during the head gasket replacment that i had i noticed that the head was free from any oily deposits whatsoever so apparenty Mobil 1 was doing a good job in the engine.

now i am beeing told that Shell Helix ultra is better oil than Mobil 1 and i got to switch... is was even mentioned that it is the recommended oil for high performance cars as well as turboed cars... i know my car is nither high performance machine nor a turbo application but using it will make a difference for sure.

i was wondering what you guys think?? the Shell is almost the same price as the mobil so the performance is the only judging factor here and given those facts i mentioned, will i be better of using the Shell helix??
the Mobil 1 is rated at 0W 40 whereas the Shell is 15W 50 but i am not 100% sure of the difference here... does this mean that the Shell will lose more viscosity at the same temp. compared to the mobil?? in herer we worry much about heat rather than cold start issues and all.
need your advice guys.
MMamdouh