What's the Best Procedure for Changing From MTBE to E-10?
Why the Switch From MTBE to E-10?:
While MTBE has been the standard oxygenating compound in gasoline since the phase-out of tetraethyl lead, the government has determined that MTBE may get into the ground water and can cause cancer. In some areas of the country MTBE has already been replaced by a 10% ethanol (E-10) mixture. Eventually, MTBE will be phased out nationwide and replaced with E-10.
Three Main Problems When Changing From MTBE to E-10:
- Given time and daily changes in temperature, all tanks will accumulate water. When new E-10 fuel is added to a tank with old MTBE fuel and any water, a reaction occurs and a white gummy substance may form that can clog fuel filters and injectors. Water is the critical reactant.
- E-10 has a solvent effect. Old sludge and varnish in the fuel tank will be dissolved, releasing rust, dirt and hard particles into the fuel stream and clogging fuel filters. Clogged filters may strain a weak fuel pump and cause premature failure. Be prepared to replace fuel filters during the changeover.
- Ethanol dissolves some types of resins in certain older fiberglass tanks and introduces them into the fuel stream. This will ruin the carburetors and engine. Do not use E-10 fuel in fiberglass tanks without checking with the dealer first; if they are a problem the only solution with E-10 fuel is to replace the tanks.
How to Safely Change to E-10 (Once You Change, Don't Switch Back):
Make sure to ask the supplier whether they are pumping MTBE or E-10 fuel. Use up all the remaining old fuel, then use a paste test to check the tank for water contamination. If there is more than 4% water, drain the tank or have it professionally cleaned.
K100 will totally encapsulate water at a 1:1 ratio. Add enough K100-G or K100-MG to encapsulate any water remaining in the tank before adding E-10 fuel. It's critical to use enough K200 to encapsulate all the water.
In vehicles there is no way of testing for water, so start using K100 before switching to encapsulate whatever water may be present. Use up as much fuel as possible, then for the first treatment double the appropriate amount of K100 for your size fuel tank before filling with E-10 fuel.
Use K100 continuously to prevent phase separation. If phase separation has already occurred, K100 will not totally reverse the separation.
After the switch, if the engine is hard starting, has poor performance, lack of acceleration and/or lower maximum RPM, sludge is probably clogging the fuel filters, injectors or carburetors. Treat the fuel with a double-dose of K100 and change the fuel filter. Wait about 30 minutes for K100 to encapsulate the water and dissolve the sludge. The engine should now start, though it might stumble at first. Set the engine(s) at fast idle and run until it audibly runs more smoothly.
K100 also contains an organic lubricating agent. This is not a substitute for pre-mix or auto-inject in 2-cycle engines, but will aid in fuel system component life and help prevent cold-start cylinder wall scuff.