Residual Heat (REST) on MB cars

[Cmobile]

Just bought a 2003 MB CLK320 (88k miles) for a commuter car. Better than my suburban on gas. Small car, but comfy seats.

Has a cool feature on the climate control. Button labeled REST. It's a residual heat function that turns on a small electric cooling pump (I think) and runs the hvac fan on low to continue heating the car cabin with engine off, or key out. Helpful for a run into a grocery store on a freezing day to help keep the car warm.

However...
I'm thinking even in the summer after a spiteted run, or anytime when parking for a while, I turn it on to help cool the engine, just a schmekle faster. It automatically turns off after 30 minutes or when battery SOC is too low to sustain.

It would effectively recirculate engine coolant and extract the heat through the climate control. Would add heat to cab, but if I'm gonna be parked for a while, say, when I get home from work, the cabin heat will dissipate.

Any foreseeable downsides to using this feature on yhe summer?

 

[carviewsonic]

Additional heat on a summer day may be hard on the interior plastics, instrument cluster, etc. I'm surprised that the feature would be able to be activated if ambient temperature was above a set limit. Would be nice to have in the winter though.

 

[meep]

agree above, you could crack the windows open, but really - not much engine wear is attributed to heat soak, and MB blocks seem pretty stout. There should be hydrodynamic circulation within the block anyway to even the temps out internally. very cool feature; I’d love to have it in any of my vehicles.

 

[Falcon_LS]

You're better off just popping the hood IMO. The interior is going to roast in the summer when the car is parked, no matter what you do, and introducing more heat will not do the electronics and plastics, leather, etc. any good.

 

[2EHA]

the engine is indestructible why even waste your time

 

[Cmobile]

It literally takes 2 seconds... just depress a button.

Usefulness of running radiator fans after shutdown?

I'm wondering how useful continuing to run the radiator fans after shutdown as some vehicles do actually is at helping prevent heatsoak related problems. I understand that the coolant and oil temperature can rise significantly after shutdown since they stop circulating but keep absorbing heat...

bobistheoilguy.com

 

[Cmobile]

Not trying to cure anything.
Mostly thought it was a cool feature.
Pull in the garage, windows down, "press a button"
Circulates pump, low speed fan, what's not to like

 

[Skippy722]

No downsides, no real upsides either.