Here’s the worst advice you’re going to get today: If you want to get more power out of your engine for free, drain some oil. Apparently a combustion engine runs more powerfully when there is less oil in it. In a video from The Motor Oil Geek you can see that a large V8 gains almost 10 percent power by halving the oil level. We repeat again: this is bad advice.

These guys have a V8 on the test bench. To start with, they throw five liters of oil into the engine. High in the revs they see that the power reaches just under 650hp, but they do see that the oil pressure takes a dip. Logical, because there is too little oil in the engine. That’s why they throw an extra two liters into the engine for the next run.

The engine produces just as much power at the lower revs. At 6,400 rpm the difference is clear: the two liters of oil cost the engine about 16hp. Here too, the oil pressure is not yet completely healthy. That’s why they add another two liters. With nine liters of oil the pressure remains constant, but it does require a lot of power: at high revs the engine loses 60 hp!

The oil collects at the bottom of the engine and the crankshaft hangs just above it. According to the video, the reason behind the decreasing power is that the crankshaft has to move through the oil. This extra resistance costs power. On the other hand, your engine will last a lot longer with the correct oil pressure: the loss of power is therefore a necessary evil.

We dare not say how much power you will gain by draining your oil. It will differ per engine. But again, your engine really appreciates having enough oil, so make sure you have enough oil in the engine to maintain your oil pressure!