I’m rather excited to catch this truck, because it used to live here for many years, then disappeared for quite a few more years, only to return again. It’s a fine old classic F250, but what really makes it unique is its front-mounted spare, with air deflectors to help compensate for the air it blocks. But the best part is that spare tire itself: it’s a period piece, one I’ve been meaning to write up for years, but there’s none around anymore: a vintage Wide-Oval truck tire.
Firestone rocked the world with its Wide Oval tires in 1967, the first production tires with an aspect ratio of 70. Needless to say, they quickly became the hot new thing, and 70 series tires replaced the tall and skinny tires on performance cars almost instantly. And of course, they unleashed a progressive reduction in aspect ratio, with 60 series tires coming along just a few years later, and so on.
But what seems to be almost forgotten is that Firestone also tried to revolutionize truck tires with low-aspect ratio tires, at about the very same time. I’ve been desperately trying to find one for ages, and this is the only example I’ve come across, probably because it’s been sitting up there unused for decades. I still can’t find any information about the introduction of these truck tires, or its exact aspect ratio, which does look like it is .70 to my eye.
Actually, this one is a Goodyear, a “Hi-Miler Wide Tread.” As I remember it, Ford initially offered the wide Firestone tires as an option on 3/4 ton trucks, both the F250 and the E300 Econoline van, and I can confirm it was no later than 1968.
This one is a 9.50 – 16.5 LT size, but that was just the beginning. These tires soon spurred a fad, with even much bigger and wider ones soon becoming the the thing to have on the rear axle of one’s pickup in the seventies. 12.5 – 16 or 16.5 was the big bad boy, if I remember correctly, although I don’t think they had quite the low aspect ratio of these wide-oval tires.
The 8.00 – 16.5 Michelin radials on the truck now look positively dainty, especially on the extra wide rims.
Like so many old trucks like this, it gets pressed into seasonal duties; at this time of year, it’s to haul a load of fresh compost for the garden. With that spare tire in front, no doubt this Camper Special was originally bought to haul a slide-in camper, and the wide tires gave it extra floatation on stability.
Wow. Unless the size numbering system was different on truck tires, those things go back to the early 70s? By the mid 1970s they went to the numbers like G78-15 and not too long after to the metric numeration that I believe we are still using today.
I remember kids of the 60s oooh-ing and aaah-ing about performance cars with mag wheels and wide ovals.
Yes the numbering system on truck tires was different than that of car tires. Back in the day a truck tire had a nominal aspect ratio of around 100% to 105% while a car tire had a nominal aspect ratio of 82% to 90% depending on the era. The use of the numeric sizes continued on for heavier trucks for much longer than cars as most 3/4 ton and larger trucks used 16.5″ tires into the late 70’s and early 80’s while car tires switched to the alpha numeric sizes around 1970. For the alpha numeric sizes the letter corresponded to the weight capacity of the tire.
This gives a partial explanation, http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=45 while this chart give some suitable substitutes for car sizes. http://www.tirerack.com/tires/tiretech/45_conversionchart.html
When did the Goodyear Polyglas tires come out? They were also 70 series. My dad ad a set installed on his ’65 Plymouth Sport Fury in the summer of 1969 and they looked good!
Back in high school in the mid-’70s, when I bought my ’69 Mustang fastback for $800 (sigh), my best buddie’s dad was “the Mustang Man” in town. They had six boys, and when each of them got to be of driving age, they all got one of dad’s old Mustangs.
Mustang Man’s admonition about wheels and tires never left me: “You want 60s on the back, and 70s on the front.” When asked why he just kinda looked at me with that ‘You don’t know much, do ya boy?” look, and explained that the 60s would make it too hard to steer, and the 70s would be just right.
So when I finally saved up the bucks from sackin’ groceries that summer, I mail-ordered my “Turbine Mag” wheels and Dunlop GT Qualifier tires…and made sure I got 60s for the back, and 70s for the front.
Of course, then I had to install air shocks on the back to give it just the perfect “kick” to set off those wide tires…(and had to cleverly add some sheet metal under the back fender lip to keep ’em from cutting those 60s to pieces).
Oh, how I miss that car…
Look in late 60’s/early 70’s Popular Mechanics and Popular Science available on Google books for ads introducing the truck versions. Here is one http://books.google.com/books?id=ngAAAAAAMBAJ&printsec=frontcover&lr=&rview=1#v=onepage&q=transport%20wide%20oval&f=false
Note don’t confuse the Transport 500 Wide Oval truck tires with the “Wide base” or “Flotation” tires, like the one pictured, that also became popular around the same time. Flotation tires started off as only available for the new 16.5″ wheels with their unique bead profile and were of a nominal 75 series instead of the normal ~100 series truck tires commonly found at the time. The Transport 500 Wide Oval was available to fit the 15, 16, and 17″ wheels used on trucks at the time, in addition to the new 16.5″ “wide base/flotation” tires, I’m not sure what the aspect ratio of the ones for the even inch sized wheels were.
Meanwhile, my father is slightly peeved that the nearly-new 15-in standard tires from his daughter’s recently-departed Focus are too large to fit on a hay rack…
Another classic tyre (tire) is the Pirelli CN36. In the seventies and eighties that was all I would buy if I could find the right size. The super cool criss cross tread pattern was a great road holder. Sadly, these are not available in modern sizes but I believe limited sizes in 13 and 14 inch are being re made.
I believe these were standard fitment on original 911 Turbos before the P7 was developed.
KJ
My girlfriend at that time got a brand new 1973 VW Sports Bug (special edition Super Beetle) equipped with 175/70 Pirelli CN36 tires. The criss cross tread pattern sounds weird now but was hot stuff then.
Discussing tyres is completely out my comfort zone, but I recently found a whole book (!) on the subject by none other than LJK Setright. It’s now with David at Motor Book World in Melbourne if anyone wants. This is not a paid endorsement.
Wow I haven’t been there since before he moved the shop, and how long ago was that?
A long long time ago. I went to the old location a few years back and a hairdresser in the same strip looked at me as if I was deranged. He’s in Canterbury Road now, every time I go there I book out the afternoon because the conversation with David is great.
That is one awesome truck! Never seen one with a wind deflector, however. I remember radial ply tires didn’t become truly popular until after 1980. You couldn’t run them in an opposite rotation, separation was a common problem, road feel was compromised, etc. My ’71 Plymouth Fury I wagon owners manual specifically did not recommend radials, “the vehicle was designed for bias ply tires”, it read. I attempted to shod the ’68 AMC Rebel sedan with 70 series rather than the standard 78’s, but the tie rod ends rubbed on the wider front tires (on stock 5-1/2? wide rims), but the rear were okay. I always understood metric sizing perfectly , but never quite understood truck tire size numbers; 9.50 x 16.5? Of course the last number is always the rim diameter, that’s easy; but 9.50? Is that width? Where’s the aspect ratio? How about the size 31.50 x 15? Total height I suppose (rather than aspect), but what is the width? We used to call them twelve hundreds, eleven hundreds, thirty eights, forty fours, etc. Am I omitting or missing something?
For years there was the thought that a car needed to be “designed” for radial tires, but the reality is that the wheels are what need to be up to the task since you can put more side load on them with a radial tire. When I got my first SII it had radial tires by no hub caps. I got some aftermarket chrome wheels 15 x 7 and mounted 31 x 10.50-15 tires on it and eventually got some hub caps to cover the rusty wheels. I then decided to move those to my new Scout and decided to put some 235/75-15s on the stock wheels and put hub caps on them. I couldn’t keep the caps on the front wheels. After picking them up off the side of the road a couple of times I got another set of modern wheels and the caps stopped flying off when going around corners.
For the xx.5lt “wide base” tires the first number is the nominal width at the sidewall and the aspect ratio is a nominal 75%.
“Flotation” tires where the LT is after the numbers and the number does not include a decimal point like 10-15 LT or 12-16.5 LT the aspect ratio is a nominal 70%
Most of those are now gone and you’ll find tire sizes like 31×10.50-15 where the first number is the nominal tire diameter and the second number is the nominal side wall width. The aspect ratio can be calculated for those since, for example, you can also buy a 33×10.50-15.
Not exactly a truck tire, but a Wide Oval marketed to van owners.
Groovy!
I still think of “60 series” as low profile and I’m amazed when I glance over at a sidewall at a traffic light (how many out there are compulsive tire sidewall peeping toms? I love to read the names of off-brand and now Chinese tires) and see a /40 or /35 on a modern car.
Yup times have definitely changed there was a time not that long ago when a 60 series tire was the optional tire on a high performance car and now it is the base tire on a family sedan.
No mention of the trucks, but a nice summary of tire advancements in the ’67 FoMoCo line:
Dumb Question: did the change to the lower-profile tires (whether cars or trucks) need to be compensated for in terms of rear axle ratio?
Usually the shorter sidewall proportion was countered by a wider section, so OD of the tire remained the same. As profiles got lower and there wasn’t room for a wider tire, the wheel diameters increased to keep OD the same. 14″ to 15″, 15 to 16 etc. this was the so-called “+1” or “+2″ concept. Nowadays the 30 and 35 profile tires are often coupled with 19” or larger diameter wheels.
I was cleaning out the old garage where my model RR club used to be housed and in the back of the main building there was this spare tire sitting up against the wall. I’d never heard of the wide oval concept so this was a neat find after reading your article. Cool! (Dunlop, Gold Seal, Extra Heavy Duty, Wide Track are on the sidewall)
One more pic from today…
I have got a good one,