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Old 05-07-2014, 02:52 PM   #96 (permalink)
ctgottapee
EcoModding Lurker
 
Join Date: Nov 2012
Location: Midwest USA
Posts: 44

the old boat - '93 Cadillac Deville *removed/modified
90 day: 24.2 mpg (US)
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Quote:
Originally Posted by paulgato View Post
Hmmm... I always thought that the coolant preheater on its own would be better than an oil pan preheater on its own. But I think that both together would be even better than either on its own.

The Prius' idea of pumping the coolant into an insulated container while parked is great, but why not do the same for the oil? The oil already has a sump into which most of it falls when the engine stops, so why not insulate that sump from the air? One should be able to keep the oil warm for a couple of hours at least between drives. Also, an insulated sump would improve the efficiency of any oil sump heater fitted. The oil is cooled (in my engine at least) via a coolant/oil heat exchanger (aka 'oil cooler') so insulating the sump pan should present no hazard while driving. Maybe there is some kind of spray-on foam insulation that will withstand engine temperatures?
The oil sump is part of the heat emitting system, most cars have no oil cooler at all. The oil and its system is also designed for lubrication, not for heat transport. Even cars with a bit of oil cooling don't often use the old combined exchanger, which should probably be the first mod one undertakes as you get the full package of heating/cooling/stabilization.

Trying probably can't hurt, but it's not cost effective in comparison to the engine coolant. In a few seconds after that warm oil makes its first pass, it will have lost any benefit; remember the engine oil flows through a system designed to reject heat and in which heat is not a benefit. If the oil is too thick, you need a lighter viscosity.

Heck I've seen systems that try to pre-heat the fuel with warmed engine coolant; maybe it helps, but not likely.
You could even try pre-heating the tires, just like they do at the race track.
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