“Close only counts in horseshoes and hand grenades,” the saying goes. BMW has taken that expression to a whole new level. According to The Drive, BMW took a fuel cell powered X5 and tested the structural integrity of its hydrogen tank protection by blowing up a grenade under it. Seriously.

It’s only slightly less crazy than it sounds. There was no actual hydrogen in the tank when they tested it, so if the tank was pierced, there would be no earth-shattering kaboom. But still, that’s pretty extreme measures.

The best part is the tank survived, completely intact, because the armor did its job.