PF question- Explain the HP line of the Tank (modern firearms)

[Fiery Diamond]

So I'm writing a story for fun that involves a world functioning off of D&D rules (primarily Pathfinder, with some 3.5 and house rules for good measure) coming into contact with modern Earth. When the physics of one world clashes with the physics of the other, the D&D mechanics always trump reality, so when determining how real-world weapons affect/are affected by creatures from the D&D world, I try to base things off the Pathfinder modern firearms rules.

At some point I'm going to pit monsters and powerful characters with classes against tanks and planes, so I was looking to see what they have on that. They don't have planes on d20pfsrd.com, but they do have a tank, and I was trying to figure out the HP line. It says "hp 1,920 (959)." I have no clue what that means. What does it mean?

Related: how would you approximate, say, a fighter jet? I say approximate because I don't need a perfectly statted out thing; this is for a story, not a game. Just a general idea of how much damage it would do and could take.

[Darvin]

Vehicles in Pathfinder gain the broken condition when reduced below half hit points. The amount in parenthesis is the threshold at which it gains the broken condition.

[Fiery Diamond]

Vehicles in Pathfinder gain the broken condition when reduced below half hit points. The amount in parenthesis is the threshold at which it gains the broken condition.

Thank you! I would never have figured that out.

[TotallyNotEvil]

Mind, that is not a normal tank.

An M1 Abrams is 26 X 12 X 8 ft (long X wide X tall). It has a volume of 2496 cubic feet.

This behemoth is 60 X 40 X 25 (!) ft. It has a volume of sixty thousand cubic feet. That's twenty four times the volume.

Under PF rules, an Abrams would have, assuming it's 5 squares long by 2 squares wide, an even 200 HP. So it's be 200 (100).

And an M1 is a big ass tank. And a high level martial is going to chop it down in a round, given its base AC of 8 and Hardness 10.