star wars - How was the Resistance able to run out of fuel?

In Star Wars: The Last Jedi

It's a major plot point that the Resistance must find some way to escape the First Order before their ships run out of fuel.

In space, there is very little resistance to motion, so once something starts moving, it tends to stay moving. This is why real life spacecraft barely need to burn fuel once in orbit of something. When

the rebel ships are being chased by the First Order, they appear to stay the same distance from the ships after initially moving out of effective range.

The only way this makes sense with both distance and fuel burning is if they are accelerating at the same rate. At some point I believe someone says the Resistance ships are faster (I am assuming this refers to acceleration, because neither fleet should have a terminal velocity other than the speed of light), so I suppose they were only accelerating as fast as the First Order to save fuel, and had determined they were not sufficiently fast to totally outrun the First Order.

However, I find it hard to believe that two fleets could accelerate, near the maximum capacity of one of them, for at least 18 hours and not go into hyperspace. These are ships that can traverse systems in minutes if they choose, and I find it equally hard to believe that the First Order would only use a fraction of their available power in pursuing the rebels. How then were the rebels able to run out of fuel without changing their velocity significantly?

Answer

The captain of The Finalizer (General Hux's flagship) says:

They're faster and lighter, sir. They can't lose us, but they can keep out of range where our cannons are ineffective against their shields.

I think the important part is "They can't lose us", which implies that "faster" doesn't mean the Resistance fleet doesn't actually have a higher top speed. Instead, it probably means that they're able to maneuver faster. So if the First Order started gaining too much, they could turn sharply and re-establish the distance before The Finalizer could react.

These maneuvers that keep them out of range would consume fuel - in addition to the fuel needed to power the shields.

(I realize this isn't exactly supported visually in the movie - it definitely looks like they're travelling in a straight line the whole time. But if they are, it seems like the First Order would have caught up to them - or at least they'd be able to send a ship ahead of the Resistance Fleet and ambush them. The only way they wouldn't be able to do that is if the Resistance Fleet was not actually moving in a straight line.)