it’s the Abrams’ filters that might prove to be the biggest headaches for Ukrainian troops. Twice a day, an M-1 crew must rev its tank’s engine to high revolutions-per-minute in order to trigger a pulse-jet system that blasts air out of the tank rather than into it, shooting dust and debris from the back grille.

That keeps the filters clean across lengthy deployments. Before the Americans added the pulse-jet system to the M-1, in the early 2000s, tank crews—especially those fighting in the desert—openly complained about their vehicles’ reliability.

“Army officials are aware of the problems with high fuel consumption, unreliable fuel pumps and sand-ingestion,” the U.S. Government Accountability Office reported in 1992. “They are working on solutions.”

The solution to the sand-ingestion problem was the twice-a-day pulse-jet cleaning process. It works just fine, as long as crews rigorously adhere to its schedule. Even when they’re getting shot at.

"All those things can be taught to the crew, but if ever they make a mistake—and they will—it blows a million-dollar engine that can't be repaired in the field," Mark Hertling, a retired U.S. Army general

The Biggest Problem With Ukraine’s M-1 Tanks: They Don’t Like Staying Dirty

The biggest issue with Ukraine’s new fleet of 31 American-made M-1 tanks isn’t the tanks’ 1,500-horsepower turbine engines. No, it’s the filters in the engines’ intakes.

^{David Axe (Forbes)}