Liqui Moly 1092 MoS2 low friction oil 10W-40 5 liter (Automotive)
when I saw a vintage car with 3 liter boxer engine at the rear acquired several years ago, I was not sure which oil for 1981, he is the right engine. Specifying the automaker was succinctly a 10W40. After I read of many well-known manufacturers, the