Correct!

So I have never used engine Techs but if I were to use it this is how I do it

1. I am at speed 2 and want to go to speed 3 then use Engine Techs I have a Nav Command or Nav Token I spent it to increase my speed, move and then use Engine Techs as I have already spent the command or token?

2. I am at speed 3 I have a Nav token. I move at speed 3 not spending my Nav Token I want to use Engine Techs but can not Because I did not spend my Nav Token before I moved?

3. I am at speed 2 and I have a Nav Command I don want to change my speed, I have a Nav Token, So I spend the Nav Command move speed 2 see where I am then I have a choice to use Engine Techs if I want?

4. If I spend the Nav command change my speed but not my Yaw can I change the Yaw when I use Engine Techs?

1. Correct

2. Correct

3. Correct

4. No. The extra yaw only applies to the maneuver that you spent your command for. After that maneuver resolves completely, then you may resolve the Engine Techs maneuver, but the yaw, or speed change wouldn't carry over.

thanks a friend of mine has been Engine Techs a lot and now I know why I lost our last game