To those with an EBH installed

My guess is it was related to the SOC of your battery. When you start your engine you have a tendency to use the battery during S1-S3. When you got to S4, you likely didn't have at least 5-6 bars, and thus you were not able to glide just yet.

 

<div class='quotetop'>QUOTE(treehggr @ Aug 21 2007, 09:12 AM) [snapback]499711[/snapback]</div>

To give you an idea if I heat it for 2 hrs and the outside temp is about 15C it will heat it to about 35C. The car will glide at 40C so it take about a hundred yards to reach. It is summer in the UK so how it will perform in the winter will be interesting to see. I use a ScangaugeII to see the engine temp.

You will need a reasonable SOC. 3 bars plus

 

I have noticed that with the block heater, after getting to S3/S4, it is best to get a little time, 1-2 miles, above 42 mph to put a charge on the battery and then drop back to the below 42 mph route. The battery charge doesn't cost much fuel, the ICE is pretty efficient at ~50 mph, and afterwards, I can let the hybrid control laws handle cycling between ICE and EV with excellent MPG.

Bob Wilson

 

<div class='quotetop'>QUOTE(gazz @ Aug 21 2007, 08:43 AM) [snapback]499735[/snapback]</div>

That is very interesting.
I cannot get into a glide until the engine reaches 50C (122F) and the Air intake temp is at 25C or higher. I too use a ScanGauge II to read the temp values.

Cheers;

MSantos

 

<div class='quotetop'>QUOTE(treehggr @ Aug 21 2007, 05:20 PM) [snapback]500026[/snapback]</div>

try this with the engine block heater installed:

start car, let it run the engine in park (i recommend with parking brake if you want to save 140 watts and not turn on the DRL)

as that's happening unplug your EBH, by the time you get into your car the car should be in S3 mode (since your coolant should be around 50 degrees C unless you plugged after a hot start)

NOW someone ask me (uh isn't it stupid to let the engine idle while not moving? your getting 0 miles to the gallon or 0 km/L) but the problem is, when the engine starts up the first time, it uses most of its energy from the battery because the engine has to "do its thing" before it can provide any motion power to the wheels, by the time the engine is done you have used a lot of juice from the battery already (unless you went really slow like 20 km/h) its time for payback aka CONVERSION LOSSES IS A BIG NO NO. But as soon as you hear the engine die in P for the first time, take heart your engine will provide motion power! For those without a EBH this idling time is increased, but for users with its only a mere 20-30 seconds or less even on hot days.

pulse (use engine when most efficent)

glide (hit the ev mode switch but keep it below 54 km/h or else you will be forced to glide with the engine on until you get back down to 54 km/h again.)

when engine coolant surpasses 70 degrees C you may begin to pulse and glide at higher speed intervals (64km/h tops instead of 54 km/h tops) since after 56 km/h letting off the gas pedal goes into "stealth" mode or "temporarly EV mode until you press the gas pedal too hard, although i find interesting in pure EV MODE that gas press needs to be harder!"

just use the engine when its most efficent ( for NHW20 i find between 1500 rpms and 2300 rpms, keep SOC above 55% to avoid conversion losses (engine power to battery power is a NO NO, try to focus engine power to the wheels at all times and leave the charging to the slowing down to a stop or hills).

 

When you start your Prius in the morning, try not to use the accelerator, just let the car coast to the first stop light, it will do so at about 1280 RPM/1312RPM. If you can, stay on the gas as little as possible, but keep the ICE going, until you hit that main road (whatever the heck the name is). When you stop at the main road you should feel the auto stop into stage 4, your SOC should be up and you can glide.

And remember, if you want into the 70's (MPG) stay out of that battery.

Wayne

 

<div class='quotetop'>QUOTE(MSantos @ Aug 21 2007, 02:31 PM) [snapback]499877[/snapback]</div>

I can defiantly get into glide at 40C, the only thing is that it seems to need a certain time, so if you use a block heater that gets it to nearly 40C it seems to need a few hundred yards of driving. I find getting the block heater to heat to about 30-35C seems to give the engine the time to settle down and then glide at 40.