Some drivers are blending their own ‘premium fuel’

This week I wrote about the sudden, inexplicable rise in gasoline prices in Southern California, and how much lower prices for E85 ethanol blend is.

E85 is meant to be used in flex-fuel vehicles (FFVs), or vehicles that have been converted from gasoline-only to run on higher ethanol blends. But we’ve been hearing from drivers around the country who use E85 even if they don’t have an FFV. Although E85 isn’t approved for these vehicles, some consumers, enticed by the many benefits of E85 — the price point, the fact that it’s cleaner and made in America — are happily using it anyway.

Older cars might not be able to use higher ethanol blends (what we call regular gas is E10, meaning it has up to 10 percent ethanol) and run efficiently. There’s a potential for damage to engine parts of some older cars. But some pro-ethanol drivers, especially those who own newer vehicles with sophisticated on-board diagnostics (OBD) computers, have reported no problems.

“Both of my gasoline vehicles use E85 and perform flawlessly,” Jeffrey Matthews of Murfreesboro, Tennessee, wrote in a comment to a lively FFF Facebook post this week. “And both pass the annual emissions test with flying colors.”

Cheryl Near, who with her husband Phil co-owns two fueling stations in Wichita, Kansas, that sell both E10 and E85, says some customers fill up with E85, regardless of their make and model.

“We had a lady that had an older model car, before 2001,” Near, who also appears with Phil in our documentary film PUMP, wrote on Facebook. “I went out to ask her if she knew that she was filling with E85. She told me that she did and that she loves it. Her son logged her mileage for her and they found that her car got BETTER gas mileage on E85. Our pumps are clearly marked so if I see somebody filling with E85 in a non FFV, I will go talk to them. They all know and choose to fill with E85.”

Of course, not everyone has easy access to a station that sells E85. (There are 2,639 such stations in the U.S., according to the Alternative Fuels Data Center’s locator, which you can access through our Fuels 101 section.) There needs to be more stations, that’s one of our goals as a foundation.

Even among those who can find the fuel, what if you wanted to use more ethanol than just puny E10, but weren’t prepared to go full bore with E85?

Some drivers “splash blend” E10 with E85; the sensors in the OBD can determine the properties of the fuel in the tank and adjust the oxygen intake accordingly.

“I use 30-50% E85 no problem,” Jason Fritsche wrote on Facebook.

John Brackett, an automotive engineer who also appears in PUMP, wrote in an e-mail: “Since most E85 actually tests as E70-75, and all other gasoline is E10, the blend is usually about E35-E40. This is a great way to make your own ‘premium fuel.’ ”

E85 is technically any concentration between 51 percent and 83 percent ethanol, depending on the season and the part of the country where it’s sold. Because ethanol has less energy content than pure gasoline, drivers might see anywhere from a 15 to 35 percent dropoff in mpg using E85 compared with E10. Which means you’d have to fill up an extra time every couple weeks.

To achieve a certain target level of ethanol blend, you can use one of several smartphone apps to perform the calculations: E85 Mix Calculator is available on both iTunes and the Google Play store for Android. Another is E85 Calculator on Google.