I fly a 747-200, 10 tanks option.
In our books, the max fuel is 166,400 kg for full tanks.
It is a limitation.
xxx
Should it be hot weather, we top the tanks, and barely can put 155,000 kg.
In Siberia, in winter, topping the tanks, it is possible to fill 170,000+ kg...
That is
over the weight limitations. Illegal...
xxx
One thing to remember -
Fuel is sold in litres, or gallons... by volume.
If you buy COLD fuel, you get a discount... HOT fuel is... more expensive.
Your jet engines only know weight and mass... not litres.
xxx
So, instruct fuelers to fill the tanks at the time of day fuel is cold.
Stay away from fuel trucks, the sun heats the fuel quickly.
Underground tanks might be better.
But... if you top your tanks with cold fuel, the sun will expand fuel in the tanks.
And your tanks will drip...
xxx
In my little car, I buy cold gasoline... early morning. I do not top the tank.
Happy contrails