OK, another way to approach this - what the heck is all that higher viscosity oil being used for?
Plenty of 10W40, 15W40, 20W50 for sale...are there any cars that aren't calling for 5W30 or 10W30? Or are people just ignoring that and using heavier oils like always used to be the case?
So, if you disregard the manufacturer's concerns on meeting fuel economy standards -
I should still be using the heavier oils at higher temperatures for the best mechanical protection?
In the past, I frequently saw API temperature/viscosity charts in auto repair books. These charts showed which engine oil to select based on the range of temperatures where you were doing the driving.
Back when I used to see these charts, 10W40 oil was very popular. Many of the charts...
Without knowing the details of part shapes, area layout, etc., it's tough to recommend a solution.
But, you might consider :
1. Delivering & removing parts at the right "altitude" - so they do not have to be lifted
2. Eliminating lifts by using ramps/slides so workers can slide parts where...