^ Yep, what he said. A two hour race on Blackwood is about 75 laps, but the XFG has the fuel capacity for about 90 laps. A no-stop strategy would be possible if you can make the tyres last - I'd take about 85% fuel for that.
To determine what pit/fuel strategy is best, you have to first assess what a pitstop costs you (how much time you lose compared to a normal lap). Then you have to find out (by lots of testing) how much faster you actually are with a lower fuel load and not having to be as careful with the tyres. Then the question basically looks like "am I faster with 80% fuel and careful driving, or two times 40% fuel + time lost at a pitstop?"
You also have to consider that a pitstop generally breaks the flow / your concentration and is a risk in itself, as you could get a drive-through if you're not careful enough. Additionally to that, if you drive a no-stopper at 98% of race pace to preserve the tyres you'll most likely have less accidents compared to driving at 102% at a one-stopper, where you're always pressured to be as fast as possible to make up for the time lost at the pitstop. As a bonus, usually not trying to drive fast makes you end up with faster laptimes than when actively pushing it
