GREENSBORO, NC -- Consumer Reports got this question, "I like to keep my gas tank full in case of traffic tie-ups, but is it bad for the engine not to let the old gas get used up first?"
We checked around and Consumer Reports and Cars.com experts both answered the same.
"Actually adding new gas to the old gas is better for the engine," says Patrick Olsen of Cars.com. "The reality is gasoline gains octane not loses it over time, but I think that comes with a misconception about what drivers think about their cars. The real danger is your gas can turn into a varnish or gum if it sits too long."
And what's too long? If you're letting your car sit for 6 months or longer, you need to add a gasoline additive or stabilizer.
(© 2016 WFMY)