Coast before warm engine?

[GasSavers_Kraig]

A quick question about coasting with the engine off. Should you do this before the engine warms up as it prolongs the warm up time? Or should you wait until it's warm? It already takes my Festiva about 10-12 minutes to reach temp and I imagine it will be worse in winter (a case for an engine heater?). I'm not sure if the increased FE from coasting offsets the poorer FE while the engine warms up.

[krousdb]

My first EOC is about 10-15 seconds after I pull out of my driveway. Cold coasting It yields better FE for me than quicker warmup.

[MetroMPG]

Originally Posted by Kraig

(a case for an engine heater?). I'm not sure if the increased FE from coasting offsets the poorer FE while the engine warms up.

You said it: block heater is the answer. I used mine year round this year.

I can also say from experience that the hit from running the engine continually to warm it up will be much worse than the longer elapsed warm-up period from engine-off coasting.

But then consider this: people who practice CODFISHing generally only run the engine under load. It may actually actually warm up faster (based on amount of time running), vs an engine that is always on (including idling and no-load) for the first 10 minutes. The total elapsed time will be longer, but if you add up the running time, the CODFISHER may reach operating temperature sooner.

[Brian D.]

(off the topic)? Sorry, but I had to ask this since you made me think of it. A couple of years ago I had my CRX HF deep within the bounds of Yosemite Park. I was leaving the park to go out to dinner w/the little woman....about a 12 minute drive. When I left, the car quickly (normal) reached operating temperature. 99% of the drive after that was the way down the mountain, so I was just riding my (I dunno, 3rd?) gear LITERALLY the whole way down. (At the very foot of this was the restaurant I was going to). Well, from the time I noticed I was at operating temp (185ish), to the time I got to the restaruant the temp needle just dropped more and more. When I parked the car at the restaurant...no kidding...the needle was sitting on "C". Ice cold. How is this possible? I mean, if I'm in gear....isn't the car still firing cylinders? If my gearing is trying to slow the weight of me & my car from falling down the mountain, shouldn't that create heat/ a hot engine? I was surprised...and amazed. Was I burning ANY significant fuel during this drag down the mountain? Thanks, gurus, for any info.

[psyshack]

We as a X festiva owner. And a current sometimes hypermiler. I Coast ICE off right from the start. Our Festiva seemed to be slow on warm up. I never messed with the thermostat to see if this could be improved on. Come to think about it. I think I only changed the plugs once in it.

Wish they still sold that car here new. I would buy 2 ea. today.

[krousdb]

Originally Posted by Brian D.

(off the topic)? Sorry, but I had to ask this since you made me think of it. A couple of years ago I had my CRX HF deep within the bounds of Yosemite Park. I was leaving the park to go out to dinner w/the little woman....about a 12 minute drive. When I left, the car quickly (normal) reached operating temperature. 99% of the drive after that was the way down the mountain, so I was just riding my (I dunno, 3rd?) gear LITERALLY the whole way down. (At the very foot of this was the restaurant I was going to). Well, from the time I noticed I was at operating temp (185ish), to the time I got to the restaruant the temp needle just dropped more and more. When I parked the car at the restaurant...no kidding...the needle was sitting on "C". Ice cold. How is this possible? I mean, if I'm in gear....isn't the car still firing cylinders? If my gearing is trying to slow the weight of me & my car from falling down the mountain, shouldn't that create heat/ a hot engine? I was surprised...and amazed. Was I burning ANY significant fuel during this drag down the mountain? Thanks, gurus, for any info.

If you were going down hill in 3rd gear you were probably engine braking. Under that condition, Honda's usually shut off all fuel to the injectors. The only heat being generated was friction in the engine and transmission. if you had the heater on, that would be enough to cool the coolant significantly.

[rh77]

I know the success of FE depending on engine-off coasting, but has anyone (other than me) had any problems with the coolant/anti-freeze not sufficiently cooling or remaining homogeneous? I'm afraid to do it now that I've sprung a leak...

RH77

[JanGeo]

Just remembering what usually happens when an engine gets too hot and the driver turns off the engine . . . it boils over after the engine is shut off. Latent heat reaches the coolent but it is not being circulated when the engine is off - best to rev the engine a little to circulate the coolent into the radiator and maximize the heat exchange with ambient air. I still say unless you have a long coast to keep the engine running.

[GeoMetry]

In the winter you may need the engine to warm up just so you can see out the windows. You might want some heat in the passenger compartment as well. I didn't really get into engine off coasting until this spring so I don't really know how it works out in the winter.