Heidfeld (centre) was part of an all-German line-up at Mercedes, with Nico Rosberg and Michael Schumacher
Mercedes have released reserve driver Nick Heidfeld from his contract to become Pirelli's tyre test driver.
The 32-year-old stepped down from regular racing at the start of the season after 10 years in Formula One.
"We are confident Nick's knowledge and feedback will prove extremely useful to Pirelli and benefit the sport as a whole," said Mercedes boss Ross Brawn.
Pirelli will replace Bridgestone as the sole tyre supplier in 2011, returning to F1 for the first time in 20 years.
Brawn added: "Nick has been a real asset since joining our team and we are pleased to see his career progressing."
Heidfeld will use last year's Toyota's F1 car, the TF109, to test the tyres all the teams will use.
The TF109 has been chosen as it has contemporary technology and performance with which to give the tyres the best possible test but it will not give an advantage to any current team as Toyota are no longer in the sport.
Following Heidfeld's on-track development work, all the current F1 teams will have the chance to work with the new tyres after the 2010 finale at Abu Dhabi in November.
Heidfeld's consistent performances in his racing days are one of the reasons Pirelli moved to sign him - he holds the record for the highest number of consecutive race classifications, 41.
"We're delighted to welcome Nick into the Pirelli family and we're confident that he'll do a great job for us," said Pirelli Motorsport director Paul Hembery.
"The role of test driver is crucial so we were looking for a driver who had plenty of recent F1 experience, the speed to push our new tyres as hard as possible and the consistency to provide reliable simulations as well as the analytical skills to relay information accurately to our engineers.
"Nick fits the bill in every respect."