I don't remember what happened to the 6 wheeler. I know the theory was with 4 front tires, they could be lower profile, therefore less wind resistance and still put more rubber on the asphalt than traditional sized front tires. They finished in the points (and back then it was only the top 6) 20 times in 16 races. They placed both cars in the points 6 times. They only won 1 race (Sweden) but they finished second 8 times. It was enough to finish 3rd in the constructors championship.
Here's what I found on the 6 wheeler.
The Tyrrell P34 (Project 34), commonly known as the "six-wheeler", was a Formula One (F1) race car designed by Derek Gardner, Tyrrell's chief designer.[1] The car used four specially manufactured 10-inch diameter (254 mm) wheels and tyres at the front, with two ordinary-sized wheels at the back. Along with the Brabham BT46B "fancar" developed in 1978, the six-wheeled Tyrrell was one of the most radical entries ever to succeed in F1 competition and has been called the most recognizable design in the history of world motorsports.[2]
The P34 was introduced in September 1975 and began racing in the 1976 season.[1] It proved successful and led other teams to begin design of six-wheeled platforms of their own. Changes to the design made for the 1977 season made it uncompetitive and the concept was abandoned for Tyrrell's 1978 season. The other six-wheeled designs ended development and F1 rules later stipulated that cars must have four wheels in total. The existing frames have since seen some success in various "classics" race events, but today are museum pieces.
So it was banned but only after it became non-competitive and scrapped.
I loved those "old days". Sure it was more dangerous for the drivers but the racing was so much more competitive from top to bottom. I remember the Brabham team finishing 1-2 at the Glen in 1974. Carlos Reuteman and Carlos Pace were the drivers. James Hunt finished 3rd in his Hesketh. That was a classic car because when it hit the scene in 1974 it had absolutely no advertising on it. That same year, a couple American teams competed at the Glen. Gurney had a team with Mark Donohue at the wheel and Parnelli Jones had one with Andretti driving. Neither did well.
The Glen was such a great experience. You could watch practice on Thursday and Friday, then go to the Paddock area and watch the mechanics working on the cars. Many times the drivers were right there. I stood just feet away from Jackie Stewart, Graham Hill, Jacky Ickx, Jody Scheckter (who in his youth was disliked by other drivers because of his recklessness; but we all loved him), Niki Lauda, James Hunt, Emerson Fittipaldi, Jacques Lafitte and many more. I remember the morning of race day 1974, as we were walking around the grounds, Graham Hill almost ran us over arriving at the paddock. It was a great experience.
Either of you guys ever hear about "The Bog" at the Glen?