E85Forum.com

BlackNGoldRules · Joined: 01 Aug 2006 Posts: 21 Location: Bethel Park, PA

I'm taking a trip from the Pittsburgh area down to Busch Gardens Virginia in about a month. PA has plenty of E85 stations but Maryland only has a couple and Virginia I think has just one! So, I'm obviously going to have to go back to regular gas for this trip after using straight E85 for the past several months. Should I slowly mix regular gas back in over my next few trips to the pump or would it be OK to keep using E85 all the way up to my trip and just stop cold turkey? Man, you would think with all of the preaching our gov't does about alternative fuels that there would be more E85 stations down that way! Another case of them not practicing what they're preaching, especially in their own area of all places! Anyway, would like your opinions on this. Thanks!

Alcohol · Joined: 17 Apr 2007 Posts: 634 Location: Central Wisconsin

BlackGold-- if this is a factory flex fuel vehicle there is no reason to blend back down. They are programmed to look at the fuel sender (tank gauge) when you turn the key on and if the gauge goes up about 25% in volume- they will then recalculate the fuel blend. Within about 5 miles of steady run time the computer will have it dialed in to the new alcohol level. It works similarly if the FFV has the older "real" alcohol sensor- only quicker.

However -If you are running an aftermarket kit or simply use E85 w/o any modication on a non-flex vehicle - then there may be some benefit to blending down more gradually to allow the computer to adjust more slowly.

On my FFV's I have done both- blending down and doing radical change. It does not matter as long as the ECU has the latest programming in it. Some '06 Impala's with the 3.5L needed a factory update as the original ECU programming had an error in it. Some 5.3L GM's in '06 and '07 also needed the free update programming too.

What are you driving?

BlackNGoldRules · Joined: 01 Aug 2006 Posts: 21 Location: Bethel Park, PA

Alcohol · Joined: 17 Apr 2007 Posts: 634 Location: Central Wisconsin

No need to gradually blend back on that one- I believe that one has the real honest to goodness alcohol sensor and should adapt quickly. One tip with any FFV-- shut them off while filling (key out) and when you restart, run them for at least 5 miles before you shut them off. This helps avoids potential miscalculations on fuel %.