I didn't really notice it until I relocated the puke tank on my '01 Cummins, but right after an oil change it does have a weird smell. Kind of an acidic smell. It seems to go away after a while...maybe as the oil gets some miles on it.

I always run Rotella in my truck, but I use Valvoline VR1 race oil in my cars.

CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax