There are a few schools of thought when it comes to driving a car down a hill. Some people will leave a car in a higher gear and use the brakes, while others will rely on engine braking to maintain a constant speed. And, of course, there are people every which way in between.
But which method–neutral or engine braking–actually conserves more fuel while keeping you at a safe speed? You'd probably think that being in neutral was likely to give you better fuel economy, but that isn't necessarily the case.
Leaving the car in gear can actually use a lot less fuel than leaving it in neutral, since the computers need to inject fuel to keep it running in neutral, but not when the engine is spinning while the engine is braking.
Of course, that's a rudimentary explanation. For the full deal, check out the video from Engineering Explained.
Travis was an editor at Road & Track. He was previously the Editor-in-Chief of Jalopnik.com.
