STANFORD UNIVERSITY SCHOOL OF EARTH SCIENCES - EARTH SYSTEMS PROGRAM

Sustainable Choices

Don’t Speed On the Freeway

Simplicity:
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Carbon Impact:
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Money Savings:
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Health Helper:
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Overview
Take it slow on the road. You’ll save gas, stay safer, and maybe even reduce stress. Studies show that fuel economy peaks at about 50-55 miles per hour. Above 60 mph it begins to drop dramatically. To see the graph, look here. If you’re looking for a way to improve fuel efficiency (have your eye on that hybrid car?), try the simple steps that don’t require any investment on your part: stay under the speed limit; don’t drive aggressively, and keep your car properly maintained. www.fueleconomy.gov

Tips & Tricks
Follow the speed limit. Speed limit are there for a reason—usually safety. But they also give good guidelines for fuel efficiency. It is especially unwise to break the speed limit on the freeway, where an increase by 10 mph can cause your fuel efficiency to decrease by 5 mpg.

Plan ahead—leave early. Try not to rush around. Give yourself a break, let yourself relax, and leave yourself an extra ten minutes of buffer time. This way you won’t feel compelled to speed.

Web & Print Resources
Fuel-efficient driving tips:
www.fueleconomy.gov
www.edmunds.com
www.shell.com
www.consumerenergycenter.org

Fun Facts

Peak fuel efficiency is achieved at about 50 or 55 mph.

By driving above 75 mph, your fuel efficiency can drop as much as 10 mpg below 50 mph fuel efficiency (i.e. from 30 mpg to 20 mpg).

Drag is proportional to velocity squared.