Improving Fuel Economy


Are there any products on the market that do help to improve fuel economy?


No. The only reason your car wouldn’t get the gas mileage it is supposed to is if there is something wrong with it. But no snake oil or nifty looking widget is going to improve your gas mileage in a meaningful way. There are many posts that cover this topic here already.


this is being covered in another post by kerryk at


Smaller more economical car or driving your existing car like a little old lady (not from Passadina.


Here’s a gadget that might just live up to it’s claims.


A lot of ways to increase gas mileage have been incorporated into the cars we drive today. There aren’t many ways left. I like keeping enough air in the tires and keeping the front end aligned. You can get a nicer ride from a pickup truck by getting a bed cover and having some weight in the back, but gas mileage is a lot harder to obtain.


Yea, there are two. #1 is the owner’s manual. Read it cover to cover and follow all the maintenance instructions including the choice of fuel. #2 Drive like a little old lady (not the one from Pasadena) and avoiding idling while parked. Other than that, buy a smaller more fuel efficient car.

Ignore anything you see suggested that you have to buy. It is a SCAM.


If you are not satisfied with the gas mileage that you are getting from your current vehicle, the only choices are:

*Buy a new, more fuel-efficient vehicle
*Make sure that your current vehicle is properly maintained and that the tires are correctly inflated (a couple of extra pounds of pressure is actually better for fuel economy, however)
*Adjust your driving habits/driving style

For information on all three items above, I would suggest that you visit the website of the EPA, as they cover all of the above in good detail.

For specifics on the maintenance on your own vehicle, the ultimate authority is sitting in your glove compartment. Take out the manufacturer’s Maintenance Schedule (contained either in the Owner’s Manual or in a separate, appropriately named booklet) and be sure that your maintenance is up to date.

As to after-market devices, you can forget about them, as they are all scams.


Don’t overlook the most obvious tip of them all. Remember the WWII slogan “Is this trip really necessary?”.


Edmunds did a bunch of road tests on improving economy. see

Basically, moderate aggressive driving was the biggest saver, as most of the replies said. Idling, lower speeds, use of cruise control were the other pluses.

Tire pressure, AC, had minimum effect.


A lot of the people on the hypermiler forums swear by this gadget.

It plugs into your car’s OBDII port and gives you instantaneous readouts of a bunch of engine parameters including gallons per hour, instantaneous mpg, average trip mpg etc. With this thing, you don’t have to wait for the next fill-up to see if your driving technique changes are helping or hurting.
It also does readouts of trouble codes.

It doesn’t make your engine any more efficient but it helps you optimize its efficiency.


Test #1 Aggressive Driving vs. Moderate Driving

Result: Major savings potential

The Cold Hard Facts: Up to 37 percent savings, average savings of 31 percent

Recommendation: Stop driving like a maniac.



20/20 or some such magazine show actually did this test. Took two drivers with the same commute and the same car. After a month the Moderate driver had a gas savings OVER 30 better then the agressive driver.


Tire pressure guage and an owner who regularly checks them.

Also picking tires that have a low rolling resistance helps (very hard to get rating on this, Consumer Reports does this).


When gas started rising a couple of years ago, I adjusted my driving technique as a test. I picked up 1 to 1.5 mpg on my F250 diesel depending on religious I stuck to the changes.

  1. Ease away from the stop light/stop sign. Don’t jump on the gas pedal.
  2. Smooth and easy acceleration onto the freeway, don’t floor it.
  3. Back off the gas pedal when going downhill. If hill steep enough, completely let off the pedal. It’s easy to subconsciously keep your foot on the pedal on hills.
  4. Pre-plan your driving route if making multiple stops. That can minimize excessive driving and maximize fuel savings.
  5. Keep speed down. I’m not saying do 45 in a 65, but you eat up much more fuel for every mph over the speed limit you go due to increased wind resistance, higher engine RPM, etc. So if it’s a 60 mph zone, stick to 60 to 65. Don’t go 75. Over a 10 mile drive, the time difference between 65 mph and 75 mph is less than 2 minutes (1 minute, 40 seconds). To save on fuel, an extra 1 minute and 40 seconds is worth it.


It must be murder passing a semi, however!


Heh heh. The early VWs had the similar effect when the accelerator was pushed down, only they left out the block of wood.