A realistic Huey UH1-H (source DCS flight manual, so if not totally accurate, it is pretty close) has an internal fuel tank of 770 liters, and it's calculated fuel consumption rate is 318 liters/hour. That means flight time of around 2 h 30 minutes, so 10 min flight should have used about 6 % of fuel.

And the ground vehicles. When driving around I've noticed a difference in fuel consumption whether driver uses full throttle or not (with keyboard controls the difference with just W-key and shift+W -key). It's like the difference between a Sunday drive to the store and driving in a race and results in a drastic difference in fuel consumption. The same really should be true when driving on level ground vs. going uphill.

I do agree that the fuel consumption rates are off (the biggest oddity I can remember at the moment relates to the BTR when it's in the water), but a little more detailed study of the issue is probably needed.

Fuel consumption is too high. This is probably by design to make refueling matter, but its annoying. Helicopter fuel consumption depends on many factors like elevation, payload and manuevering. Helicopters should be consuming more fuel with the type of flying ppl do in the game.