These Fuel-Economy Myths Are Costing You at the Pump — Here’s What Actually Works

With fuel prices still punishing drivers and new-car prices topping $50,000, every wasted gallon counts. Yet the internet is packed with “tips” that don’t just fail to save fuel—they actively burn more.

Coasting downhill in neutral sounds clever, but modern fuel-injected engines cut fuel delivery entirely when you lift off the throttle in gear; drop into neutral and the engine idles, guzzling gas. Premium fuel in a car that doesn’t require it is another wallet-drainer: higher octane buys nothing in a regular engine, and the EPA says the extra cost usually outweighs any savings.

Warming up a modern engine in the driveway is pure waste—fuel-injected mills warm faster under gentle driving than they do idling. The windows-down vs.

AC debate also flips with speed: at low-town speeds, open windows beat AC; on the highway, open windows create drag that can erase AC’s fuel penalty, so run the compressor instead. Cruise control on flat roads saves fuel by smoothing speed, but on hills it overworks the throttle to hold a set speed, burning more than a driver who naturally eases up climbs and coasts down.

And forget crawling away from every stoplight—lugging the engine in first gear is less efficient than a smooth, timely upshift to the highest practical gear. The real play is simple: stay in gear, drive smoothly, set the cabin temp sensibly, and let the car’s electronics do the work.