Not by my personal observation from having recently taken several long interstate road trips.
Not counting 18-wheelers (a pet peave of mine), the top left lane hog vehicles that I personally observed were...
1. Full-sized high trim level pickups (all makes)
2. Full-sized high trim level SUVs (Suburbans, Tahoes, Yukons, Escalades, Expeditions, etc... all makes)
3. German luxury vehicles
These were by shear numbers.
By percentage, it was German luxury vehicles #1 hands down, a small number of vehicles that ALL appear to hog the left lane. At least most of them were not going 10-15 mph under the speed limit.