How's your idle? (Just some idle blabbing)
 

Just wondering about the rpms and fuel consumption of different engines while idling. Share your data, and please give info on the car and it's engine.

My Peugeot 307sw has a 1.6 liter HDi turbodiesel engine with 80kW (110hp). It idles @ 820rpm when rolling and 740rpm when stopped. When warmed up (coolant temp 80°C/176°F) the fuel consumption is 0.60 lph (0.16 gph) while rolling and 0.52 liters (0.14 US gallons) per hour at standstill.

Above data is from my uncalibrated SGII. Outdoor temperature 18°C/64°F. Electric load: LED DRL's (11W total), ventilation fan (speed 2 of 8), CD player.

I've noticed that the per hour consumption can increase by as much as 10% just by pressing the brake - could this be only from the added electrical load of the stop lights (55W total), or is the brake assist adding a load to the vacuum pump on the engine?

2000 Honda Insight 1.0L L3. 0RPM/0gph once warm. 900-1100RPM if you interrupt the auto stop. The ScanGauge says something like 0.11gph at idle, but it is extremely poor at measuring the fuel consumption of my car. But I suppose I should go get an accurate reading of fuel consumption at idle by rolling down the road at 15mph with the engine idling and checking Honda's instantaneous FE readout.

I've seen other cars where pressing the brake raises the idle. I bet it's vacuum related, but you can test by turning on the headlights to create a 110W electrical load.

My last car was a 1996 Subaru 2.2L. 0.24-0.26gph, 800RPM.

Heh, Robert.

My Civic is about 0.35 gph idling, which it does almost never.
The 3.5 V6 Odyssey is 0.5 gph, or 0.6 with AC on.

My 2002 Mitsubishi Galant 3.0l v6 is .34-.36 gph in neutral, warm per SGII
The Wife's Ht Rd is .5 GPH warm per OE computer. Never checked w/SGII.

The increased consumption is most likely mostly the vacuum required to be produced not the electrical load.
You could disconnect the brake switch and see if it changes.

The Ford engine 4.0 litre six cylinder non diesel , VVT and variable intake manifold uses a between 1.5 and 2.0 litres at idle (850 rpm) in neutral for the manual variant.
Info from Ford in a release about the then "New" engine (2008 I think) and still in production.

Pete.

darn this question.
I can't even measure fuel mileage.. unless I underestimate, and that is still ok I guess.

if my voltage regulator for the alternator allowed 250 rpm I would let the old sube go there. Very content. I have bogged it to 50rpm waiting for a kick in return...I can only guess they keep it like other cars to be sounding normal, like 500-750, and make the alternator function correctly. Else, I could really set it down..

The consumption is indeed low, I camped all night in one at 0F, (needed idle for heat).. hardly an 8th guage down for 8-10 hours.

1781cc, progressive 2 barrel, 3 main boxer.

Piwoslaw -

At idle, ~850 RPM = ~1.05 LPH = ~0.28 GPH at standstill.

CarloSW2

0.11gph is pretty darned close to correct. The instantaneous fuel consumption gauge crossed 100mpg while rolling through a parking lot at 10-11mph (0.10-0.11gph).

I was referring to the 0 rpm 0 gph part. ;)

1.5L Mazda Protege. 775rpm and 0.19gph. But I think I had my foot on the brake and clutch out in nuetral. I'll try tonight with clutch in, E-brake on and minimum electrical load.