You have almost two gallons of ethanol in the tank. If you have a 20-gallon tank and you buy regular, you can also be getting up to two gallons, (10 percent) of ethanol. Most mid grades still have ethanol too so you've added even more. You need to use a full tank of premium with no ethanol, unless you can find a lower grade with no ethanol, to dilute what you have already. Assuming a 20-gallon tank, you now have ten gallons, two of which are almost all ethanol, and another eight gallons which could be as much as another 0.8 gallons of ethanol. Round that down to 2.5 gallons of ethanol in ten gallons of fuel. That's 25 percent in a car that's designed to run on no more than 10 percent ethanol.
At this point before you assume there's a problem that needs to be diagnosed and repaired, fill the tank with ethanol-free to dilute what's left. If the running problems clear up, just continue filling with the proper fuel. If you still DO notice a problem, run out as much fuel as you can stand, then as you add the right fuel, the symptoms should go away.
I wouldn't wait though to fill the tank now with ethanol-free fuel. Ethanol doesn't have the lubricating properties found in gasoline. That's an issue with valve seats. Ethanol is very corrosive too and will eat rubber parts. Jay Leno has written an article about all the problems he was having until he started using ethanol-free gas. Also, if I remember correctly, ethanol burns hotter than gas but produces less power. Running it for too long can promote burning the valves.
If you own a car that can use E-85, there is such a major drop in fuel mileage due to its lower energy, that most people say it has to be at least 50 cents a gallon cheaper than gasoline to give the same cost per mile.
Sunday, April 12th, 2015 AT 12:59 AM