Current fuel formulation situation.

Gasoline formulations have been on a constant pattern of change. The bottom line being that "gasoline" isn't "just" gasoline any more. Since the early 90's, the EPA and other agencies have been seeking zero emissions. Part of that formula for change involves not just the formulation of fuels but the engines that run on these fuels.

Mainly, the concern has been with the automotive manufacturers ability to build cars and light trucks that would hold up to the volatile nature of oxygenated fuel with 10% ethanol added. (As well as other fuel additives and enhancers used by the different fuel refineries.)  

Because of these additives, fuel has an approximate storage life of about 90 days from the time of manufacture. Think of the stability of gasoline being similar to soda pop. Open a bottle of soda pop and watch the bubbles form. Eventually it goes flat.

So, the automotive industry designed and installed pressurized fuel tanks, vapor recovery systems, computer controlled fuel & ignition operating & monitoring systems, and fuel handling materials resistant to these and other added chemicals.

Unfortunately, boats do not have much of this new technology and older boats will have to be updated and retro-fitted to run on these new fuel formulations. 

In the long run, some issues will be hard to resolve. For example, current Coast Guard regulations do not allow pressurized gas tanks.

What we know so far. [09.04.2007]

Although we had done a lot of testing and research on this situation, we would rather refer you to some other company web sites  who have performed research on this same topic. (Note: the links blow open in a new window.)




As we find the time, we will add more information to this page showing examples and test results. We felt is was important to get the word out, even though we are not fully aware of all the possible ramifications that the current fuel will have on our customers boats. We are aware of many marine engines that will not run properly on the current fuel.  In some cases, engine damage can occur.

In the mean time, there are some things you can do. Change all your fuel filters regularly. Buy gasoline only when you are going to use it. Do not store gasoline over 30 days without adding a fuel storage additive. Do not push an engine that does not seem to be running to it's full potential. Check to see if you have fiberglass or fiberglass lined fuel tanks. If so, Do Not use your boat until you have had these tanks replaced. If you have an older built-in plastic fuel tank, check it for a "brittle" cracking appearance or a "gummy" soft interior surface. Fuel does permeate the shell of almost all plastic marine fuel tanks so, older tanks may not be designed to withstand current fuel formulations.

What we know so far. [Update 03.06.2008]

As Californians have been weaned off of MTBE oxygenated fuel by current Ethanol blended fuels, over the last few years, the instances of MTBE residue clogged fuel filters has lessened. 

Although conditions have stabilized a bit, over the last year, we have seen several significant fuel related issues re-occurring. 1] High levels of water absorption in the fuel, stored in our customers boats, and 2] numerous cases of phase-separation. (In many cases, probably due to the rainy/damp winter, we have had here in San Diego.)

So... fuel quality and filters should be checked before heading out to the water. 

Test run the engine for 5 minutes, before heading to the water front. Remove the water-separating fuel filter, pour the contents into a clean glass jar, and check it for water. Ethanol blended fuel, that has water in it, will have a cloudy appearance. Letting the fuel sample to sit may allow the fuel color to become clear again but be sure to note if water has settled to the bottom of the container. If the sample jar has noticeable layers, after a short time, you most likely have "phase-separation" which means the fuel in your tank may be un-safe to use. 

Feel free to contact us if you have any questions.

An on-going page, last updated: 08.28.2015

As an update to this article we thought we'd discuss:

MTBE and any boat fuel tank.

The State of California was the first to ban the use of MTBE oxygenated fuels when trace amounts of MTBE were found in our streams and rivers. 

This brownish substance, when dried, has a tendency to cling to the sides of a boats fuel tank, similar to a "bath tub ring". Unfortunately, ethanol blended fuel will loosen this particle matter and carry it through the fuel system. Besides clogging filters, the needle and seats of carbs and fuel-vapor tanks on fuel-injected engines can stick due to an accumulation of MTBE particle matter at the seat.

Fuel filters will not catch all of the MTBE particle matter.

So... it may cause clogging at other locations like injector screens, needle and seats, etc.  It can also cause the armature on electric fuel pumps to stick. Tapping on the pump with a screw driver handle may get it to run a few times but, eventually the pump will have to be replaced.

More to come...




Aquarius Marine

9384 Frost Mar Place
San Diego, California  92121

Store: (858) 866-1525
Fax: (858) 866-1527

Email Us here. 


Floyd Design

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