We are considering the purchase of an Airstream Classic '92 or '92 trailer. The GVWR would be 10,000 to 10,300 lbs. Assuming that the tow vehicle would be a GMC Yukon a 3/4 ton XL with a Vortec 8100 V8 engine, (a) What can we expect our average miles per gallon to be while towing? (b) While not towing? Ron Lawrence