EVERY gen-set I've ever had to hook-up used a circuit to pre-warm/ always keep warm the generator's oil and block.
Coming up to operating temps took virtually no time at all -- ever....
It was established that the gen-sets would be tested -- for real -- during the off hours -- i.e. the weekend by security -- by throwing a single double throw breaker.
No additional 'ttrick' loading gear was necessary.
As for engine efficiency ... no one gave a dang....
Since the gen-set was a freakish -- rare eventuality.
Some gen-sets were nat-gas powered -- but REAL emergency power was always diesel fueled. In the event of an earthquake - forget about pipes!
