Those cute reindeer antlers you put on your car windows during the holiday season? Yeah, well you might put them on your naughty list after seeing your next gas bill.
The aerodynamic drag caused by the antlers apparently have a negative effect on gas mileage, according to a report by USA Today.
According to the report, a General Motors test found the antlers created a 1-mile-per-gallon decrease in highway fuel efficiency.
Having a Rudolph nose on your vehicle also adds to the drag.
Also, make sure you buy a Christmas tree from a nearby lot as a tree tied to the roof of a vehicle creates a 30% decrease in fuel efficiency.