Why Tires Used to Be White (and What 100 Years Changed)
A hundred years ago, tires were white. Not whitewall — the whole tire, sidewall to tread, the colour of a bar of soap. And they lasted about as long as a pair of shoes. The tire under your car right now is black, lasts many times longer, and tells you it's low on air before you can feel it. Two things got us from there to here, and the first one was a war. Here's the whole story in under a minute, then the detail below.
The short version:
- Early tires were white because natural rubber is off-white and makers added zinc oxide to strengthen it
- World War One took the zinc, so factories switched to soot — carbon black — and rubber became roughly ten times more wear-resistant
- That didn't fix punctures: dirt roads were full of horseshoe nails, and every car shipped with a patch kit
- Michelin's 1946 radial roughly doubled tire life again and cut punctures
- Today a tire holds 200+ raw materials, silica for cold grip, and a pressure sensor in the wheel
Why tires were white in the first place
Untreated natural rubber is a milky, semi-translucent ivory. On its own it's soft and wears quickly, so the earliest tire makers mixed in zinc oxide as a strengthening filler. Zinc oxide happens to be brilliantly white — it's the same pigment in old house paint and sunscreen — so tires came out of the mould bright white. That was simply what a tire looked like in 1910. Nobody chose it for style.
The problem was that zinc-strengthened rubber still didn't last. Drivers of the era measured tire life in a few thousand miles, and on an early Ford the front tires ran at 55 to 65 psi and the rears at 60 to 70 — narrow, rock-hard, and easy to cut. A set of tires was a running expense, not a purchase you made every few years.
The war that took the zinc away
When the First World War started, zinc oxide became a munitions material and supplies for tire makers dried up. Factories reached for the cheapest filler they had on hand: carbon black, essentially refined soot. It had been known since around 1904 that carbon black stiffened rubber, and B.F. Goodrich famously bought its early supply from Binney & Smith — the company that makes Crayola crayons. Around 1917 the switch became general, and tires have been black ever since.
The change wasn't cosmetic. Carbon black bonds with the rubber's polymer chains and makes the compound far more resistant to abrasion and heat. Michelin's own material engineers put it at roughly a tenfold improvement in wear resistance, and it still makes up 25 to 30 percent of a tire's rubber by weight today. The often-quoted figure of the era is that a good white tire was finished at about 5,000 miles while a carbon-black tire on cord construction could run toward 50,000. Overnight, the tire went from a consumable to a component.
Why that still wasn't enough
A tire that can wear for tens of thousands of miles is only useful if it stays inflated, and in the 1910s and 20s it didn't. Roads were unpaved and shared with horses, and a shod horse sheds nails — eight to ten per hoof — so the ruts were seeded with iron. Ford shipped a tire repair kit with every Model T, and most drivers carried tire chains under the seat. On a long trip the question wasn't whether you'd get a flat, it was how many. A flat wasn't bad luck. It was Tuesday.
Better rubber solved wear. It didn't solve the structure of the tire, and that's where the second breakthrough came from.
1946: Michelin turns the cords sideways
Every tire is built on layers of cord — originally cotton, later rayon, nylon, polyester and steel. Early "cross-ply" or bias tires ran those cords diagonally, criss-crossing from bead to bead. It worked, but the plies rubbed against each other as the tire flexed, building heat and wearing the casing out from the inside.
On June 4, 1946, Michelin registered the patent for the radial tire: cords running straight across the tire at 90 degrees to the direction of travel, with a stiff belt under the tread. The sidewall could flex independently of the tread, so the tire ran cooler, kept a flatter contact patch on the road, and resisted punctures better. Michelin's figure was roughly twice the service life of a cross-ply tire, with better wet grip and lower rolling resistance as a bonus. The Lancia Aurelia was the first production car to get radials in 1951; the Citroën DS followed in 1955, and within thirty years virtually every passenger car on earth was on them.
What's actually in the tire on your car today
A modern passenger tire is built from over 200 raw materials. About 60 percent of the rubber is synthetic and 40 percent natural. Carbon black is still there for wear. Steel belts and textile plies carry the load. And since 1992, silica — fine sand, chemically bonded into the rubber — has done something carbon black can't: keep the compound flexible and grippy on a cold road while still rolling efficiently. That silica chemistry is the reason a proper winter tire stays soft at −30°C on a January morning in Calgary, and it's why we're blunt about all-seasons not being winter tires here.
The last piece is the sensor. Virtually every new car sold today carries tire-pressure monitoring, so the tire tells you it's low before your hands can feel it in the wheel — which is exactly the failure that stranded drivers a century ago. From a patch kit under the seat to a warning light on the dash, in one lifetime.
What this means for you
The tire under you right now is a hundred years of people who were sick of changing flats. The wear problem is solved, the puncture problem is mostly solved, and what's left is the part the engineers can't do for you: keeping it inflated, rotating it, and running the right compound for the season. If you're not sure your set is up to a Calgary winter, bring it in — we'll check tread depth and date codes for free, and we're happy to run the cost-per-kilometre math on a replacement. Book online or call (403) 452-4283. We're at 111 42 Ave SW and 3928 Edmonton Trail NE, Calgary.
Frequently Asked Questions
Why were old tires white?
Natural rubber is a milky off-white, and early tire makers added zinc oxide to strengthen it, which made tires bright white. Black tires only arrived when carbon black replaced zinc oxide as the strengthening filler around 1917.
Why are tires black today?
Because of carbon black, a fine soot-like powder that makes up roughly 25 to 30 percent of the rubber compound. It makes rubber dramatically more resistant to wear and heat, so every modern tire uses it.
How long did tires last 100 years ago?
Early white tires were often finished after a few thousand miles, and punctures were routine because unpaved roads were littered with horseshoe nails. Cars of the era shipped with a patch kit and pump as standard equipment.
What did the radial tire change?
Michelin patented the radial in 1946. Running the cords at 90 degrees to the direction of travel instead of criss-crossed gave roughly twice the service life, fewer punctures, less heat and better grip, and it became the standard for every passenger car.
How many materials are in a modern tire?
Over 200 raw materials, including natural and synthetic rubber, carbon black, silica, steel, textile cords and dozens of chemicals. Silica compounds, introduced in the 1990s, are what let a tire stay grippy on cold roads while rolling efficiently.
Posted by the Prince Tires team. Last updated: September 2026.
Sources:
Mental Floss – Why are tires black?
Michelin – The triumph of the radial tyre
Michelin Tire Digest – Tire materials
Model T Ford Fix – Model T Fords and clincher tires
Curbside Classic – The history of whitewall tires
