With the help of Elf and Ford, Tyrrell then achieved his dream of moving to Formula One in 1968 as team principal for Matra International, a joint-venture established between Tyrrell's own privateer team and the French auto manufacturer Matra.
Stewart was a serious contender, winning three Grands Prix in the Tyrrell-run Matra MS10.
The car's most innovative feature was the use of aviation-inspired structural fuel tanks.
These allowed the chassis to be around 15 kg lighter while still being stronger than its competitors.
The FIA considered the technology to be unsafe and decided to ban it for 1970, insisting on rubber bag-tanks.

For the 1969 championship, the Matra works team decided not to compete in Formula One.
Matra would instead focus its efforts on Ken Tyrrell's 'Matra International' team and build a new DFV powered car with structural fuel tanks, even though it would only be eligible for a single season.
Stewart won the 1969 title easily, driving the new Cosworth-powered Matra MS80 which corrected most of the weaknesses of the MS10.
Stewart's title was the first won by a French car, and the only one won by a car built in France as well as by a car entered by a privateer team.
It was a spectacular achievement from the British team and the French constructor that both had only entered Formula One the previous year.
With the help of Elf and Ford, Tyrrell then achieved his dream of moving to Formula One in 1968 as team principal for Matra International, a joint-venture established between Tyrrell's own privateer team and the French auto manufacturer Matra. Stewart was a serious contender, winning three Grands Prix in the Tyrrell-run Matra MS10. The car's most innovative feature was the use of aviation-inspired structural fuel tanks. These allowed the chassis to be around 15 kg lighter while still being stronger than its competitors. The FIA considered the technology to be unsafe and decided to ban it for 1970, insisting on rubber bag-tanks.
For the 1969 championship, the Matra works team decided not to compete in Formula One. Matra would instead focus its efforts on Ken Tyrrell's 'Matra International' team and build a new DFV powered car with structural fuel tanks, even though it would only be eligible for a single season. Stewart won the 1969 title easily, driving the new Cosworth-powered Matra MS80 which corrected most of the weaknesses of the MS10. Stewart's title was the first won by a French car, and the only one won by a car built in France as well as by a car entered by a privateer team. It was a spectacular achievement from the British team and the French constructor that both had only entered Formula One the previous year.
Tyrrell Racing