On a recent tour of Volvo’s New River Valley truck plant in Dublin, Va., I had the chance to listen to truck expert Frank Bio discuss aerodynamics and fuel efficiency. He gave a 10-minute overview on the subject in front of a Volvo VN. Here are four quick tips (all of them easy and inexpensive to implement) that I thought were worth sharing:
Slow down: When travelling down the highway at 65 mph, 30-50% of the energy generated by the engine goes towards simply moving the vehicle through the air, Bio noted. A lot of customers are beginning to slow down to improve fuel mileage. Bio said many customers that used to gear to run 72 mph are now reducing their road speed down to 67 mph, which causes a 3-5% fuel economy improvement. There’s just one caveat, Bio says, you must also keep your rear axle ratio set where it will allow the engine to continue running in the sweet spot.
Remove the bug screen: Bio mused that Volvo has spent millions of dollars in engineering to find and remove slight percentages of drag, only to have a customer slap a bug screen on the hood. A bug screen hinders fuel economy by 1-2%, he pointed out. At the very least, he suggested, remove the bug screen in the wintertime when bugs are a non-issue. If nothing else, that should nullify the fuel economy degradation that winter brings.
Spec’ full-length fairings: A full-length fairing on the tractor, which extends from wheel to wheel, can improve fuel economy by 1-3% on its own, Bio noted. You can choose between short, medium and full-length fairings – but the fuel savings really come from the full-length cab fairings.
Minimize trailer gap: Reducing the gap between tractor and trailer from 60 inches to 40 can result in fuel savings of 3%. Moving from 50 inches to 40 inches saves about 1.2%. For those who can’t optimize the trailer gap, Volvo now offers an inexpensive trim tab that mounts to the back of the cab and can be adjusted to optimize air flow over top the trailer.