Tag Archive 'ecodrivings'

Jul 11 2008

A New Spin on Old Fuel Economy Advice

This is taken from a thread on gassavers that can be found here. I’ve edited it to my liking, but feel free to check out the original as well. Red will be my/original edits and dark green will be examples and links to further reading on the subject. Feel free to email me with any suggestions or additions.

Original documents can be found at these two sites:

  1. http://fueleconomy.gov/feg/driveHabits.shtml
  2. http://fueleconomy.gov/feg/maintain.shtml

Normal people in normal cars can achieve gains in fuel economy. This is not rocket science or some miraculous product. It is a change in thinking that requires a change in behavior behind the wheel. With many cars today coming with a mpg gauge (see attached list) you can see how these changes are working in real time. For all cars after 1996 a scangauge can be used for getting an accurate reading. Best of all these solutions are free or part of normal maintenance. There are websites popping up with hundreds of members providing ideas and feedback as well in forums. Tracking your mpg is the fastest start to having it improve. Mileage logs are available online at http://www.ecomodder.com.

Drive Sensibly
Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33% at highway speeds and by 5% around town. Sensible driving is also safer for you and others, so you may save more than gas money.

Hypermiler’s: Take driving sensible to the next level, some techniques used are driving without using brakes, coasting in neutral, avoiding jack rabbit starts or using quick starts to get to cruising speed and always traveling in the slow lane.

Check out this page for a general summary of commmon hypermiler driving techniques.

Fuel Economy Benefit: 5-33%
Equivalent Gasoline Savings: $0.15-$0.96/gallon

Observe the Speed Limit
While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.
As a rule of thumb, you can assume that each 5 mph you drive over 60 mph is like paying an additional $0.20 per gallon for gas.

Observing the speed limit is also safer.

Hypermiler’s: Are usually the slowest cars on the road doing the speed limit. Generally known for trying to limit maximum speed to 50 or 55 MPH, hypermilers often drive below the speed limit, especially during a coast.

Fuel Economy Benefit: 7-23%Equivalent Gasoline Savings: $0.20-$0.67/gallon

Remove Excess Weight
Avoid keeping unnecessary items in your vehicle, especially heavy ones. An extra 100 pounds in your vehicle could reduce your MPG by up to 2%. The reduction is based on the percentage of extra weight relative to the vehicle’s weight and affects smaller vehicles more than larger ones. Golf clubs, business materials are just some of the items that add up quickly.

Hypermiler’s: May elect to remove spare tire (instead carrying fix a flat, plug kit), jack, some of the extra seating, as well as changing body panels, such as hoods to a lighter materials.

Fuel Economy Benefit: 1-2%/100 lbsEquivalent Gasoline Savings: $0.03-$0.06/gallon

Avoid Excessive Idling
Idling gets 0 miles per gallon. Cars with larger engines typically waste more gas at idle than do cars with smaller engines.

Hypermiler’s: Turn off the engine any chance they get, especially during coasting. DO NOT idle your car to warm it up, consider purchasing a block heater.

Use Cruise Control
Using cruise control on the highway helps you maintain a constant speed and, in most cases, will save gas.

Hypermiler’s: Use a combination of cruise control and pulse and glide to achieve constant speeds. In hilly areas cruise control is often blamed for using excess fuel.

Check out this page for some ideas on how to deal with hills and flats besides the stedy cruise.

Use Overdrive Gears
When you use overdrive gearing, your car’s engine speed goes down. This saves gas and reduces engine wear.

Keep Your Engine Properly Tuned
Fixing a car that is noticeably out of tune or has failed an emissions test can improve its gas mileage by an average of 4 percent, though results vary based on the kind of repair and how well it is done.

Fixing a serious maintenance problem, such as a faulty oxygen sensor, can improve your mileage by as much as 40 percent.

Hypermiler’s: May use different ECU’s or other modifications to air flow, timing or other systems for their particular vehicles.

Fuel Economy Benefit: 4%
Equivalent Gasoline Savings: $0.12/gallon

Check & Replace Air Filters Regularly
Replacing a clogged air filter can improve your car’s gas mileage by as much as 10 percent. Your car’s air filter keeps impurities from damaging the inside of your engine. Not only will replacing a dirty air filter save gas, it will protect your engine.

Hypermiler’s: Sometimes make changes to the air intakes which induce warm air into the system, this causes the car’s computer to run a leaner mixture. The opposite effect of a cold air intake. For many this works and for many others it does not. Individual testing with instantaneous feedback is necessary.

Fuel Economy Benefit: up to 10%
Equivalent Gasoline Savings: up to $0.29/gallon

Keep Tires Properly Inflated
You can improve your gas mileage by around 3.3% by keeping your tires inflated to the proper pressure. Under-inflated tires can lower gas mileage by 0.4 percent for every 1 psi drop in pressure of all four tires. Properly inflated tires are safer and last longer. Regularly scheduled tire rotations can be beneficial as well.

Hypermiler’s: Set their tire pressures to what the sidewall pressure is on the tire, in some cases above that.

Fuel Economy Benefit: up to 3%
Equivalent Gasoline Savings: up to $0.09/gallon

Use the Recommended Grade of Motor Oil
You can improve your gas mileage by 1-2 percent by using the manufacturer’s recommended grade of motor oil. For example, using 10W-30 motor oil in an engine designed to use 5W-30 can lower your gas mileage by 1-2 percent. Using 5W-30 in an engine designed for 5W-20 can lower your gas mileage by 1-1.5 percent. Also, look for motor oil that says “Energy Conserving” on the API performance symbol to be sure it contains friction-reducing additives.

Hypermiler’s: Use of high quality 0W20 is common, though not always practiced. I won’t say uch else because I’m not an oil expert, but I think you should be wary of oil additives promising big fuel economy benefits.

Fuel Economy Benefit: 1-2%
Equivalent Gasoline Savings: $0.03-$0.06/gallon

Note: Cost savings are based on an assumed fuel price of $2.91/gallon.
Estimates for fuel savings from sensible driving are based on studies and literature reviews performed by Energy and Environmental Analysis, Inc., Washington, DC. Estimates for the effect of speed on MPG are based on a study by West, B.H., R.N. McGill, J.W. Hodgson, S.S. Sluder, and D.E. Smith, Development and Verification of Light-Duty Modal Emissions and Fuel Consumption Values for Traffic Models, Oak Ridge National Laboratory, Oak Ridge, Tennessee, March 1999.
Contact me with questions or comments!

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