Which technique works better in the cold?

[BeeUU]

My older car is not Scan Gauge compatible so I will not be able to test this my self in a decent amount of time, so I am hoping someone else has.....

While using allot of engine off coasting my engine almost never gets to full warm temperatures, so what is more efficient....

1) EOC with a less than warm engine or

2) Driving carefully with the engine running the whole time and warm.

Thanks in advance....

[Peakster]

That's a very good question. My scanguage turns off whenever I engine off coast, so I can't tell you for sure. All I know is that engines get better fuel economy when they're not running and the car is moving. Personally, I don't engine off coast until my 3 banger stops making it's 'whiny' noise when it's super cold out; usually around 50*F water temperature.

Also, my car only uses 0.2 gallons per hour at idle, so I would need to EOC for an entire hour (cummulatively) to save about a quart of gasoline. It's really hard to justify with my local terrain.

[lunarhighway]

here's my EOC experience...



all measured by filling up at the same station and whenever possible the same pump, over roughly the same trajectory...

give you're engine and oil some time to warm up, but if it will restart after being shut down it's you can start EOC.... don't exagurate when you're using a lot of heater/wipers/headlights... with the engine of all these things will run of the battery wich will drain quickly, and on top of that will be less charged than normal... if you notice your wipers operating slower and light shine more dim with the engine of it might be time to drive normal for a while....

driving with a cold engine gives bad FE
driving with a warm engine gives better FE
driving with the engine of gives the best FE

[cfg83]

Peakster -

Originally Posted by Peakster

That's a very good question. My scanguage turns off whenever I engine off coast, so I can't tell you for sure. All I know is that engines get better fuel economy when they're not running and the car is moving. Personally, I don't engine off coast until my 3 banger stops making it's 'whiny' noise when it's super cold out; usually around 50*F water temperature.

Also, my car only uses 0.2 gallons per hour at idle, so I would need to EOC for an entire hour (cummulatively) to save about a quart of gasoline. It's really hard to justify with my local terrain.

This makes sense to me. I think that you want to get the engine warmed up first, especially for the sake of emissions.

What I have noticed in my limited use of EOCing is that once the engine is warmed up, turning off the engine keeps the engine hot because the coolant stops flowing between EOC events. When I restart the engine, the coolant temperature will jump maybe 10 degrees F.

However, you may not experience this in aggressive EOC'ing, because the times that the engine is on aren't enough to keep it warm, (EDIT : right?!?!?!?).

CarloSW2

[rh77]

Originally Posted by Peakster

That's a very good question. My scanguage turns off whenever I engine off coast

Go into the settings of the SG and change the Fuel to "Hybrid" -- it'll treat the car as a gasser, but record the mileage as 9999 when EOC-ing.

RH77

[CO ZX2]

Originally Posted by BeeUU

My older car is not Scan Gauge compatible so I will not be able to test this my self in a decent amount of time, so I am hoping someone else has.....

While using allot of engine off coasting my engine almost never gets to full warm temperatures, so what is more efficient....

1) EOC with a less than warm engine or

2) Driving carefully with the engine running the whole time and warm.

Thanks in advance....

I had much the same problem as you have. I alleviated it by completely blocking and sealing all air at the front end of the car that could reach the engine compartment. In addition I fashioned a block underneath the engine from the front end back to the front wheels. In addition to that I put cardboard in front and behind the radiator. I also have had my electric fan switched off since last summer. In addition to that I added house insulation at the sides of the bottom of the engine compartment. Just keep it away from the exhaust and tie or wire it down. I have recently sealed the hood to fender gaps with adhesive-backed foam tape found in a hardware store.

Don't give up EoffC for anything else. You have seen the benefits. You have made sizable gains since you've been here.

[BeeUU]

Oh trust me I will not stop engine off coasting.....It is now part of my routine. Not to mention how much fun it is trying to anticipate traffic/lights/the idiot crossing in front of me/the grade of the road......it makes driving so much more interesting.

Last night during my trip of 45 minuets, the engine was off more than it was on, thus it never really warmed up to full operating temperature.

I have sealed gaps and covered the nose in tape, a belly pan is in work, but I have not gone as far as insulating the engine bay/radiator. My problem is that temperature fluctuates here (west coast) enough that I need a bit of cooling often enough that I remove tape to get air to the engine. Also, my wife drives the car in a more typical fashion, often in high traffic situations, and has forgot to plug the fans in a couple of times, I think the engine is alive only because of synthetic oil!!! There have been a couple of gushers!!

Thanks everyone for the help!!

[BeeUU]

Oh trust me I will not stop engine off coasting.....It is now part of my routine. Not to mention how much fun it is trying to anticipate traffic/lights/the idiot crossing in front of me/the grade of the road......it makes driving so much more interesting.

Last night during my trip of 45 minuets, the engine was off more than it was on, thus it never really warmed up to full operating temperature.

I have sealed gaps and covered the nose in tape, a belly pan is in work, but I have not gone as far as insulating the engine bay/radiator. My problem is that temperature fluctuates here (west coast) enough that I need a bit of cooling often enough that I remove tape to get air to the engine. Also, my wife drives the car in a more typical fashion, often in high traffic situations, and has forgot to plug the fans in a couple of times, I think the engine is alive only because of synthetic oil!!! There have been a couple of gushers!!

Thanks everyone for the help!!

[Peakster]

Originally Posted by rh77

Go into the settings of the SG and change the Fuel to "Hybrid" -- it'll treat the car as a gasser, but record the mileage as 9999 when EOC-ing.

I do have it set to Hybrid, but I don't have an engine kill switch. When I key off the engine and turn the key to the 'on' position the SG goes into sleep mode. Every once in a while (maybe once in every 25 EOCs) the scangauge will stay awake and show the 9999mpg.