Can i bother someone to explain what is the amp rating of my trane xv95 120btu furnace----the plate inside says "15 amps", I am comparing this to an old single speed 80 btu trane xe90 i have---and it says "10 amps". Proportionally that is the same electric motor efficiency. I was lead to believe that the variable speed motor is 70% more efficient--I was expecting the amp rating to be about 5 rather than 15.

Thanks (I"m having a whole house/part house generator installed and was told to gather this for unit sizing).