i know more oil controversy. here it goes, i normally use amsoil 20-50 having trouble getting it locally. i did find amsoil diesel syn 15-40 , i was ready to use rotella syn 15-40 but can't find that either... "small town"... has anyone used amsoil diesel??? in a pinch i just put in lucas 20-50 and i think it sucks, poor shifting and a little noisy.. also i do have cat pipes off a 2009 roadking any problems with the diesel oil there. any input would be appreciated. 2005 rsv baby