Originally Posted by DrkKnight614
Posted via FF Mobile 3 extra people is plenty to kill the mileage. If you add in hills and other enviorment things where you have to put your foot down a bit more, your mileage will go down. In this day and age, most 3 adults do not weight approx 500 lbs. Try 600. 500lbs would average out to about 165 lbs a person, America is a bunch of fatties. Just saying 500 lbs I could see killing at least 5mpg.
. But he's from Canada, maybe they grow them smaller?
Either way, you are probably close to correct in the mileage lost through additional weight.