McLaren's troubled MP4-30 suffered another Honda engine failure at Monday's Pirelli tyre test, ahead of its planned retirement from Formula 1.
McLaren is one of three teams helping Pirelli conduct wet-tyre testing at the Paul Ricard circuit over two days this week, along with Ferrari and Red Bull.
All three teams are using 2015-specification cars without any modifications.
For McLaren, that means the MP4-30 is being given another airing, with reserve driver Stoffel Vandoorne at the wheel.
Vandoorne still managed to complete 89 laps in a car that was using one of last year's Honda engines before he was forced to stop with a problem.
"We had an engine failure," he said. "The team asked me to stop the car, so that was the end of our day.
"All the teams are running last year's engines anyway. I don't know exactly how many miles were already on my engine.
"We were planning to change it overnight anyway, but unfortunately it broke at the end of the day."
On its return to F1 last season as power-unit supplier to McLaren, Honda encountered numerous issues that resulted in the team scoring a miserable 27 points and finishing a lowly ninth in the constructors' championship.