I know that the Priuses have small electric coil or maybe they are ceramic heaters to provide some cabin warmth until the engine temps are sufficient to provide heat to the cabin. Today was the first semi-cold morning (mid 40's) and the first time the Mariner wasn't garaged. After 13 hours sitting dormant in 40 degree temps, I had significantly warm air coming from the vents before I had even driven 5 blocks from my house. Just made me wonder if the Escape/Mariner Hybrids offer some kind of supplemental heat as well. Anyone come across this or see it in the shop manuals or anything? I find it hard to believe that any engine could provide substantial heat in that short a period of time.

 

Tim, I have heat before I leave the parking lot when I leave my workplace at midnight near Detroit, Mi. I have a scanguage and can see the water temperature rise quite quickly from ambient to around 130 degrees at that time. I do not start the car until I'm strapped in and ready so there is no pre-warmup time. I'd say that the design was for that result.

 

Of course I don't run my heater much, but the FEH does heat up quick. I was floored when I went closed loop in less than a mile with coolant temp at 140F and the CAT at ~600F. The outside temp was ~75F here when I tested.

Those that have a SG in colder weather may want to report the distance it takes to do the above also for this group.

GaryG

 

Yes... I wondered about that too when mine was new. This car gets cabin heat faster than ANY car I've ever seen. I have hot ( ok warm, 80-90'F ) heat coming out of the vents after one minute from a start at 32'F. Simply Amazing. I think this illustrastes that the heat goes to the cabin pre-radiator.
There is no electric heat.

Also, since this Hybrid has two radiators, and two closed coolent loops, each is on the small side. ( one for engine, one for electronics ) This means fewer quarts ( 3.7 ) and therefore less mass to heat up each time.
But also less heat "reservoir" to keep things hot when you are in EV mode.

In fact, my recent observations show, that running cabin heat at medium or high settings will cut ( city ) mileage just as bad as using A/C in summer. You wouldn't think so, but field testing over the road proves this. Based at 32'F running cabin heat at a medium blower speed will cause engine temp to drop 1 degree every 4 seconds. Take a 2 minute stop light, and the engine will cool 30 degrees! This is often enough to drop it below the set-point for EV and the engine will come back on, dropping your MPG like a rock.

But yes, it gets hot fast. One more reason not to let it idle in your driveway to "warm up". Those days are gone!

 

We also have to remember that the heater core is just a small radiator in and of itself. What I've read is that late model cars have a valve that bypasses the external radiator and just pushes the coolant through the heater core.... That heater core heats up very quickly and therefore so does the cabin air. After a certain coolant temperature is reached THEN the bypass valve closes and coolant is allowed to go through the external radiator as well.

 

If I'm not mistaken that valve is the thermostat which on the FEH is set @ 180 degrees F it will open and close as the water temp reaches that temperature. Not really a new inovation.

 

Maybe... The source I heard/saw said it was different than how it used to be done, but like I said all "late model vehicles do it". I'm not sure how "late" that would be.... for some reason I was thinking everything made after the 70's or so... but I'm not sure where that number came from.

In any case an engine pouring all its heat into a heater core ONLY is going to get that heater core HOT fast.

 

Bill, I just posted the other day about a separate heater pump that comes on when the climate control switch is in any other position other than off. It was for this reason I recommended leaving the system off completely, or at least after your able to go EV. Since there is a heater pump, coolant must not be able to circulate unless it is on. The other reminder would be, if the pump is running, your using 12V DC current that must be replaced at a small decrease in MPG. For this reason, and the fact that you can go closed loop and EV quicker, I would keep it off as much as posible, even during the summer.

One thing I want to add for the reason the FEH can heat up quicker than most cars, is that remember how the Atkinson 5 cycle works. It dumps a small amount of heated air mixture back in the intake manifold on the combustion stroke. This has gotta help the FEH's FE over the otto cycle which sucks in only the cooler air in. It may be another good reason to buy and drive a hybrid in cold climates.

GaryG

 

Sorry, no.

Engines using the modern day implementation of the atkinson cycle leave the intake valve open for a portion of the COMPRESSION stroke resulting in about 30% of the A/F charge in the cylinder being ejected back into the intake manifold, therefore NOT heated by the process of compression.

That does result in more of the explosive, heat energy of the A/F mixture being used up during the power stroke, in the process of moving the piston out of the way of the flame front, and therefore more heating of the engine, not as much heat escaping into the exhaust manifold.

Which is why you will never see an Atkinson engine with a turbo.

 

Willard, where did I say heated by the process of compression? Certainly you agree that the 30% of fuel mixture that you estimated is warmer than the fuel mixture that did not have contact with the hot combustion chamber? Add that constant 30% being pushed back in the intake manifold and you have a much warmer A/F mixture than the otto. That's all I said.

The same issue of a warmer A/F mixture during partial throttle is why it's more fuel efficient than WOT, but we both know we disagree on that issue also.

GaryG