If you’re a Cummins fan, you may have memorized the stats of the six-cylinder 6BT offered in heavy-duty Ram trucks. But did you know that Cummins makes an even more powerful diesel for military vehicles? The Cummins Advanced Combat Engine (ACE) produces up to 1,000 horsepower. Even more incredibly, it harnesses opposed piston technology to put two pistons in each cylinder. Therefore, it boasts 14.3 liters of displacement, with just four cylinders.