warm up fuel consumption rate

I haven't seen GenII numbers, but several of us posted GenIII numbers in What is the fuel consumption of the Gen 3 when the ICE idles? My numbers are in posts #5 and #13. This should get you close.

 

I measured my 2009 with ScanGauge: ~0.83 GPH during S1A. Good luck!

 

I saw it start at 3 l/hr then immediately drop to 2.5 within a few seconds, continuing to drop to 2.2 over the next 15 seconds, then after about a minute, drop to 1.3 l/hr. Once "warm" (coolant over 43C) it uses 0.85 l/hr at idle. The engine would be off except the heater (A/C) is demanding heat so it runs until the coolant gets above 64C. Eventually this drops to about 50C for engine trigger.

 

It's 3.8. Use Online Conversion - Convert just about anything to anything else to convert.

 

I also made a really small stand-alone unit converter application that I uploaded to the file library a while back. If anyone wants it its still there :
http://priuschat.com/forums/file-library/69451-simple-fuel-consumption-converter-calculator.html

 

I do not warm up my Prius on a cold day. I take my first mile out of the neighborhood nice and easy and just go do my normal driving. The engine warms up fast, IMO.

 

According to Japanese hypermilers the reason for warming up the engine with the car still in park is that during S1A the engine provides zero power to the wheels and the fuel is completely wasted unless it is allowed to charge the HV battery with the car still in park. Hope this helps.

 

Regardless of it's impact either way on fuel consumption I've found it's definitely worth giving it a short warm up if you're starting cold at the bottom of a sizable hill. This really seems to reduce the strain on the HV battery (and probably also the engine). I used to always drive straight away but changed my way of thinking after realizing just how hard you're pushing the HV battery when you take off up a hill from cold, since the engine does almost no work and the battery/electric motor does it all.

If I can drive slow on flat terrain for the first 30 to 60 seconds then I'll definitely drive off immediately, but if I've got to drive hard or up hill straight away then I let it warm for a little while in park. I usually only wait until a bit after I first see the green arrows into the battery, about 10 to 20 seconds after that I drive off. This it seems to make a big difference on how well the battery maintains it's state of charge.

BTW. You've got to be in "park" if you warm up like this, otherwise you don't get the idling engine charge the batteries. At least not that I've ever seen.

 

my consumption of fuel during the S1 to external temperature
+14 °C = 0.073 ml
Outdoor temperature of +7 °C The consumption of fuel during s1 = 0.096 ml

http://i.imgur.com/sjRWD.png

 

Yep the above poster used the wrong units. It should be L instead of mL (one thousand times more than shown).

 

How long do these guys let it idle before engaging drive do they just wait till the motor turns off then go?

 

If you have ScanGauge you can watch IGN change from -10 to some positive number, if not then just listen for the engine sound change when the car finishes S1A, then shift out of park and go. Hope this helps. Good luck!

 

And, the S1A lasts approx 1 minute from the initial start.

Ken@Japan

 

Thanks! And with an engine block heater it can be shortened to ~ 20 seconds.