With the help of Elf and Ford, Tyrrell moved to Formula One in 1968.
He started as a part of Matra International.
It was made up of Tyrrell's own team and the French auto maker Matra.
Stewart was expected to race very well.
He won several Grands Prix in the teams Matra MS10.
The car's most unusual feature was the use of aviation-styled structural fuel tanks.
These let the car to be around 15 kg lighter.
Although it was lighter, it was still stronger than the cars it was racing against.
The FIA thought that the technology was not safe.
They chose to not let it be used in 1970.
They said that rubber bag-tanks had to be used instead.

For the 1969 championship, the Matra team chose to not compete in Formula One.
Instead of competing, Matra worked with Ken Tyrrell's 'Matra International' team.
They built a new DFV powered car with structural fuel tanks, even though it would only be able to be used for a single season.
Stewart won the 1969 title easily driving the new Cosworth-powered Matra MS80.
Stewart's title was the first won by a French chassis.
It was the only one won by a chassis built in France.
It was a very special event for a team and a constructor that had only entered Formula One the year before.
With the help of Elf and Ford, Tyrrell moved to Formula One in 1968. He started as a part of Matra International. It was made up of Tyrrell's own team and the French auto maker Matra. Stewart was expected to race very well. He won several Grands Prix in the teams Matra MS10. The car's most unusual feature was the use of aviation-styled structural fuel tanks. These let the car to be around 15 kg lighter. Although it was lighter, it was still stronger than the cars it was racing against. The FIA thought that the technology was not safe. They chose to not let it be used in 1970. They said that rubber bag-tanks had to be used instead.
For the 1969 championship, the Matra team chose to not compete in Formula One. Instead of competing, Matra worked with Ken Tyrrell's 'Matra International' team. They built a new DFV powered car with structural fuel tanks, even though it would only be able to be used for a single season. Stewart won the 1969 title easily driving the new Cosworth-powered Matra MS80. Stewart's title was the first won by a French chassis. It was the only one won by a chassis built in France. It was a very special event for a team and a constructor that had only entered Formula One the year before.
Tyrrell Racing