Monday, September 26, 2016

10,000 miles on ethanol blends

So it's been 10,000 miles since I started this experiment of mixing E85 with straight 87 octane gasoline (E10, really) to make a higher ethanol content blend.  I've averaged about E30 during this time, going as high as E40.  I have not had one drivability or reliability issue.  Not one.

Again, this car is a 2004 Acura TL with 150k miles on it to start.  It is not a flex fuel vehicle, not specifically designed for high ethanol blends.

There is a lot of misinformation on the 'net about what E85 does to non-flex fuel cars.  Let this blog be evidence that modern cars can easily handle higher ethanol blends (E15, E20, E30), if not straight E85.  By modern cars, I mean everything after, say, 2001.

Considering that the average car is 11 years old, we are rapidly moving to a vehicle fleet that could handle a lot more ethanol in the fuel than is currently available.  If more retailers had E85 and blender pumps, and if the blends were priced fairly, a lot more ethanol could be sold in fuels than is currently the case.

Tank #23

Gallons of E85: 5.023 @ $1.659/ gallon

Gallons of 87 Octane gasoline: 9.172 @ $1.959/ gallon

Ethanol Content of Tank: 38.01%

Octane of tank: 93.43

Savings per tank vs Premium @ $2.459/ gallon: $8.604

CEL on, CEL off

Throughout this tank, the check engine light came on and went off twice.  As I refilled the next tank, the light was off and had been for a number of miles.  I'd say that the CEL was on for half the tank.

~E40 is marginal in this car.  My next tank will be a little lower ethanol to see if we can limit or eliminate the CEL's.

Monday, September 19, 2016

CEL update

The check engine light went off with about 30 miles on the tank... and came back on this morning with about 100 miles on the tank.

D'oh!  I hope it turns off again.

Friday, September 16, 2016

Tank #22

The CEL is still on from the last tank, but with any luck, should turn off soon!

Gallons E85: 5.001 @ $1.499/ gallon

Gallons 87 Octane Gas: 8.708 @ $2.049/ gallon

Ethanol content of tank: 39.51%

Octane of tank: 93.77

Savings per tank vs. premium @ $2.299/ gallon: $8.3548

Monday, September 12, 2016


So my check engine light came on almost immediately with this 43% ethanol tank.  It has stayed lit.

I'm guessing that 40% ethanol is a hard limit for the CEL to light.  On my next tank I'll take it down to around 40% and see what happens.

Regardless of the CEL, the car runs fine.

Wednesday, September 7, 2016

Weird sticker

Saw this on the E85 pump today.  I knew that E85 topped out at 83% ethanol, but I did not know that it could be as little as 51% ethanol.

Tank #21

Gallons of E85: 6.003 @ $1.749 / gallon

Gallons of 87 octane gasoline: 7.660 @ 2.049 / gallon

Ethanol content of tank: 42.99%

Octane of tank: 94.6

Savings per tank compared to premium at $2.549 / gallon: $8.51

Fun with blender pumps

I recently went on vacation with my wife's van.  In Minnesota when gassing up we came across a blender pump, which had E10, E15, E20, E30, and E85 available.

What did I do?  Filled up with E30!

This van has never run higher grades of ethanol before.  It ran flawlessly on E30, and I couldn't even tell if it lost mileage or not (roughly the same mileage before and after).


I got a check engine light on this tank (roughly 37% ethanol).  It lit about 3/4 of the way through the tank, and cleared before I filled up again.

This is the pattern I've seen at higher ethanol levels with this car, the CEL lights late in the tank and then clears itself.

I will be increasing ethanol content on the next tank to see if the CEL lights earlier and stays on.