Dear Tom and Ray:
Winter is coming, and I have two gallons of oil/gas mixture (40-to-1) for my weed whacker that I don't want to save for next year or try to dispose of. Is it safe to add this mixture to an almost-full tank of gas in my 2004 Honda Accord? I use 87 octane and live in Cleveland. Thanks! — Jeff
Ray: You live in Cleveland? You may want to just hang on to the gas-oil mixture and buy yourself a snow blower, Jeff.
Tom: Actually, it's fine to use it in your car. It's a relatively small amount of oil (1 part oil to 40 parts gasoline).
Ray: It won't harm the engine, the fuel-injection system or the catalytic converter.
Tom: It's not great for the environment, but, presumably, you would have burned it in your weed whacker anyway, so it's doing no more harm being burned by your car.
Ray: Most of my brother's cars burn more oil than that on their own, due to age and/or disrepair. In fact, some of them burn more oil than gas.
Tom: Keep in mind, you also can save the mixture for next year. Gasoline generally is good for at least a year, these days. You can make it last even longer by adding a small amount of gasoline stabilizer, like Sta-Bil.
Ray: And if you keep it, you also can use it in your lawnmower, your chainsaw, your portable generator or your deluxe gas-powered butt-scratcher, Jeff.
Tom: But if you do decide to power your Accord with this mix, I would do it over several tankfuls, rather than dumping the whole thing in at once. That'll minimize the concentration of oil and ensure that no harm is done.
(Car Talk is a nationally syndicated column by automotive experts (and brothers) Tom and Ray Magliozzi. Write to them at the Car Talk website.)