arf, something is strange, I downloaded your car and here I have all tyre compounds in DumbAI as expected:
View attachment 1515274
So I don't know what to do ?!?
For this part, so if I sum up things, you are in race conditions where Mandatory Refuel is selected in DumbAI but in your case, the race conditions (fuel multiplier and race lenght) make that a pit stop for fuel would have been expected whatever Mandatory Refuel selected or not.
I think you're in the mistake I mentionned in my post:
If there was an expected pitstop, then nothing happens for this strategy so it should not change its tyre compounds during race. (I made a mistake and forgot to add Mandatory Refuel strategy in this loop and so only Tyres&Refuel and Mandatory Mixed Compounds with Refuel do adjustement between fuel and tyres compounds currently so I'll correct it for the next update, so thanks again for the report )
So no, in this 1.1, they do not adjust their fuel to make a shorter first stint if they have an alternate compound that is softer, nor do they add a supplementary pit stop. I'll add the fuel adjustment for Mandatory Refuel strategy in the next hot fix.
Also, I think I must precise that the fuel strategy has some "edge" situation that can leads to confusion.
First, keep in mind it is computed with an estimation at start from fuel_cons.ini . But then fuel level is assessed in "real time" during the race. DumbAI takes a 10% margin in this fuel consumption, just to be sure that AI won't run out of fuel. And I suspect there is a first consumption margin in fuel_cons.ini . So it is likely that the expected pit stop strategy will not exactly be the same as what happens during the race as it is almost sure that the car will consume at least 10% less that what was computed, hence they will stop later than expected because the pit stop is triggered only when fuel level is below "fuel quantity needed to perform another lap"
Second, there is a random value in fuel estimation to make some diversity between bots , +/- 5% that will apply to the base 10% so that the bot ends up from a 15% margin up to a 5% margin. In rare cases, when you're near the limit of the fuel tank size, it can lead to different strategies.
Here is an example with your car, on Kunos Monza, 15 laps with fuel consumption rate set at x5.
I obtain this:
Abdullah Al-Mutawaa fuel_strat = 98.1, 98.1, 98.1 = total of 294 L
Cédric Levratti fuel_strat = 135.4, 135.4 = total of 270 L
Robert Kajetanowicz fuel_strat = 96.7, 96.7, 96.7 = total of 291 L
Jacques Villeneuve fuel_strat = 139.5, 139.5 = total of 279 L
Mika Salo fuel_strat = 136.9, 136.9 = total of 274 L
Why two different strategies ? because of the random effect.
86.325 km to race, 1.68 km/L => 0.336 km/L (due to fuel rate) => mean 10% margin of DumbAI = 0.3024 km/L => 285 L
Here the max fuel tank is 140. Estimates are all in the range of 10% of variation in fuel. 285 L is more than two fuel tanks.
So bot will first try to make two stints => 142.5 L per stint => not possible due to tank max size => then three stints => 95 L => OK for tank max size.
Now say that bot estimated with only 5% margin: consumption is now 0.3192 km/L => 270 L
bot first tries to make two stint => 135 L per stint => OK , only one pit stop.
What will happen during race ? Likely everyone will spend less fuel than expected. With 10% of margin, real consumption may be like 280 - 28 => 252 L
For Jacques Villeneuve, likely, he will make a longer first stint than expected and have a shorter second one.
For Abdullah Al-Mutawaa, that means it is possible that at his first pit stop, he will be able to finish with only a fuel tank and then switch to a 1 pitstop strategy (but it is not likely as he will use the same estimate with margin than before).
Now you see why it is not easy to explain what happens in race. Not to mention that it is almost impossible to assess tyre wear before start...
I made these random picks while I did'nt know exactly how fuel was managed by AC. Now with more experience, I wonder if it would not be easier to pick only the fuel_cons.ini value without any margin or random effects and then assess dynamically fuel consumption per lap to correct projection with real data when pit stop occurs. Should be more accurate and easier to debug...