For the simulator, I used the PT-40 as well. You can also go into the options and add what engine you are using, and check against other specs of the Avistar. That's what I did, and I found both to fly almost identically. Although, I will say that take off and landing on the simulator has a lot to be desired over real conditions. I also picked the same prop to use. If I remember, you need to take the existing plane, make a copy, and then use the copy for the mods. I haven't done this for a while, so I may be off a little, but I am pretty sure that's what I did. Just called the second plane Trainer 1 or something like that.