Wednesday, January 21, 2009

Tank #30

I filled up at Meijer last night.

I got 4.008 gallons of E85 at $1.80 a gallon.

I got 10.512 gallons of 87 at $1.90 a gallon.

My new tank is 26.37% ethanol and 91.57 octane.

The last tank finished at 21.5 mpg at 25 mph average speed. The awful weather is reflected in that awful mileage!

4 comments:

Joeypete said...

Hey Buzz...just curious, how do you get such exact measurements of your octane levels?

buzzcut said...

Yeah, it's a false precision. Just doing the math, that's all.

87 Octane is... 87 octane. E70 is 100 octane. E83 is 105 octane. I just interpolate for the intermediate grades.

Since I don't know exactly what the ethanol content of the E85 that I buy is, this is not all that accurate. If anything, I'm probably a little low.

Same goes for the etahnol content, BTW. I just calculate it, and it is a little inaccurate.

What I really need to do is get an ethanol sensor from an old Ford Taurus and hack a microcontroller to read it. Then I'd know exactly what I'm running.

Sadly, when they come up on eBay, those sensors are really expensive.

Joeypete said...

Oh ok cool! I was just wondering because I've just been guessing on mine.

buzzcut said...

I've got a spreadsheet that I use to keep track of everything, so that I don't need to do the math every time I fill up.