To most Canadian drivers, the ritual of letting their cars warm up a few minutes before driving is a time-honoured one. Although there’s the comfort factor of getting into a warm vehicle for that drive to work, the practice has come under scrutiny in recent years for its environmental impact. That’s because the advent of electronically controlled fuel injection has virtually eliminated the reasons drivers in decades past, so a prolonged warm-up basically wastes gas. However, that’s not to say there aren’t valid reasons for a brief warm-up in very cold weather – the most important being the circulation of oil throughout the engine.
In temperatures below freezing, oil can thicken up and flow more slowly, so it’s important the engine is warmed up sufficiently to ensure normal oil circulation— and it doesn’t take long. A good rule of thumb is the freezing mark: If it’s above freezing, no warmup is needed. If it’s below freezing, a minute or two is fine. Beyond that, you’re just wasting gas.