U.S. Drivers Adopt Hypermiling Tactics as Iran War Pushes Gasoline Above $4

Q: Does leaving that empty roof rack on your car silently drain your wallet every time you hit the highway?

Yes. Leaving an unused roof rack on your car can quietly raise fuel costs, especially on the highway. The reason is aerodynamic drag. At higher speeds, a car uses a large share of its power just pushing air aside, and roof racks disturb that airflow. Consumer Reports advises removing roof racks when they are not in use for that reason. The fuel penalty grows sharply with speed, so the effect is much smaller in city traffic and more noticeable at 65 to 75 mph. How much it costs depends on the setup. Broad estimates in the automotive guidance cited here suggest roof-rack accessories can cut fuel economy by about 2% to 25%, with the biggest losses coming from loaded cargo boxes, kayaks, or surfboards. An empty rack is usually on the low end, but some estimates put empty crossbars at roughly 1 to 3 mpg lost at highway speeds. A large cargo box can cost far more, often around 3 to 8 mpg. That fits the broader hypermiling message in the news story: drivers often have more control over fuel spending than they think. Smooth acceleration, gentle braking, proper tire pressure, and lower highway speeds usually deliver the biggest gains, but removing unnecessary roof gear is one of the easier fixes. If you rarely use the rack, taking it off between trips can save money over time. If you need roof storage often, a lower-profile, more aerodynamic setup will usually waste less fuel than a taller or boxier one.

1 articles · Updated · The New York Times · Sep 7

Hypermiling is gaining traction among U.S. drivers as summer gasoline prices surge, with motorists stretching each gallon by accelerating gently, coasting toward stops and avoiding speeding.
Those tactics target fuel efficiency directly: hypermilers say smooth driving can cut fuel use when pump prices leave households feeling squeezed by the Iran war.
Some drivers go further by limiting air-conditioning use or stripping vehicle weight, though the core approach remains reducing hard starts and stops.
The trend shows how consumers are adjusting behavior rather than waiting for relief, turning everyday driving habits into a hedge against war-driven energy costs.