Hey Ole Mechanic;Bad Gas

How come gasoline goes bad so fast now-a-days?  My folk’s car sat for just over a year, and us boys had a fit getting it started.  When we finally did get it started, it ran like crap until we put a bunch of fresh gas in it--then it seemed to run OK.  How can we prevent this problem in the future?

South Side of Town

South Side, you have opened a BIG can of worms.  I don't like to get into politics, but your first question only has a political answer. I'm not sure that there is an answer to your second question, but I will try.  By the way, two questions will cost you double.

Today’s gasoline can actually go bad in less than four months, and it is because of smog, ozone, and pollution.  Back in 1988, Congress came up with, and the President signed into law, the Clean-Air Act of 1990--which went into effect in 1995.  I think you can see that they delayed the actual enforcement of the law until we forgot who was in Congress in 1988.  It also gave the auto-makers and the oil-companies time to figure out how to meet the law.

To get clean-air gasoline, a lot of the solvents and lubricating and stabilizing stuff that occurs naturally in crude oil had to be removed from gasoline by refining it out at the refineries.  Also, some light and clean burning stuff had to be added in.  Stuf like butane, alcohol, and MBTE were forced into the gasoline.  Some of this stuff--like grain alcohol--works OK up to a point.  Some stuff like wood alcohol and MBTE not only didn’t work well, it caused some big problems and was discontinued until the problems could be solved.  When the solvents and lubricants were refined out of the gasoline, this did not remove the gums and varnishes from the gasoline.  When gasoline gets hot (you know, like winter in Harper, Texas) the light stuff evaporates, leaving the gums and varnishes to that really muck things up.  This is what happened to your folks car.  The fuel system had a lot of parts gummed and stuck up.  When you added fresh fuel, the lighter solvents were able to un-stick, dissolve and flush things out--we hope!  I would suggest that you put some fuel-additive solvents (cleaner) in with the fresh fuel.  It is your choice here as to which cleaner to use--auto-supply stores have shelves full!  After the car has been driven far enough to use most of the fuel, change the fuel filter.  It sounds like the car may have been parked during the winter.  Gasoline is made both for a specific region of the USA and for a specific time of year.  If winter-gas was in the car and it sat through summer heat, then the gas that was made to evaporate easily for good cold-weather-starts probably evaporated during the summer, leaving just the bad stuff. 

That has been an over-simplified look at why today’s gas is the way it is.  Believe me, you could get an advanced college degree in petro-chemical engineering and still not know exactly what is going on with gasoline.  It will probably continue that way as long as politicians--usually lawyers--pass laws that apply to something that they know nothing about--like gasoline, cars and trucks.  Oh yeah, diesel fuel has not beensafe from legal meddling either, because there are both highway-diesel and Ag/off-road diesel fuels out there right now. Sulfur--a lubricant and pollutant--is pulled out of highway-diesel to make Ag/off-road diesel fuel.

South Side, your second question about preventing the problem is one that I may not be able to answer to your satisfaction, but that won’t keep me from trying.  Back in the “good old days,” I would have told you to put a double dose of gasoline stabilizer in a really full tank of gas, run the car for a good ten minutes to make sure that the stabilizer was everywhere in the fuel system, and then store it.  Twenty years ago--when leaded regular was still available--I put a 1946 Chevy pickup in storage with a mix like that in the gas tank.  After over two years of storage, it started right up and ran fine.  That might work with today’s gas if it is stored for a year or less, and if it is stored inside.  If the storage lasted more than a year with that mix in the tank, I would siphon out or remove as much of the old gas as I could, and then fill it with fresh gas before trying to start it.

That still might not work with today’s gas.  A better plan for long-term storage with today’s gas would be to drive the car until the tank was almost empty.  Then, add one full dose of gasoline stabilizer, and either drive or run the car untilit stops.  In short, empty it out and try to store it inside, so there will be less of a water condensation problem in the gas tank.  There are also a lot of other things that should be taken care of before any storage--like the battery, the tires, the chassis, and the exterior, just to name a few.

There is one thing that would be even better than any of the previously mentioned things.  Drive the car regularly and make a 5fifty-mile trip at least once a month. After all, cars are meant to be used.

Herr Professor Nuzanbolts