I am noticing with the SSG 747-8F and Rotate MD11, and other turbo prop airliners (Metro III), the estimated fuel burn is quite a bit higher than the actual burn. I am using XP 11.55, latest version of the models.
I have checked the following per another similar post here:
Please double check the following:
Make sure that both the OFP and Aircraft are using the same units (KG/LBS). - LBS
Make sure that the ZFW in SimBrief matches the ZFW you have set up in the PMDG payload settings. - This does seem different, can this be corrected in Simbrief?
Make sure that you are using real world weather in the sim. - Yes
If you are getting an “Insufficient Fuel” message in the FMC prior to departure, make sure that you have loaded enroute winds, and also make sure you have entered any planned step climbs into the FMC route page. - This does happen occasionally in the SSG but, the MD11, never seen that message and the fuel I have remaining is nearly double what the OFP shows, not even close.
Make sure that you are using the same cost index on both the OFP and in the FMC. - Yes
I don’t know if we can tweak our fuel burn rates in the OFP, but, I need some way to get the fuel closer. I flew from EDDK to KMEM today in the MD11 and I way over on fuel, which means, I carry less load, which is less VA pay : )
SimBrief profiles are based on the real world aircraft, but different simulator renditions can have varying degrees of accuracy. I am not aware of how accurate the SSG 748 and Rotate MD11 are to the real thing.
You can create a custom airframe and tweak the various weights to match those of the add-on you’re flying. Or, you can set up your payload in the sim, take note of the resulting ZFW, and then enter that ZFW directly under the “ZFW” option (under “Optional Entries”) when creating your SimBrief flight.
To tune the fuel burn, you can use the “Fuel Factor” option (available both in the custom airframe options and directly on the flight options page in the “Advanced Aircraft Options” section). For example, to tell SimBrief that the aircraft should burn 10% less fuel, use a Fuel Factor of “M10” (i.e. -10%).
Went the custom frame route since, the ZFW, etc should work out if the initial weights are correct in Simbrief. There were some significant differences in the Rotate MD11 and the default Simbrief MD11. Got the weights from the manual, plugged them in and performed a test flight from KMEM to KDFW and it was pretty spot on, much better. Just need to fix each model, it even helped with the large FL discrepancy between Simbrief and the recommended FL in the FMC, appreciate the heads up. I have looked at the custom frames before but, never really took the time to use it.