Four-time F1 champion Alain Prost has returned to the wheel of a modern F1 machine for the first time in more than 15 years after sampling Red Bull's RB6 at Paul Ricard.

Prost was given the opportunity to complete a series of demonstration runs during the latest rounds of the Renault World Series at the French circuit, with Toro Rosso driver Jean-Eric Vergne also in action.

Vernge took the track on Saturday to complete his demo laps with Prost then in action on Sunday for what was his first run in an F1 car since a test with McLaren back in 1996.

"Overall, it's not so different to the last car I drove, which was in 1996, except that everything is obviously more perfect," he said. "It looks like we have improved in every department.

"Maybe the biggest difference, especially for me, is in terms of the ergonomics, how the driver is installed in the car. Your legs are very high and you only have two pedals and the clutch is on the steering wheel. You have to left-foot brake, which is very strange for me because I never did that before. There are a few things that feel different. But you feel that you can be quite well installed in this car."

Prost did however add that the car was a world away from the 1983 Renault he drove in a demonstration at the same event last year.

"I drove my car of 1983 at this track last year and that was really something strange: you really ask yourself how could we drive these kind of cars?" he said. "The gearbox in this car is fantastic and the engine is great in how the power comes in - it's very linear. I'm very impressed and quite happy to have been able to have been able to do this kind of test because it allows you to look at the current races and the work the drivers do in the different way. It's very useful to have the experience of these kind of cars, so thanks a lot to the team, I'm very pleased."