I was just reading the post about stupid oil questions, when i recently got my disco the previous owner had been running synthetic. Should i change back to conventional on my next oil change? What brand is recommended for the 4.0l gas engine.

 

The purpose of running syn oil is (1) cold starts - you win the prize for that, and (2) in theory less wear and longer drain interval. Problem with that is usually the older technology Rover engine gets dirtier, and you need to change the sysn before the miles that could be done on something newer. A good oil to run above 14F is Shell RotellaT 15W40, widely available and a diesel rated oil, it has more cleaning compounds in it and will keep more gunk in suspension so the filter can grab it. Pix of a restricted oil pickup strainer, poor oil change issues, and example of Rotella at 180K, 3,000 mile drain intervals (Street Wolf). I'll take door # 3....

 

For your climate, use 5w-40 diesel oil all year, synthetic or not is up to you.

 

Shell rotella synthetic 5w40.