I have a Ford F-150 P/U that is only driven when we need a truck for something. It has dual tanks and I usually fill them both, empty them both, and fill both again. Probably only fill them up about five times a year. I recently read that gasoline goes stale over time. Does anyone know the life of fresh gas? Should I add a stabilizer to the gas like I do with yard equipment? Also would appreciate thoughts on oil changes for a vehicle that is driven lightly as this one is. Thank. Dave.

It's not an exact science, but for only filling 5 times a year I would definitely use a stabilizer.

"StaBil" is the one I use for the mower, snow-blower, etc, but for your application, check at an Auto Parts place for what they recommend.

Hi, Dave,
Here is a link:

http://www.alpharubicon.com/altenergy/gaslifepal.htm

It discusses stale gasoline, it's color, with pictures. Good article.
If gas is to sit for a long period, it does sound like adding a good stabilizer will help. Gas does "break up", leaving residue, after awhile, as seen in the pictures of the above link.
I know for outboard motors (for boats), it is recommended that old gas be discarded every winter. Not using it again saves clogged fuel lines, and keeps carbon deposits from building up in the engine.
I would also add a good "drying agent" to dry out any water in the gas in your truck. Water can be added, especially in the winter, by condensation, caused by warm and colder temperatures. Some have even used plain old rubbing alcohol, adding a quart to a tankful. It disolves the water, allowing it to go on through the engine, without harm.
Also, a full tank will gather water from condensation faster than a half full tank.

Most rubbing alcohol is 75% water. Adding alcohol is a good idea, but I would stick to a pure alcohol product commonly sold for the purpose.

I hang out at a forum that endless debates questions like how often to change oil. If as long as you drive it enough to get the engine warm, and have a chance to boil off water and fuel in it, once or twice a year may be good enough. Even with oil heading for $2 a quart, it isn't that much.

Thank you rickj, fredg (great link) and labman for your responses.I think I'll try some dry gas and stabilizer over the winter and see what happens. Rough winters in New England and a two wheel drive pickup truck don't match up well, so she'll sit until needed. (8 cylinder engines and gas stations don't match up well either these days) Thanks again. Dave.

Smart. Just call the $5 (US) bottle of what the parts store guy recommends cheap insurance.

More on gas... there are ways to tell, specifically smell, when it spoils it does smell rancid and turns a dark rich color, now lets say if you have 5 gallons of rancid gas, in a fairly full gas tank, it won't cause harm to put it in. gas starts going bad after a month, fuel stabilizer will keep it from spoiling for maybe a year or so. Now rancid gas will turn to a gummy substance, clogging any orifice it can. Fuel filter, lines, etc. after a while longer it'll turn to the dry powder once called gas. As for oil... changing it say every 6 months with some good cheap oil ( say havoline or what's on sale) will ensure everything will be fine if the engine is driven for a few miles at least a couple times to like labman said, burn off water and fuel. Though for rubbing alcohol, most may be 75% water, but you can easily find 75% alcohol. Though fuel drier will do good. If you're a fan of marvel mystery oil like I am, that will retard the gas from spoiling. Though if you do get a rancid fuel condition, fuel injectors are sure better then having a carb... carb will equal clog city. Oh and also use "sta-bil" it's a well known and pretty good product. And to go further into 2 cycle oil... some will have stabilizer in them, should state or not, but its always good to drain them, run them out, and throw the gas in the cars gastank, either good or bad gas, a relatively full tank in the car, it won't hurt a thing.