I would probably look for something else that’s undervalued to invest in now.

I invested in PowerShares DB Oil Fund (Ticker DBO: http://www.google.com/finance?client=ob&q=NYSE:DBO). At the time that I wrote this article, it was trading near it’s all-time high of around $50. That makes sense because I wrote the article in response to high gas prices. If you waited until late March of 2009 (when the gas prices went back down), you could have gotten in at around $20. It has been trading between $31-32 recently.

It doesn’t track gas prices perfectly because there are a lot of other factors that play into the final gas price, but it can be used as a partial hedge, which along with the other tips mentioned can help with the high cost of gas.

The other major thing we can do to conserve gas made from oil is support alternative solutions. Seek out synthetic lubricants, and products made of substitutes. Don’t buy photographic film. Go digital.

My experience seems to be in line with this – about 1 MPG worse with a 90/10 blend that straight gas (I can get 31 mpg from the Taurus on gasoline and 30 mpg from 90/10 on long, straight stretches), although I’ve heard some anecdotes about people getting horrible mileage with a 90/10 blend, for whatever reason.

In my state (Iowa) the subsidy on ethanol drops the price anywhere from 3-5% less than the straight gasoline (it seems to always be 10 cents lower, regardless of the price of gas), so from a cost perspective, it’s a wash.

I have found that it’s worth it to seek out 100% gas over 10% ethanol blend to get about 10% better gas milage.

Big gains are made by:
Reducing RPM for any given speed (reduces number of power pulses from your engine per mile).
Reducing the weight of the vehicle.
Reduce the rate of acceleration.
Reduce your throttle movements. Sharp throttle movements require that the EFI system injects a LOT more fuel compared to slow and progressive throttle movement.

Overrall, drive as smoothly as possible, don’t rev your engine higher than you need to, to drive off from standing start, and don’t move the accelerator pedal up and down as you are driving. Move the throttle pedal very slowly both when opening the throttle, and closing the throttle.

I’ve linked to your article at http://www.colourfulmoney.com.

In that class we were asked to take a before and after measurement of a car’s intake manifold vacuum when we replaced the air filter and cleaned the intake. The car I was working on had a manifold vacuum of 14 inches of mercury (“Hg), which according to the data provided by the manufacturer was about 6-7″Hg below performance specs. I opened the air box and found the filter clogged with blow-by and dirt. After replacing it and cleaning the bottom of the air box, I took another reading, and the gauge held steady at 19″Hg.

A 5″Hg difference is incredible, and the only factor changed was the air filter. Surely if the air filter was NOT the factor there would have been no appreciable difference in the results of my test.

While Consumer Reports states that cars have sensors that will adjust for a clogged air filter, the fuel injection computer can only adjust so far before the parameters swing beyond the spec of the programming, and the ECU either turns on the check engine light, goes into limp home mode, or both, and the performance of the car is drastically affected. The effect of a clogged air filter over time, therefore, cannot be “negligible” as the article states. They also forgot to allow for non-electronic cars that are incapable of making such adjustments.

I also agree with a previous commenter: surely if it were not important, the manufacturer would not recommend that certain routine maintenance (like air filters) be done, as they have no interest in providing what amounts to hundreds of thousands of dollars of unnecessary free parts to customers under the car’s original warranty.

Hmm.