Wheel and tire sizes throughout history

[TJ Hopland]

Sitting in traffic recently I observed that it appears now that a compact car has 16" wheels.   18 and 20 are common stock sizes.  Got me wondering why.   Back in the wagon days I assume tall and narrow was due to road conditions and needing to be high enough to see over the horses.    Early cars had the problem of bad roads so tall and narrow was still the way to go.   

Roads got better / paved so we got smaller and wider?   Why?  Comfort?   Traction performance?   Cost?  Style?

Why the trend now to large rims and very little sidewall?  Seems like that is kinda how we started.   Why did we get away from that?    I don't know a lot about 20's and 30's cars but it almost appeared that the better cars had larger wheels.   A Packard had larger wheels than a Model T.  Why?   Seems like the better cars were the first to get the larger wheels this time around too.   Performance?   And the cheap cars are just trying to copy the nice cars?

[Jay Friedman]

I do know Ford Model As had 19" wheels.  In one year only, 1932, Fords had 18" wheels.  Then 17" for a few years and a 1941 Ford I once owned had 16" wheels.  As I remember, most US cars, including Cadillacs, in the late '40s and until the mid-50s had 15" wheels, then 14" wheels beginning in the late 50s. 

[Jon S]

I do know Ford Model As had 19" wheels.  In one year only, 1932, Fords had 18" wheels.  Then 17" for a few years and a 1941 Ford I once owned had 16" wheels.  As I remember, most US cars, including Cadillacs, in the late '40s and until the mid-50s had 15" wheels, then 14" wheels beginning in the late 50s.

Cadillac never went to 14" although other GM Divisions did.

[67_Eldo]

There are bunches of reasons for the changes in tire sizes, from the quality of available roads to the evolution of tire chemistry.

But, coincidentally, just yesterday I watched the "1938 Buick Y" segment of Jay Leno's garage. At about 8 minutes in, the subject of tires comes up.

https://youtu.be/LgMZDC-mK08?t=8m0s

[savemy67]

Hello TJ,

Interesting subject.  Part of me thinks that "what goes around, comes around".

At the very turn of the 20th Century, the bicycle craze was still extant.  Some of the first car builders - Mercedes, Duryea, even a young Henry Ford - adapted thin-spoked, narrow and high bicycle wheels to their prototype cars.

Within a short period of time, carriage makers like Studebaker and Buick - who were used to building, in some cases, heavier vehicles, adapted more stoutly-spoked wheels to what were becoming heavier automobiles.

High and narrow remained through the 1930's for many reasons: manufacturing capability, cost, styling, follow-the-leader.  World War II changed all of the above.

In a sense, the war placed mandates on the manufacturers.  Today, the government still places mandates on the manufacturers, especially in the form of the Corporate Average Fuel Economy (CAFE) regulations.  It seems to me that the trend toward larger wheels is one element in the manufacturers' process to increase CAFE.

Someone has calculated the marginal energy costs of rotating a wheel/tire with a larger circumference, and has concluded that the extra distance traveled by the wheel in one revolution provides a gain in MPG.  I expect to see more cars with larger diameter wheels in the future.  Note too that tire pressures have increased as well.  So what we will have in the future is a high, wide, bicycle tire.  As you mentioned in your post, "Seems like that is kinda how we started."  How true.

Respectfully submitted,
Christopher Winter

[TJ Hopland]

Is there a mechanical or efficiency advantage between larger diameter tires vs changing the gearing in the trans and or rear end to get to the desired engine RPM?

[Jay Friedman]

Cadillac never went to 14" although other GM Divisions did.

Jon, I stand corrected.  Jay

[wrench]

As streamlining became a design feature, the wheel/tire assembly had to fit into the enclosed fenders.

As horsepower improved, the 'contact patch' had to grow to accommodate traction and braking.

As suspensions imroved, the sidewall construction had to change to give a better ride.

As for low profile tires, except for some real performance cars, i think it is more form over function as popular tuner cars seek to give the illusion of performance (like having the eye on the back as if it is on the dyno so often that they don't need to take it off, etc) and urban vehicles tend to style more towards 'rollin' on 22s' or whatever the vernacular would be.

[cadillacmike68]

As streamlining became a design feature, the wheel/tire assembly had to fit into the enclosed fenders.

As horsepower improved, the 'contact patch' had to grow to accommodate traction and braking.

As suspensions imroved, the sidewall construction had to change to give a better ride.

As for low profile tires, except for some real performance cars, i think it is more form over function as popular tuner cars seek to give the illusion of performance (like having the eye on the back as if it is on the dyno so often that they don't need to take it off, etc) and urban vehicles tend to style more towards 'rollin' on 22s' or whatever the vernacular would be.

This is pretty much it. The "performance" illusion more than anything else has been driving this. And we get a harsher ride because of it. Not to mention no durability if a pothole looms up unexpectedly.

I actually saw chrome oversize wheels for the smart car (the one with three wheel lugs) in a wheel catalog the other day.

[The Tassie Devil(le)]

Wheels and tyres have always been one of the first parts of any moving object that can be changed at the whim of the owner to personalise their ride.

The same goes for the designers, and these people liaise with the engineers to bring Form to Function.

Looking back to the time when wheels and tyres were their smallest, the Mini, well, they had to be small so that they were a part of the suspension, and also had to fit the spare tyre within the confines of the then tiny body.

As has been said, the regulations that the designers have to meet have brought about the very low profile tyres to control sideways movement, and these would not have been possible without the road-makers making roads without wheel-destroying potholes.

The '50's and '60's was about soft-riding, and road handling didn't even get a look-in.   Hence the tyres went hand in hand with cushion riding suspension, but the performance cars still had different tyres.   The engineers found that the more sideways movement, the slower around a corner.

Just look at the Dragsters over the years.   Rear tyres are soft and squashy, but really grip, and grow in circumference, but try to go around a corner,......... well, lets not.

Still, in the top form of road racing, the Formula 1 cars still have "balloon" tyres, but their construction is also completely tied up with the suspension.

Our Cadillacs, although never going to small tyres, have had to use the tyres to carry heavy weights, and being "large" cars, they would look pretty silly with the 10" Mini wheels on them.   It is good that engineers and designers can be realistic at times.

Bruce.

PS.   Cadillacs did go to the ridiculous size of 13" with the Cimarron 

[64\/54Cadillacking]

It’s all about the looks. I remember growing up in the 90’s and early 2000’s when aftermarket big wheels with rubber band tires were “Cool” and really expensive at the time since many cars back then came with standard 15 and 16’s inch wheels. The aftermarket wheel industry was much larger in those days too compared to now. It was considered custom and a big deal if somebody had 18-22 inch wheels on there rides, now it’s normal and pretty much standard on all new vehicles.

 A bigger wheel with a short sidewalk handles a lot better than a larger tire and smaller wheel.

Is this all for the better? I don’t think so. Short sidewalls literally have ZERO flex and  simply can’t absorb as much road imperfections and potholes like a bigger tire can.

Every sedan I’ve driven, especially my 64 Cad, 94 Cad and old Lincoln’s with big fat tires, they all rode so much better than any new car I’ve driven.

Tires make a huge difference in how a car rides and drives, and unfortunately automakers have forced this change upon us due to the popularity of aftermarket big wheels.

Suspensions have changed because of the wheel size change, I suspect larger bushings are being used and more reinforced strut mounts and other components to help make the ride quality not as harsh and violent when going over potholes.

I still feel to this day that you cannot beat the isolated ride quality of 50’s-70’s Cadillac or a 70’s Lincoln that used a full frame, huge wheelbases and coil springs at all for corners.

As much as new cars have advanced, especially in suspension tech, its still very hard to beat the comfort of old full size Cadillacs from way back..

[The Tassie Devil(le)]

Oh, don't forget that one cannot fit big brakes in small wheels.

Bruce.

[tripwire]

What we are all forgetting about when it comes to tire & rim size is the influences current car buyers have been exposed to over their formative years.  It's got nothing to do with performance, ride, handling, technological advances; the real reason we see so many tall, wide tire/wheel combos is due to the Mattel Hot Wheels cars younger people grew up playing with.  If you give it some thought you'll recognize many styling/design cues these toys were/are responsible for.

My 2¢.

Wes in VT

[fishnjim]

Some points.   
Post wood, steel rim stock, the rolled steel that rims were made out of, was made in one US Steel location and provided all the stock for GM.   So that somewhat controlled the available geometry of the day.   The 14" v 15" was about the only change parameter except the hub.   The part the tire attaches to was the same and that only varied slightly.
As noted, the move to disc brakes required a larger diameter to get clamping forces.  Braking forces increase with speed and weight.   Drum has some limitations.   Anyone that has converted or tried to convert their drum brake car has encountered this constraint.
Newer technology for aluminum developed to allow these large alloy wheels.   As one increases the diameter, the centrifugal force increases and require stronger materials to resist these forces.   ie, You don't want your rim to fly apart at 70+ mph.
Design aesthetic is also in there.   eg;Alloy wheels don't require hub caps to achieve look, so eliminates manufacturing steps/costs.   

[TJ Hopland]

For the most part around 17" seems to be what you need for modernish brakes.   I'm sure there are exceptions but it seems like 90% of what you see the rotors look pretty tiny compared to the wheel size.