced it. Everyone that sees it or rides in it comments on its superb handling and the good looks of the wheel/tire combo. The speedo reads pretty close. There is no mud nor rocks being thrown onto the body due to over-sized tires. Removing and installing the wheels is a breeze b/c they are light and small (relative to some aftermarket designs).

Again, I realize I am solidly in the minority here, and no one will agree w/ me, but my total investment is about $500 and the car still flies and gets many thumbs-up. My tires haven't exploded yet.

Just another option to ponder.


I saw a set of Firestones develope big bubbles in the sidewalls of the tires on a Shelby GT350.

Of course this was on a car that we counted made 37 runs on the dragstrip in one day by a guy we affectionately call "Mad Man" Aleberto.

I think they were F60-15's on 7" rims.

You are correct. They did not explode. MM kept driving with them to see if they would.

I personally have had chunks of tread come out of the tire on BFG's leaving nothing but the cord on two seperated occassions.

Neither of these tires were rated higher than S.

It all depends on where you look to find failed tires. The one place you don't want to hear of them is on your own car, but like all of us, "you pays your moneys, and ya' takes your chances".

As "Dirty Harry" once said..."do you feel lucky today...well do ya'?" Wink
Hi Chris...you helped me with the fan stuff..my turn to throw some info your way. I also have the 8 and 10 inch 15" campy's. They have the factory 225/50/15 on the front and 285/50/15's on the rear. The 225's are fine on the front. Lots of clearance. I wouldn't hesitate to use that size. I wish I had your problem. I have been trying to source 225/50/15's over here in Canada since last February without luck. hmmm...who's your supplier over there for the 225's..maybe I can get a quote for shipping. Again..go ahead with the 225/50/15 on the front...no problems...
Merging threads

quote:
Originally posted by johnek74Pantera:
Hi all. I have a new ( to me) 1974 "L" however it is fitted with 8" Campy's up front and 10"Campy's on the rear. I like the look of the rims and wish to keep them. I can't find a tire to replace the existing rears. They are 285/50/15's. Fronts are 225/50/15's and I have sourced a few of those, but nothing for the rears. Any suggestions aside from getting different rims? Does anyone know of a source for these tires or is there another size that will look the same and fit the rims? Thanks...

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