I've got The Guzzler (1990/1991 Land Rover Discovery 3.5 V8 EFi) booked in for its MOT later today, so before it goes in I want to change the oil. But I don't know what oil it takes!? I assume 10W40 ? It has over 100,000 miles (infact it has 267,000 miles!) so I will have to use regular oil...