4/22/01

Once again I'm covering old ground. This time rather then in the "BS Tip" column, as an editorial, because it's obvious there are knuckleheads out there who just don't get it. Once again, my purpose here is to find a way to convince those who are a little slow at grasping new concepts. For those of you who classify, understand this, I consider myself to be a slow learner, I don't easily forget once learned, but I get there slowly.

So here I am again, talking about the evils of allowing fuel to get old. If you want to review my previous "BS Tips" on fuel, the first is at "Fuel, it ain't gas anymore", from 2/3/00. The second is "Fuelin Around with Designer Motor Fuel", from 2/24/01.

In the past I've tried to describe how fuel goes bad by comparing it to milk getting sour, or old skunky beer. Well I think I have a better way. Liquid fuel does not burn, only the vapors coming off of fuel burns. To make more use of the fuel, to burn it more effeciently, modern fuel is designed to vaporize much faster. Compounding this is that it is very UV sensitive. Many fill cans these days are plastic and if left in the sunlight, many UV rays will pass through the plastic. This causes a chemical change of some of the ingredients in fuel in a matter of hours. These changes appear to be of a nature which speeds the process of going stale.

But the vaporization is where I want to try to set a better example of what happens to fuel. Why is it some folks can keep their fuel for a couple of months with no troubles and others after just a couple of weeks? The 30 day advised limit for fuel age is a guideline, a general limit that works well for most. The difference begins at the pump. Discount fuel isn't going to be of the same quality as your major brands, even if it starts that way. The major brands add different ingredients and the fuel is probably fresher when you get it. The discount chains may be getting fuel from storage tanks that have been there a while. It's hard to say. What is for sure is the major brands offer you a better chance if the fuel gets a little old.

How you store the fuel is the biggie. As mentioned before, keeping it out of direct sun light will help a bunch. What gets a lot of folks in trouble though is that little vent cap on your fill can. Is it busted off? Did you forget to snap it back on or to tighten the main cap? What about those spouts with the flip cap. Is it missing or do you fail to snap it back in place.

OK, lets forget the sour milk and skunky beer. Think of fuel as your favorite soda pop. Take that cola you're drinking, set it on the table with the cap off and come back to sample it in 24 hours. Is the fizz gone? You betcha. And that's exactly what you do when you leave the caps off your fuel fill can. The fuel vaporizes just setting there but if the caps are on tight, they're contained. Once a certain level of pressure builds in the soda bottle, or fuel can, vaporization stops. Eventually from popping the cap, the fizz will go away anyway but the idea is it gets used up before it does. The same holds true with your fuel. Does this make sense to you slow learners out there?

Take it from someone who understands about learning slow. Back in the early 90's when we started seeing these problems I didn't believe it either. Hey, I grew up in the era of true muscle cars, 105 octane pump gas and the gas was good for months. It didn't come easy for me to see the big blocks die and it took a while for this new designer fuel concept to sink in. We first saw the problems with the OHV engines that were relatively new to the lawn and garden market. They have lighter valve springs and tigher clearances which tolerated old fuel gumming very poorly. We blamed it on the engines and were soundly told to bite off, it's the fuel. The engines manufacturers were even a little slow to understanding the problem as they couldn't really tell us why but they knew it was a fuel problem and not the engines. Problem was the fuel was going through such a rapid evolution in its make up to meet air quality standards that few really understood all the complicatons. That of course just made it all the harder for slow learners like myself to believe it was true. Rest assured, it is.

Today, most engines are OHV and they all have more sensitive carbs with tinier jets which tolerate old fuel poorly. These newer engine designs have the same purpose as designer motor fuel, less emissions and better air quality. It useless to argue the merits of making a lawn mower engine meet smog regulations, the fact is those regulations are here, and so is the need to keep your fuel fresh.

Lets go over the precautions once again.
1. Store your fuel out of the sun.
2. Make sure all caps are secure and tight.
3. Use quality fuel from a busy major national retailer.
4. Once a month, dump what is left in your fill can in to your cars tank to assure it doesn't go bad or to waste. Don't do this if your car or truck is diesel.
5. When your equipment is going to be out of use for an extended period, Winterize your engine.

Don't loose your fizz.

LMRM; Bob :<=