Ray Magliozzi

Dear Car Talk: I recently purchased a plug-in hybrid. My question: I charge it up overnight and drive about 40 miles a day, all on battery power, as the battery-only range is about 50 miles. So, I can go weeks — if not longer — without using any gasoline. Should I be adding a fuel additive of some sort?

Thanks for your answer. Like so many, I look forward to your weekly articles. — Simon

You and libel lawyers all over the country look forward to my articles every week, Simon.

No. You don’t need a gasoline additive. It’s unnecessary. Modern gasolines are capable of sitting for at least a year, probably longer, without breaking down or causing you any problems.

So, if you go weeks or even months without running your engine, your gasoline will be just fine. I wouldn’t even know what additive to recommend to you these days. Honestly, as good as engines are now, and as clean as top-tier gasoline is, I’d be hesitant to put anything in the gas line. And there’s nothing that’s necessary.

Also, I remember when the Chevy Volt, the first U.S. mass-market plug-in hybrid, came out in late 2010. A concerned owner asked us this very same question.

We put it to an engineer at GM, who told us that the Volt kept track of how often the gasoline engine was used. And if it went unused for a year, the computer would automatically run the gasoline engine to use up the fuel and force you to replace it.

Pretty smart, huh? Modern plug-in hybrids do the same thing. I don’t know exactly what calendar each of them is on, but they all track the use of the gasoline engine, and will run it periodically to keep things moving, including the gasoline supply.

So, unless you really miss your favorite gas station restroom, all you have to do is plug in and drive, Simon.

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