GMC Tests How the Holidays Can Impact Drag on the New Terrain

Turns out dressing up your car like Rudolph isn’t great for your fuel economy.

byEric Brandt|
GMC Tests How the Holidays Can Impact Drag on the New Terrain

Another holiday season, another slew of festive trimmings being tacked onto cars, trucks, SUVs, and minivans across the country. From wreaths to antlers, some motorists just can’t resist displaying their cheer on their vehicles.

GMC noticed this seasonal phenomenon and was curious about what festive automotive decor does to the aerodynamics of your vehicle. It took the all-new GMC Terrain which has been redesigned with aerodynamics in mind and brought it to a Lockheed Martin wind tunnel in Georgia with holiday trimmings to see how they impacted drag and fuel economy.

GMC tested the aerodynamics of a new Terrain Denali with a wreath on the grille, a Rudolph nose on the grille, reindeer antlers in the windows, a big bow on the roof, and a Christmas tree on the roof and the resulting data isn’t very surprising. Rudolph cosplay with the nose and the antlers will cost you about 1 mpg in your highway fuel economy. A simple wreath on the grille won’t impact your fuel economy at all. The bow knocked down efficiency by 3 mpg while a Christmas tree has the biggest impact by almost doubling your drag. The video below doesn’t specify exactly how much mpg you lose with the Christmas tree, but at least that’s only a one-time trip.

So if you’re feeling festive and you simply must spread your cheer to everyone you share the road with, a tasteful wreath on your grille is the way to go. Just make sure that if it’s illuminated you only use white lights. Law enforcement doesn’t like colored lights on the front of your car. In the words of GMC engineer Joel Ruschman, “if you’re feeling festive this holiday season, decorate your house. Don’t decorate your car.”