OK, I hate it when people ask me on group 5 oils. That is one I dread. It depends on what you are doing, racing, diesel etc.
Amsoil Series 3000 5w30 is heavy concentrated with Group 5. Amsoil 15w40 HDD&M are a blend of group 4 (PAO) and Group 5 (esters).
A group 5 is the best oil but sometimes it is not needed. Sometimes they are good for other fueled cars but not for weasels or gas. Sometimes the group 5 are great but the additives are low per say.
I have not talked about some Group 5 since I think they are over priced and you do not get more for the straight group 5. I would rather have a blend of both, 4/5.
Some groups 5 are: *A liter is not a qt , but smaller*
Redline (mostly ester with normal Lubrizal additives) $8 per qt
Amsoil 3000 (POA and Esters), $8.5 retail but dealer is like 20+% cheaper.
Motul 300v ($13 per liter)-poor shear though and low flash point
Fuchs Silkolene (no clue)
Neo ($8.50 per qt to $10 online)
Maxima (bike oil at $10 per liter)
Kemopro
VP racing ($10 per qt)
Castrol SLX 0w-30 ($18 per liter)
You can get any oil these oils online. The best bang for the dollar is Redline & Amsoil. There is no best oil for all applications. For roads car/trucks, these are the two I would select due to the price you get them for. I am not saying they are the best oils ever, but for the price, they are the best oil out there. Also must note most 100% group 5 are racing oils
The group 3 are ok oils, not the best. You will need to drain them sooner then group 4/5. Your B series will last 25 years with a group 3; however, you will get added protection/benefits from a 4/5. Also the jump up to a group4/5 is not much from a group 3.