With the windows closed on the highway, the vehicle's aerodynamics are improved as there is less drag on the vehicle, according to Frank Hampshire, AASA director of market research.He
noted that studies by Volvo and other automakers have shown that a cooler, drier and quieter cabin can reduce fatigue on longer trips and help a driver stay alert and relaxed for a longer period of time.
"In city driving, you will see a slight fuel economy advantage by opening your windows, but the use of air conditioning at higher speeds can produce a fuel savings," Hampshire
said."There are other ways to improve your fuel efficiency with the top advice clearly being to have your vehicle serviced regularly and driving wisely."
Some consumers with malfunctioning car air conditioners may opt to roll the windows down rather than make repairs, but that's a false economy, Hampshire
noted."The fuel efficiency savings may not be enough to pay for the repair of a non-functioning air conditioner.However, for motorists with malfunctioning systems who have decided to endure the heat, fuel savings make air conditioner system repair worth considering," he