Let's say you're cruising down the highway. The car in front of you slows, and you change lanes to pass. Should you downshift, or leave the car in gear and stomp the throttle? Well, if you want to protect your engine, you should definitely downshift. Here's why.
Driving at full throttle with the engine at a low RPM because the transmission is in too high a gear is known as lugging your engine. And while it's bad for naturally aspirated engines, it's even worse for turbocharged ones.
At the most basic level, lugging your engine doesn't make much sense because it puts your engine at a disadvantage. That means it has to work harder to do the same amount of work. But that also means it runs less efficiently, increases engine temperature, and can even cause issues with the engine's timing. With a turbocharged engine, you also have to worry about low-speed pre-ignition, a phenomenon that can damage spark plugs or even crack pistons.
For a more in-depth explanation of how all this happens, check out the above video from our friend at Engineering Explained. And remember, if you need to accelerate, go ahead and downshift for the good of your engine.
