I'm a newbie, so apologies for asking the question that I'm sure has been asked a million times before...
Got a red top Astra GSi, and am wondering what you guys recommend - fully synthetic / semi synthetic, and any particular viscosity?
On my cossies, I found 0W/40 Mobil 1 to be too thin, and swapped over to 15W/50 Mobil 1 Motorsport, and I've got quite a bit left over, but don't want to sludge up the engine if they run better on the thinner stuff?
Also, the engine's done 130,000 miles - does the higher mileage engine need a thicker oil to protect those gaskets?
Any help much appreciated.