Tank #11

I filled up at Meijer yesterday afternoon (the low tank light went off right in front of Meijer! Sweet!). Here are the stats:

Price E85: $3.62 a gallon
Price 87 Octane gas: $4.12 a gallon

Gallons E85: 6.007
Gallons 87 Octane: 8.009
Gallons left from tank #10 (@~35.152% ethanol): 2.184

I'm assuming that the E85 is 79% ethanol, 100 octane.

Ethanol content of tank #11: 38.501%
Octane of tank #10: 92.488

Tank 10 finished with a mileage of 26.1. Average speed was 35 mph.

At 38.5% ethanol, this tank is well over the ethanol content that caused the CEL to light on tank #3. At 35% ethanol, tank #10 had almost as much ethanol as tank #3, but no CEL lit.

And as commente Alcohol likes to mention, my estimates of E85 ethanol content is most likely conservative. So I probably have more ethanol in the tank than I have calculated above.

It seems like you need to SLOOOOOWLY build up to higher and higher levels of ethanol. I probably got the CEL on those early tanks because I went from 30% to 40% too quickly.

My strategy now is going to be to increase each tank by half a gallon of E85 each time I fill up. That's why I went from 5.5 gallons of E85 last tank to 6 gallons on this tank. Next tank will be 6.5 gallons.

Commenter Alcohol explains the Check Engine Light

the CEL is often triggered by the trim being out of boundaries rather than actual lean condition.

With all vehicles however- the concern is not likely to be in closed loop operation- the concern likely would be in open loop such as WOT that you might go too lean unless the ECU has a learn ability for open loop. Larger injectors are often used in performance applications to insure full power and stoichiometric conditions at WOT.

Interesting. You know Al, I used to be an actual, honest to god automotive engineer, and I don't know this stuff. How do you know all this?

The Scangauge will tell you if you are in open or closed loop, in addition to trim and O2 sensor data.

I have to think that the way that I drive, I am very seldom in open loop.

Tank #6

I filled up at Meijer yesterday. Here are the stats:

Price E85: $3.15 a gallon
Price 87 Octane gas: $3.65 a gallon

Gallons E85: 5.008
Gallons 87 Octane: 10.002
Gallons left from tank 4 (@~28% ethanol): 1.39

I'm assuming that the E85 is 75% ethanol, 100 octane.

Ethanol content of tank #6: 31.374%
Octane of tank #6: 91.56

Tank 5 finished with a mileage of 23.5.

Mileage increasing tricks

Since cars get worse mileage on ethanol than straight up gas, I've been trying to implement little tricks to improve my mileage and offset the ethanol mileage hit.

For example, pumping up the tires to their rated limit (35 psi) using the cruise as much as possible (even on Indianapolis Blvd!), and keeping it at 65 mph on the highway.

I learned a new trick. My car has one of those "manumatics". It's an automatic, but you can shift it yourself if you want. You pull the stick towards you, and shift up by pushing it forward and pull back to downshift.

I recently learned that when it is in manumatic, the torque converted is locked in gears 3, 4, and 5.

If you drive on the highway in 5th gear, the torque converter doesn't lock and unlock like it does in D. Saabistas report as much as a 1 mpg improvement in highway mileage by driving in 5th gear rather than "D".

I started doing that today. We'll see if I can see any improvement.

Every little bit helps. If I can minimize the mileage penalty of mixing E85 with regular gas, the cost savings is over $6 a tank.

And the CEL is...

...O2 Sensor too lean.

Went to Autozone, they used the scantool to read and clear the code.

Nice little service that they offer there.

Another CEL

Well, I thought that 36% was still too much ethanol. I was right. On the way to work this morning, I got another CEL. I got off and added another 3.592 gallons of Amoco Ultimate to the tank.

So... tank #4 statistics:

Gallons from tank 3: 12.8
Ethanol content of tank 3: 36.435%

Gallons of 93 Octane Amoco Ultimate: 3.592

Ethanol content of tank 4: 30.6273%
Octane of tank 4: 94.31

I'll clear the code after work tonight and see what happens.

Tank number 3

Gallons from tank 2: 13.25
Ethanol content of tank 2: 42.71%

Gallons of 93 Octane Amoco Ultimate: 3.146

Ethanol content of tank 3: 36.435%
Octane of tank 3: 94.74

I just hope that I can clear the CEL code and not have it come back on with 36% ethanol. That's still a lot more than the 30% that worked so well on tank 1.

DAMMIT! Check engine light goes off at 43% ethanol!

Man, that was quick.

71 miles into my 43% ethanol tank, the CEL went off.

I was Cline, starting to go over the bridge over the canal in East Chicago, by Mittal. The cruise was set at 65, and the turbo was spooling up. I'm not surprised that the CEL would come on in that situation.

The car was running well. No hesitation or missing that I could feel.

I got off Cline and hit the BP in Whiting on Indy as soon as I could. I added 3.146 gallons of Amoco Ultimate.

I'll go to Autozone this evening and use their scantool to see what the code is and to clear it.

Another Saabista uses ethanol

An anonymous comment:

I have an '04 Saab 9.3 2T Aero w/6 speed manual non-flex. The preferred fuel for me in it is E20-E30. With 90 octane NL the turbo will only spool to red zone- with E20 it will peg if you nail it and you better get ready for some torque steer. I buy this for about 25 cents less than what 90 octane NL costs. While I have tested E10-E60 in my none flex vehicles and all blends in my flex vehicles for mpg-- I have not yet done this on the Saab. (I picked it up last fall and as a 2wd and low skirt Aero version- it was parked for the winter)

So I'm not the only eccentric Saabista messing around with E85. Cool!

Sounds like Anon is from Minnesota.

My 2.0T has the premium package, which includes the 17 inch rims and skirts from the Aero. I wish I could have gotten the 60th Anniversary package that included the Aero seats. My seats are nice, but the Aero seats are near perfect (and the Convertible seats ARE perfect.)

I guess we don't get enough snow here in the Chicago area to worry about "the snow plow effect" of the air dam. I do scrap the air dam on my driveway every time I pull out, though!

Fun with Ethanol (the E85 kind!)

Usually, fun with ethanol involves getting wicked drunk.

I'm not talking about the kind of ethanol that you drink, I'm talking about the kind that you put in the tank of your car!

E85 is a mixture of ethanol and gas. In the winter, it is 70% ethanol and 30% gas (87 octane gas, I assume), and in summer it is 85% ethanol and 15% gas.

I recently noticed that the Meijer on the Boulevard in Highland has E85. They sell it for 30 cents less than regular.

This got me thinking. I drive a Saab, and Saab makes a version of my car that runs on E85 (called Biopower). Unfortunately, my car isn't E85 capable.

So I started looking into what would happen if I ran E85 in my car.

According to what I could find on Google, you CAN run E85 in any car. Unfortunately, it will cause the check engine light to come on, and may damage the engine and other parts long term.

But it looks like if you mix E85 and regular, in proportions up to perhaps 50% ethanol, you should not get the check engine light to come on.

So I bit the bullet. On the way home from work the other day, I topped off with E85. I got 5.575 gallons in there, which works out to be 30.4% ethanol.

So far, I've driven about 45 miles. I did some "testing" where I floored it, just to see if I could get the check engine light to come on. It didn't come on.

So I'm going to be doing some experiments:

What kind of mileage do I get on E85 mixtures? Straight up E85 should cause about a 30% decrease in mileage, but lower amounts of ethanol should not be as bad.

How much ethanol does it take before you get a check engine light?

Does any other damage occur by using E85? It has the reputation of dissolving rubber and causing metal to rust (not directly, but because it is very hydrophillic).

But again, from what I've found in my research, the Biopower Saab has the same parts as mine. I think the fuel system is made of materials that will survive E85 mixtures.