gt4awd

Decided to change it up a bit, and try some Castrol. After 5,500 miles I was getting additional vibration from the engine. Upon doing an oil change the Syntec had a burnt smell to it... Wouldn't recommend at all! Nice, and smooth after switching back to Mobil-1 0w40..

03MBC32

I changed the oil with Mobil 1 0W40 in June on the wife's 06 BMW 323 (Canadian)which had Castrol 5W40 since new. She knows nothing about cars. After a week she tells me the car runs a lot smoother.

TemjinX2

i dont get why you would want to put a thicker oil in a engine with such tight tolerances.

gt4awd

There is no 0w40 Castrol, and I've heard a slightly thicker oil is good on higher mileage engines.