Nope Stu, you could have sniffed a little more and still nailed it. The thicker the viscosity the less chance of sloshing from G loads from accelerating, braking, turning and engine vibration simply make sence.
Even though all that is true about the recomendations for using a special #50 oil, every one of the shops that I worked in and hung around simply used the most readily avalable heavy earl!
That was back when oil bath air cleaners were common place.
Denny G
