right now im running ELF LDX 5w40 on my 2004 BMW X3. Compare to the M1 0w40 w/c i have also used before. The ELF is not noisy(valve clatter) during early morning start up and i got it cheap at my local auto store for $26.99 for 1 jug equivalent to 5 liters. I like this oil better but, unfortunately i dont have oil analysis data to prove it.