Improving Gas Mileage - Installment 6

We come to the last of the six today, but don't worry, this is not the end (see the bottom of the post).

Improvement #6 – Lighten Your Load

Potential savings: $0 – 78 (0 – 3% improvement)

Cost: a little time

Depending on how much junk you usually carry around in your car with you, the savings here can vary dramatically.

The Department of Energy and EPA advise that, in the average car, an extra 100 pounds can decrease gas mileage by 1-2%.

I personally think that estimate is high, but make sure you aren't carrying around more stuff than you need to. I try to never let the trash in my car get above knee level for just this reason. Just kidding, but I do try and make sure that I am not carrying extra boxes, sports equipment, etc. in my trunk if I don' t need to.

The principal is simple: the less mass you are accelerating and moving around, the less energy it takes. The benefits are more noticeable in smaller cars: the mileage in my old 4-cylinder Ford Escort was significantly lower with two extra people in the car. Those two extra people add about 10% to the car’s weight.

Depending on the vehicle (engine tuning, rolling resistance, etc.), the benefits can also vary. A 10% difference in weight might make a 3% difference in the Escort mileage but only 1% in another car. Dropping 1% of the weight (about 30 lbs) may improve mileage only 0.1-0.2%, which you probably could not even measure.

Nevertheless, carrying less weight around is easy and even a 0.1% savings can add up (about a gallon a year). Just remember not to carry around extra weight if you can avoid it!

As you probably know, it is prudent to carry some emergency supplies around with you – please don't get rid of these!

So much for the improvements. Now for some products to watch out for...

Watch Out for Gimmicks

The September 2004 issue of Consumer Reports® evaluated add-on products that bill themselves as "gas mileage improvers." Unfortunately, none of them live up to their claims. The Fuel Genie, Platinum Gas Saver, and Tornado all cost around $100 but none of them improve gas mileage.

And these aren't the only gimmicks out there...

A friend of mine from church was looking into on-board hydrogen generators where the plans run $40 up to $1000 for the complete "system". After looking at the different options, I remained unconvinced of any scientific benefit (I can give you more analysis if you want, but I don't want to bore anybody...:) ).

Southwest Research Institute (a respected third-party test lab) is actually doing research on one of them right now - so I will let you know if they find anything beneficial!

Most (if not all of these) are just gimmicks like the others that Consumer Reports tested almost 4 years ago.

With many of these products, people looking to save money on gas with these products just spent $100 or more for NOTHING. I can't believe people at those companies sleep very well at night!


Well, that's the end of the six part series, but stay tuned...

Because of the popularity of this series I will be taking a look at other ways to save money on gas that do not involve improving gas mileage in the near future.

Until then, may your gas (or diesel) bills be low!