How Much Fuel Does Idling for One Hour Consume?
2 Answers
For an ordinary family car, idling for one hour typically consumes less than one liter of fuel, but this depends on specific conditions. Idling fuel consumption under different conditions: If the engine starts from a cold state, continuous idling for one hour will result in higher fuel consumption. Conversely, if the engine is already warmed up, idling for one hour will consume less fuel. However, during summer, using air conditioning increases the engine's load, leading to higher fuel consumption when idling for an hour with the AC on. Therefore, the exact fuel consumption during idling is influenced by many factors, including engine displacement. Estimated fuel consumption for one hour of idling: For a warmed-up engine, a 1.5L engine typically injects about 14 milligrams of fuel per cycle. Assuming an idle speed of 800 RPM, and considering that a four-stroke engine completes one cycle every two revolutions, 800 RPM idle speed equals 400 cycles per minute, or 400 fuel injections per minute. This results in a fuel injection rate of 5.60 grams per minute, leading to an hourly fuel consumption of approximately 340 grams (0.34 kilograms).
I've been tinkering with idle fuel consumption lately. Tested it on my own 1.5L compact car - with AC at max in summer, it showed 1.8L per hour on the dash. But there's significant variation between models; my friend's 2.0T SUV guzzles over 3L. Cold starts are the thirstiest, especially in subzero winter - the first ten minutes see instant consumption spike to 2L/hour, only dropping to around 1L after engine warms up. Car electronics are fuel hogs too - seat heaters add about 10% consumption. Converted to money at current gas prices, that's over ten bucks in boba tea money per hour. Best keep it under 20 minutes - saves fuel and reduces carbon buildup.
