Fernando Alonso's first drive in Renault's new F1 car took place at the Cheste Circuit in Valencia, Spain.
Alonso's first drive in the 2008 Renault was delayed by fog
The former world champion completed 39 laps in the R28, after setting some of the quickest times in the 2007 model during testing a week earlier.
"Everything went well but it is still too early to try to compare our performance with that of other teams," said Alonso.
"That wasn't the objective and the good news is we encountered few problems."
Around 4,000 fans were in a foggy Valencia to watch the Spaniard with 20,000 expected to watch during the three-day test.
Renault, third last season after winning the 2005 and 2006
championships, will launch the new car in Paris on 31 January.
"The car ran pretty much trouble-free, that is about as good a first day as you can expect with a new car," said chassis technical director Bob Bell.
All 11 Formula One teams will give their new cars a run-out from Tuesday.
The 2008 Formula One season starts in Australia on 16 March.