The SuperTouring rules were first introduced in an attempt to bring more variety to the BTCC. The championship, which had been dominated by the BMW M3 and Sierra Cosworth for the last couple of seasons, needed new blood if it was to flourish and grow in stature.

The 2 litre Touring Car Formula, as it was initially called, was created by two of the top BTCC engineers, Andy Rouse and ProDrive's someone else. Their concept was simple, to create a formula that would give new manufacturers the opportunity to enter the series and be able to compete against the more experienced manufacturers without the associated high costs of the existing Group A rules.

The changes would also give the rule makers the opportunity to turn the complex multi-class series into a single class championship, allowing drivers to win from the front rather than from within individual classes.

To achieve their goals, the rules targeted the type of car most manufacturers produced, a mid-range 4 door family saloon with a 2 litre normally aspirated mutli-value engine having a minimum production run of 2500 in one year. To enable the cars to be easily recognised on the track, the rules dictated that the car's body shape had to remain the same as the production model, but most other areas of the car could be modified specifically for racing.

Under the bonnet only the original engine block and head must remain from the production car but engine revs are limited to 8500 RPM to aid reliability and reduce costs. Racing transmissions and suspensions could be incorporated, but the suspension had to remain true to the original design of the road going model. Closer racing was also engineered into the rules by having different weight limits for front and rear wheel drive, and by limiting overall wheel and tyre sizes and by restricting each car to only 6 tyres per event.

The rules were first tried in 1990, as a supporting class for big Sierra RS500 Cosworths. Only Vauxhall and BMW works teams contested the class in the first year, but the racing was close and both teams scored wins. Privateer entries from Honda, Ford and Mitsubishi also featured, but were unsuccessful due to their limited budgets. The experienced ProDrive BMW team took the title with veteran Frank Sytner, but the fact that the Cavalier had managed to beat the all conquering M3 after only three races proved the rules worked.