Enroute fuel burn performance

[MD82]

Hello ini,

I wanted to ask if the Tristar's enroute fuel burn performance has been vetted against real life performance charts. I don't doubt you have. However, I use not only SimBrief but also PFPX extensively. What I am seeing after keeping my navlog completely from start to finish on 9-hour flights is that,

1. The ini Tristar burns ~14% less fuel than the SimBrief profile

2. The ini Tristar burns ~ 9% less fuel than the PFPX profile

Now, I'm not saying which of the three are right and I'm happy to adjust both SimBrief and PFPX accordingly. I've tried to source any cruise tables from the Tristar -500 to verify. Unfortunately, I can't find anything online.