If you’re one of the six people who has wondered what would happen if you replaced your car’s motor oil with Coca-Cola and Mentos, prepare to be enlightened. That’s because one brave Russian decided to find the answer; it was not good.

Brilliant YouTuber , who recently put , did something even dumber (or, arguably, more brilliant) a few weeks ago: he stuffed a plastic bag full of Mentos under his car’s valve cover right against the timing chain sprocket, and filled the engine to the very brim with 21 liters of Coke:

“Everything is in perfect order,” the host says (translated from Russian by ). “Our baggy is in place, so is the battery. Now we try firing it up.”

But the engine doesn’t turn over.

So the host switches to another battery, but still nothing. After bumping the ignition a bunch of times, the engine eventually cranks over, and shoots Coke from its oil filler tube (likely due to the pistons pumping it out, not from the Mentos reaction):

“Sunova bitch! Start already!” the mechanic exclaims as the motor refuses to fire. But the old VAZ never springs to life.

According to the host, the cola’s low viscosity meant the soda made its way past the piston rings and into the combustion chamber, thwarting any chance of ignition. The wrencher drained some of the Coke onto the ground to try to reduce the chance of any getting into the combustion chamber, but by that time, the engine had seized up.

Which, if we’re honest, is not a surprising result. Coca-Cola isn’t exactly known for its lubrication abilities. So yes, this idea was as dumb as it sounded when you first read the headline. But I think it was definitely worth doing, if only to satisfy a curiosity I never knew I had.