With super-cold temperatures in many parts of the country these days, drivers are tempted to let their engine idle and warm up for a long time before they hit the road. However, everyone should know that 30 seconds of idling is all your engine actually needs.
True, older cars that relied on carburetors did require to warm up to ensure a proper mix of air and fuel. However, today's electronic injection systems make idling unnecessary.
"The engine will warm up faster being driven," the U.S Environmental Protection Agency (EPA) and Energy Department explain. Indeed, it is better to turn your engine off and start it again than to leave it idling.
Natural Resources Canada conducted tests with three different vehicles at minus 18 degrees Celsius. Sometimes the cars were idled five minutes before driving, and sometimes 10 minutes. In all cases, the distance they covered was the same. The test results showed that with a 5-minute warm-up total fuel consumption increased by 7%-14% and with a 10-minute warm-up total fuel consumption increased by 12%-19%.
So, while it's more comfortable to enter a warmed-up car, remember that there are no other benefits and that you'll have wasted a non-negligible amount of fuel.