Of the three proposed answers in the multiple-choice question of source text, the 'correct' one is most probably 'break in oil' (huile de rodage). If it's not that, then it's the standard oil for diesel engines: 10W50 oil.

So, the third option 'wear in oil' is the 'joker' in the pack of answers. And of course the term does not exist...

I suggest you put something (almost anything...) that might seem plausible to incompetent answerers but is obviously 'stupid' for those who have done their homework.

As it happens, I know someone who really did use 'huile d'arachide' in a newly-rebuilt engine - in the (mistaken) belief that it would 'loosen up' the new crankshaft bearings. It did - so much so that he spent the next weekend rebuilding the engine again ...