A Lot Of Weight In Your Car = more gas consumption

[Florentin]

I carry many things back and forth in my sedan (Corolla 08)
I was thinking that I tend to forget many of the items in the trunk, on the back seat, and then I end up carrying them along.

That extra weight has do make a difference on gas consumption.
What do you think?

[PetrNovy]

Exactly, though as masuofani said, unless the weight compares to several passengers, you'll be hardly able to notice.