I started wrenching in 1976, and have several decades of experience in this field.
Diesel is the best fuel for TEOTWAWKI, but I cannot afford to switch, and I do not have diesel chainsaw. I store aviation gasoline (Avgas) “100LL” for my chainsaws and generators. This pure form of gasoline does not separate, nor degrade as rapidly as modern gasoline sold are regular gas stations. It is much like gasoline was in the 1960s that contain lead, and has few additives. You can buy it at most airports that cater to general aviation private pilots. If stored in air-tight metal 5 gallons in a temperature-stable environment, it can run an airplane after many years of storage without the use of a fuel stabilizer. Many pilots report the remarkably long storage life of Avgas. Avgas in it’s various forms have been used in automotive racing, and as fuel stock for different blends of racing fuel. And it is highly regarded by those who have used it in snowmobiles to chainsaws.
Storage Containers and Management
Plastic storage containers are oxygen permeable and oxygen degrades fuels, so these are not ideal for long term storage measured in years. The good old metal 5 gallon jerry can is ideal. New versions of this container are expensive and can found in stainless steel! Reduce storage container cost by using less expensive plastic cans for fuels that will be used first and metal cans for feuls that would be used after many years of storage. For chainsaws, just one gallon of gasoline can cut a cord of softer woods. Therefore, one expensive or high-quality air-tight metal can might be justifiable, if the fuel will be used after several years of storage.
However, a good alternative to this scheme is proprietary custom fuels such as VPN (best), or others such as Trufuel (much more cost-effective). These are sold in air-tight metal cans eliminating the need for purchasing such for the purpose of long-term storage of fuels. The high cost of these fuel alternatives are justifiable in my book, if it will be used to run chain saws. I suspect that the reason these proprietary fuels store so long is because they might be using the same fuel stock that is used for Avgas. But, I cannot prove it. Besides Trufuel, the least expensive of this category, and runs around $20.00/gal, while Avgas, in my area, is less than $5, and the national average was less than $6 per gallon, when I last checked. I do have one season’s worth of Trufuel in reserve as a contingency to power a chainsaw.
Avgas does not have the same light volatiles of automotive gasoline blends, so starting could be more difficult in cold weather. It is designed to run an airplane a motor at a steady speed of 2,000 to 2,300 rpm. The lead in this fuel increases the octane rating, cools the valves, lubricates valve stems, and cylinder walls as it was designed to do given the soft metal used for engine valves prior to 1972. It would also lubricate 2 cycle motors. Chainsaws to snowmobiles love it. When converted to a metric for automotive fuels, it has a 96 octane rating, and contains a modest amount of lead, therefore it should not be used in engines with emission controls and catalytic converters. Oxygen sensors in the exhaust system, and the catalytic converters would quickly become damaged. The vehicle would continue to run, but without the benefit of good functioning oxygen sensors, the motor will run rich and fuel economy would suffer. Repairing the vehicle, should it need to pass an emissions test in the future, could be expensive. 100LL avgas can be purchased at my local private airport for only $4.99/gal, only 50 cents more per gallon than non-ethanol premium gasoline that is often considered the best gasoline for long-term storage.
Avgas, Mogas, and Chainsaws
I would use not use ethanol fuel for chainsaws for a variety of reasons, unless there was nothing else. And it would be the least desirable and poor choice for long-term storage as ethanol is hydrophilic and degrades the additives in fuel. ‘Hydrophilic’ means water can be absorbed into the fuel and burned. This both good and bad. Good if it will be run through a 4 cycle motor, such as are vehicle motors, but bad if it will be run through a 2 cycle motor that are used on chainsaws. 2 cycle motors require a specialized oil to be mixed into the fuel. This oil-fuel mixture is used to lubricated the motor and to run the motor. If there is water mixed in with the fuel, the operator would not know this as ethanol absorbs it, and it is carried in the fuel. The water in this fuel is not a good lubricant, as it does not mix as well with the oil that is added and intended for purpose of lubrication. A water-soluble fuel does not carry lubricants as well, as a pure petroleum-based fuel does.
Continue reading“Gasoline Types and Long Term Storage, by Tunnel Rabbit”