Yep, with the wife aboard the MPGs go way down, because she likes the A/C when it gets hot.
I think the extra passengers are why I am getting 55-56 on the highway with my VX. I think if I was alone i might get 61 or so, but I gotta try it and see.
doesn't do much to my FE but I drive a landcruiser so even when theres the full 8 in the car it doesn't bother the accel all that to much, but when for about have a tank on my old civic we had 9 people in there (don't ask me why or how) and my accel was fing terrible and was dropping into the low 30s mpg-wise.
Staying in shape one pedal or step at a time.... mabye helping out the wallet also
I get much worse with my wife and kid in the car but of course my wife could be driving that 46 miles one way to work and then my kid could be driving the same 46 miles to work in her car too. So I'm putting 100 miles a day on one car versus 300 miles a day on 3 cars. In the end (for me); more pax in the car means worse mileage but $$$ saved.