Yes, adding ethanol cuts fuel mileage

Dear Bob: A reader recently wrote about experiencing a sudden drop in gas mileage. I can think of a possible nonmechanical explanation.

When alcohol is added to the gasoline in our area, from October through February, my mileage drops by about 25 percent. So I drive to Idaho, which is only about 10 miles away, to get my fill-ups during those months.

I don’t make a special trip for this, as I go over there to church every Sunday.

— L., via e-mail

A: I’m really glad that you brought this up, because the addition of alcohol — usually it’s ethanol — to gasoline during the winter months does indeed affect fuel economy.

While it does reduce tailpipe emissions during this peak time for emissions, as it is intended to do, adding alcohol also reduces fuel economy, usually by about 10 percent. In extreme cases, and you seem to be one, the drop can be as much as 25 percent.

If your state adds ethanol to the fuel in wintertime, expect a drop in fuel economy. For instance, my home state of Arizona adds as much as 10 percent ethanol between Sept. 30 and March 31, and I can see it in my mpg calculations.

Adding insult to injury is that this drop in fuel economy comes in the winter, which — because of cold engines, bad road conditions and the like — is already the toughest time of year to get good mileage.

So it’s a double whammy, once from Mother Nature and once, however noble the motive, from the government.

Dear Bob: My left turn signal works occasionally, but does not work most of the time. My mechanic said that it would have to quit working completely before he could diagnose the problem.

That was six months ago, and it still has not quit completely. What can I do?

— L.R., Spokane Valley, Wash.

A: Well, you could plan your driving so that you make only right turns, but I doubt that it’s the best solution.

If the right signal works — and I assume that it does, since you didn’t mention it — and the left signal works only sporadically, then the turn-signal stalk must not be making proper contact when the left signal is engaged. It could be something as simple as a loose connection at the signal junction, or it could be the unit itself going bad. Or there could be a problem in the wiring, the bulbs or the connections that lead from the turn-signal switch back to the front and rear left-turn-signal lights.

I’d check the wiring, bulbs and connections first. Then, if everything seems in order, you will need to have the signal switch itself taken apart so that it can be looked at.

If you’re lucky, perhaps a bit of soldering or screw-tightening will cure the problem. If not, the whole unit may have to be replaced.

Dear Bob: I recently read in your column about the man who had two episodes with spare tires that had lost their air.

You might have suggested buying an electric air pump that plugs into the cigarette lighter or into a 12-volt-power outlet socket. The pumps are small and easily carried, and can be purchased from an auto-parts store or in the auto sections of various department stores. They cost $20 and up, depending on the quality and pressure needed.

I have learned much by reading your column. Please keep giving advice to us “dummies.”

Thanks,

— P.S., Ephrata, Wash.

A: Thanks for the tip, and for the nice words. But watch out whom you’re calling “dummies” — my readers are a knowledgeable lot, and this “dummy” has learned much from reading their letters.

AMERICAN DRIVERS FIGHT BACK

Here’s a tip that will help you get better gas mileage while fighting terrorism and cutting our nation’s dependence on Mideastern oil:

Clean, fresh oil of the proper viscosity is a must for increased fuel economy and better engine performance.

The higher viscosity, or thickness, of old, dirty, contaminant-laden and past-due-for-a-change motor oil, as well as its depleted additive package, add up to reduced fuel economy and possible early engine failure.

It is essential that both the oil and the filter be clean. Change both at the manufacturer’s prescribed intervals, preferably every 3,000 miles or every three months, whichever comes first — and even more often if weather, driving or road conditions dictate.

If you examine the fine print of every industry-standard fuel-economy road test, you’ll note that each vehicle receives fresh oil immediately before the tests are conducted. That’s because the car makers don’t want old oil to play any part in negatively affecting the fuel-economy results.