We know that warming up a fuel-injected engine for an extended period of time is ineffective, causes unnecessary wear and raises your fuel consumption. But we also know from years of winter experience that there’s nothing worse than jumping into a frozen car on a cold morning. It’s a debate that will likely never be settled, but at least it makes for some fun visual science!
YouTube’s Engineering Explained decided to stick a thermal camera above a 2016 Subaru Crosstrek’s engine bay during a cold start at a frigid 22°F. By monitoring the engine speed and the temperatures of the coolant and the intake air, we can get a pretty good idea of what’s happening before the system gets warm enough for the ECU to drop the revs from 1800 to just 850 rpm. On this particular cold morning, this process takes more than six minutes, and while parts like the oil filter and the alternator are starting to reach their operating temperatures by then, your battery still remains as frozen as a popsicle.
Take a look, and you’ll have a better appreciation for just what’s going on under your hood on that first cold start in the morning. If it’s this chilly at 22, imagine what it’s like on those sub-zero mornings!