Yep, I agree that M1 is loud compared to others. Why are some insisting on scientific proof? If you hear it, that's your proof. People on this forum know how their engines sound. They can tell when it quiets down or gets louder. The quietest oils for me are valvoline synpower, magnatec, and pyb. All 20 wts. Vehicles are 2011 elantra and 2013 civic ex.