Topic: Auto Tech: Exhaust heat recirculation

[Autos_Editor]

Introduced on the Toyota Prius and Lexus HS 250h this year, exhaust heat recirculation uses exhaust heat to warm the engine’s coolant, thus improving engine efficiency and fuel economy, and warming up the cabin faster.
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[Rupert]

It's possible that using the waste exhaust heat to heat the oil may produce better savings...especially in Canada where very cold air rushes by the oil pan and possibly cools the oil way below its optimum operating temperature thus creating higher viscosity levels and robbing HP and efficiency due to higher sliding friction.
I believe that racing motor cyclists used to pre-heat the oil at the start of a race to gain an advantage at the start.

[blur911]

What's old is new again.
My 25 year old 911 uses heat exchangers on the exhaust to heat the interior.  Cars have also had various methods of heating the intake for quicker starts forever.  Went away with injection, now I guess it's coming back.

[DavidC]

I seem to remember that VW(?) tried a heat storage system, possibly using a small vacuum-insulated tank in the engine bay, to store hot coolant from when the engine was last used, and to provide a rapid warm up, using some sort of heat exchange system.  I imagine the additional weight and compexity of such a system would not be insignificant.  I have noticed how much longer, under similar temperature conditions, it takes my CRV to produce any useful warmth compared to a friends Matrix which provides warmth very soon after start-up.

[blur911]

I seem to remember that VW(?) tried a heat storage system, possibly using a small vacuum-insulated tank in the engine bay, to store hot coolant from when the engine was last used, and to provide a rapid warm up, using some sort of heat exchange system.  I imagine the additional weight and compexity of such a system would not be insignificant.  I have noticed how much longer, under similar temperature conditions, it takes my CRV to produce any useful warmth compared to a friends Matrix which provides warmth very soon after start-up.

I don't remember the VW system, but Ford had a cold weather option with the insulated coolant tank you describe for it's trucks.

[Excidium]

If memory serves me right, I belive that your friend with the Matrix has a heating system that is electronically assisted. I remember in a previous article it was mentioned that the current generation Matrix has a heating electric heating element installed, factory, to assist with cold mornings. Just my two cents!