The German has surely secured the substitute drive in place of the injured Robert Kubica, who is facing most of the season on the sidelines.
Heidfeld underlined his quality, turning laps more than 1s faster than Vitaly Petrov achieved on Friday, finishing with a best of 1m 20.361s – against Petrov’s best yesterday of 1m 22.493s.
Bruno Senna is slated to drive the R31 tomorrow but it is hard to see the Brazilian matching Heidfeld’s pace and he hasn’t a hope of matching the veteran in terms of development experience.
Lotus Renault have clearly built a quick car: this is the second time in testing they have finished top of the pile.
Heidfeld can offer them the skills to work on the car and move it forwards and this is something the roster of near rookies simply cannot offer.
It remains difficult to make any real comparisons and we’ve seen several cars top the sessions – Schumacher managed it in the Mercedes yesterday.
The Pirelli tyres certainly look interesting, with big gaps between the compounds and steep degradation rates on the softer tyres.
The teams will be in Jerez for one more day tomorrow, before heading to Barcelona later in February.
A final test will take place in Bahrain ahead of the opening race of the season on the March 12/13 weekend. It’s arriving fast.