Formula 1 is nothing if not dynamic. Every now and again, the Powers that Be decide to shake up the rules in a big way. This is inevitably followed by a large spike in exploration to see who can best leverage any advantage to be found in the new sporting regulations. From those bigger chunk explorations, a leading approach arises, which drives others to replicate, refine, and improve upon the original premise. We know the successes, but we can also see the historical trail of tried and abandoned innovations. Lotus attempted four wheel drive to find better grip when power increased, but aerodynamics won out. Brabham tried to bring Jim Hall's Chaparral vacuum car technology to Formula One, but ultimately it was nullified. And in 1976 Tyrrell debuted their well known six wheel car.
The Tyrrell is probably the best known formula car with more than four wheels, but it was far from the only one. In the mid to late 1930s, teams such as Auto Union and Mercedes attempted to use four rear wheels as an attempt to improve traction. And in the same timeframe as the Tyrrell P34, Ferrari was also experimenting with the 312 T6 six-wheel car. Ferrari actually showed images of a prototype 8 wheel drive car as well!
The thinking behind the Tyrrell's smaller front wheels was initially driven by cleaning up aerodynamics. They knew they were at parity at best on power, so needed some form of competitive advantage. Derek Gardner, Tyrrell’s chief designer at the time, had already floated the six-wheel idea to Andy Granatelli’s Indy Car team several years earlier, but they didn’t proceed with it. Gardner knew exposed tires are very disruptive to airflow, so the thinking was that, by using 10 inch diameter wheels, the tires could be tucked neatly within the bodywork and air flow of the front end. They were also aware this could create a favorable mechanical grip equation with more contact patch to the ground, as well as provide more swept brake surface.
It didn't take long for one of the flaws in the Tyrrell thinking to surface. While they had improved aerodynamic disruption around the front tires, they still had very large, exposed rear tires. The experiment wasn't producing the significant aero advantage as planned. They were not able to keep pace with aerodynamic innovations by other manufacturers on the higher speed tracks. On lower speed tracks, however, the added front mechanical grip did prove to be a measurable advantage.
In the tight confines of Monaco, the Tyrrell managed a second and third-place finish over cars that were considered much faster in a straight line.
The next race In Anderstorp Sweden, which was comprised of many intermediate speed corners, they surprised everyone by backing up their success in Monaco with a very strong 1-2 finish.
Unfortunately, the Swedish 1-2 appeared to be a fluke. While the P34 did wrangle 6 more second-place finishes in 1976, that was as good as it would get for Tyrrell. In 1977, they cleaned up the aero on the P34's body, but tire development was advancing against them. It was getting difficult to get the manufacturers to develop appropriate tires for their unique scenario, and definitely not at the same pace as teams that used more common sizes. Additionally, Lotus was really advancing with ground effects, and finding results. That may have been the fatal blow for the four-front-wheel concept. The ground effects concept wanted as much free-flow air under the chassis as possible, and the added front tires were now taking up valuable real estate.
Ultimately, between Lotus advancing under -car aero and Renault determining that a 1.5 turbo could create more power than the DFV 3.0 liter, the Tyrrell P34 was dropped after the 1977 season. In 1983 the FIA prohibited cars with four wheel drive, then later required the maximum number of wheels allowed at 4.
There is no question the Tyrrell is one of the most identifiable cars in F1 history. Some have called it the most recognizable design in the history of world motorsports. It continues to entertain people, and makes regular appearances at historic events.
With every passing year, teams will continue to find that big, paradigm-shifting advantage. As the rulebooks get thicker, and more restriction get layered in, the chances of seeing something break through as dramatically different as the Tyrrell P34 get increasingly less likely.