Hi all, for our general info please.... According to this chart from Eartheasy.com, the most fuel-efficient speed for your car is roughly 55 mph, or 90 km/h. Increasing your speed from 55 mph to 75 mph boosts your fuel consumption a stunning 20 percent! You can boost your vehicle's fuel efficiency by as much as 30 percent simply by keeping it well maintained and driving it correctly. Here are a few suggestions: Avoid jackrabbit starts, tailgating, or pumping the gas pedal. Starts and stops increase fuel consumption dramatically. Take advantage of cruise control whenever possible -- driving at a steady speed saves fuel. Try to avoid idling your car for more than a minute. Keep your tires inflated and switch to radial, if you haven't already. Reduce drag by keeping your windows rolled up, removing unused bike racks, and emptying your trunk. Optimal fuel efficiency varies from car to car, so check your manual for more suggestions. The best option, of course, is simply to drive less. You can do this by planning trips ahead of time to avoid peak traffic hours or doing your errands a little closer to home.