Christmas decorations are the best. The glimmer and colors of the lights and decorations almost make up for how miserable it is to leave and get home from work in the dark on these cold winter days. However, some people take Christmas decorations too far. No, we’re not talking about your neighbor Frank who keeps the whole neighborhood up with his Times Square-grade light display set to the Trans-Siberian Orchestra’s greatest hits on repeat. Instead, it’s the people who move the decorating to their cars.
No one thinks your SUV is Rudolph, wreaths don’t belong on grilles, and blinking colored lights are not exactly legal to display on your roof rack for what should be obvious reasons. But, if good taste isn’t enough reason for these people to rethink their decorations, now there’s science to back it up.
Back in December 2017, General Motors did some wind tunnel testing with a 2018 GMC Terrain and found that, other than the wreath, which doesn’t change the aero enough to make a difference, you are looking at a minimum of a one MPG penalty to remind people that it’s Christmas, as though they could forget. The wreath can, however, block air from going to the radiator and potentially cause overheating problems. Why risk it?
Another downfall to the reindeer antlers, in particular, is if someone who is not used to driving the car borrows it for, say, a fast food run, and then accidentally rolls down the wrong window when they go to pay, they could make it all the way home before realizing they have to go back to find the stupid antler they dropped. Don’t ask us how we know that.
Here’s a breakdown of what else GM found during the test.
Per USA Today:
•Antlers. Reindeer antlers and Rudolph’s nose create about a 1-mile-per-gallon decrease in highway fuel efficiency and a 3% increase in drag coefficient — commonly understood as air resistance.
•Bow. A roof-mounted bow creates a 3.5-mpg decrease in highway fuel efficiency and a 15% increase in drag coefficient.
•Christmas tree. A tree tied to a roof creates a 30% decrease in highway fuel efficiency and a 70% increase in drag coefficient. Air pushes against a tree with about 90 pounds of force.
•Wreath. A grille-mounted wreath has no impact on aerodynamics but may reduce cooling airflow to the engine.Advertisement