Xmas decorations are altering your car’s fuel economy

GMC Terrain Xmas decoration

A (relatively) funny experiment with a strong message

It seems like someone started asking the important questions this holiday season, like “How much are the Christmas decorations are altering your car’s fuel economy?” A wind tunnel was the best way to answer that.

The car choice was the 2018 GMC Terrain, a crossover SUV that boasts an impressive decrease in drag compared to the previous generation. We don’t know the numbers, and GMC is definitely not keen on posting them in the press releases, so we’ll just take their word for it.

From these slo-mo aero cutscenes, we’ve learned that a Christmas tree doubles the Terrain’s drag coefficient. But the real gem of information here is this: the nose-and-antlers decorations bring down the car’s fuel consumption with 1 mpg (about 0.2 l/100 km, if you're European).

While the Chrismas tree is supposed to be on the top of your car for a short distance, those horrible decorations are there to stay, unfortunately. So if you want to make a change for the better, keep off cosmeticizing your car.

Talking about Chrismas tree in/on cars, take a look at BMW's 2018 Christmas ad.