Re: @LucreLout - But they do have glow plugs these days
The glow plugs are only used for starting and while the engine is warming up. I think you are confusing Diesels with semi-Diesels which have a hot region of the cylinder head to permit fuel burning at lower pressures than is needed by a true Diesel. And the glow plugs are there to initiate combustion, to to time it.
Biting the hand that feeds IT
