AFAIR, AI have no 'understanding' of fuel loads or tyre temps. The effect of this is that if you train them up from scratch on a long race, they do well by the end... unfortunately, when you start another session, they crash out all over the place, because they are trying to drive lines and braking points for warm tyres and low fuel weight!
Maybe, if you did multiple training sessions of 2 - 4 laps each, it might work out better? I'm certainly not waste my time doing that though
col