It's across all DayZ with the 1.30 update, PC and cosole. Whenever servers reset or you log out and log back in later, fuel and water are at 0%. Following to see if you get an official reply.

Glad I'm not the only one, and I also died of heatstroke even tho I did all the things. Not liking this version so far

In 1.30 the load path restores a vehicle's position, parts and inventory, but does not create a usable fluid state. Reading returns 0 and writing has no effect. The save path itself is fine.
it's a engine related bug , so as a server owner , i can only make a script that work-around it by create a persist number of fluid of cars that when a player get near the car , load the saved amout of fluid (fuel, water,etc)
waiting for the official fix.

https://report.bistudio.com/issues/DZG-1289
there is also a link to a server side workaround from me, but there are more mods in the workshop. didn't test others, mine is a server side mod