I just filled up and put 18.36 gallons in my 528. Checking the manual it indicates fuel capacity as approx 18.5 gallons and the reserve 2 gallons. Does this mean total capacity is 20.5 gallons or should this be read as meaning the 18.5 includes the 2 gallon reserve? Does the low fuel indicator light come on when you are down to 2 gallons? After all these years you would think I would have asked myself this a long time ago.