Gen1 E85 mix results (california)

Technical info on the Pontiac Vibe and Toyota Matrix including do-it-yourself info
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cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Gen1 E85 mix results (california)

Post by cigvibe »

My background is in power tuning where E85 reigns supreme for crazy horsepower results. I have not actually put E85 in a daily driver car because up until this year, the price difference was not worth the potential issues and destroying of engine, fuel lines, or pumps.

For years, I have always wondered what would happen if you just put a splash of e85 with regular gas. Others have done this calling it E15 or E30, the number being the percentage of ethanol you are using.

Since my latest vibe is a beater and gas is now $5.45 a gallon here in cali, I decided to see what would happen if I mix E85 ($3.29 a gallon) with regular gas.

I DO NOT suggest that you do this on your personal car. I am willing to take the risk of damage or failure for the greater good of having data to share with others.

By my calculations, you can run 3 gallons of E85 for a full tank. Data suggests 4 gallons, but I wanted to be on the safe side. I started with 1.5 gallons on a half tank to see what would happen. The fuel trims went positive +5% from the baseline because the car will run more lean with e85 mixed in. I then filled up with gas and when there was space i put another 2 gallons. My fuel trim went to +8% from baseline.

So far, no issues, the car runs fine. I might suggest that it is a little bit more peppy with the higher octane e85 but that could just be my own mind thinking so. 3 gallons of e85 on a full gas fill should be fine. 4 is pushing it on stock injectors.

If you were to put in 2zz injectors, you could potentially go to a higher e85 content.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
Bookworm
Posts: 764
Joined: Fri Nov 05, 2010 11:21 am
Location: Houston, TX

Re: Gen1 E85 mix results (california)

Post by Bookworm »

One thing to keep in mind is that depending on the area, E85 is apparently _not_ 85% ethanol. The rating can go all over the place.
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

I burned through the first tank. My maximum fuel addition (LTFT) was 12% over baseline somewhere around half tank. It then settled at 9%

A full tank of gas at $5.59 would cost $65
A full tank of gas with 4 gallons of e85 would cost $58.50 (E30ish)
10% savings

However, my MPG has gone down due to running more rich to compensate for the e85. (Roughly 50 miles lost). I'm going to fill again and compare, this tank I was idling quite a bit every day using the car for deliveries. Hopefully I will go for longer drives and present a number. I'll average 3 full tanks to come up with my final number.

So the question is, are the savings in cash worth the loss of MPG?

What if we install 2zz injectors that flow 15% more? You could possibly get to a 50/50 E85 mix. A fill up would cost $53 or so but the MPG would be even worse.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

This full tank I went with 8 gallons fuel and 4 gallons e85. Fuel trim is now at 13% above baseline, but now it bounces around a little bit.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
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joatmon
Posts: 10018
Joined: Fri Mar 21, 2003 5:19 am
Location: SMC MD

Re: Gen1 E85 mix results (california)

Post by joatmon »

cigvibe wrote: Tue Mar 15, 2022 12:59 am
So the question is, are the savings in cash worth the loss of MPG?
I'm guessing no. Taken as a single data point neither cost per gallon or miles per gallon tell the full story. To determine if there is actual cost savings, you need to combine the two to get cost per mile. You are going to drive some distance per day, per week, per year, etc. . How much does fuel cost to go that distance?
In your data from last month, you said a 10% cost savings but a 50 mile decrease in range. In order for there to be a cost savings, your normal range would have to be over 500 miles for the decrease to be less than 10%. You also said $65 @ $5.59 /gallon, so that's ~11.6 gallons. If you were getting 500+ miles out of 11.6 gallons (43.1` mpg) do not mess with it, its the best Vibe ever.

When I bought my first 03 Vibe, I went way out of my way to buy a base 5 speed manual, because at the time the 5 speed was rated 36 mpg hwy while the base auto was only 34. And I was actually able to average almost 300K miles over 35 mpg. Sounds worth it, except to go those miles I also had to pay to replace the tranny, and then the clutch, and those costs exceeded the money saved by driving the one that got 2 extra mpgs

There could be other factors that make it worth it, depending on the science of emissions chemistry, or the politics of fossil fuels, which I dare not go in to. ;)
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cigvibe
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Re: Gen1 E85 mix results (california)

Post by cigvibe »

This fuel tank I went with 4 gallons of E85. My previous 3 gallons netted around the same MPG as the 2 gallon test, because I was on the freeway a little more. I am now up to 19% LTFT (My baseline is 7%, so 12% added)

I am finding that my city MPG is pretty terrible, but my freeway MPG is pretty good. Unfortunately, I really only do city travel. Maybe I should get a Prius LOL.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

joatmon wrote: Fri Apr 08, 2022 5:20 am
cigvibe wrote: Tue Mar 15, 2022 12:59 am
So the question is, are the savings in cash worth the loss of MPG?
I'm guessing no. Taken as a single data point neither cost per gallon or miles per gallon tell the full story. To determine if there is actual cost savings, you need to combine the two to get cost per mile. You are going to drive some distance per day, per week, per year, etc. . How much does fuel cost to go that distance?
Since gas here was right at $6 and E85 being only ~$3.50, I was hoping the dollar savings would outweigh the MPG loss. The issue was that I could not put in enough E85. I have been using basically 25-30% e85 which you can do on any car.

I just installed 2ZZ injectors. I have the brown ones which are bigger than the standard 2zz injectors (yellow). Even with my previous E85 mix, it is still pig rich. I am hoping I can get to more than 50% E85 and really get the savings going.


I also found some notes from a guy with a 2003 Corolla in France running 100% E85. Since "petrol" is so expensive, he switched to full E85 with big injectors. On his math, since regular gas is twice the cost of E85, he is still saving money despite the MPG loss.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
Bookworm
Posts: 764
Joined: Fri Nov 05, 2010 11:21 am
Location: Houston, TX

Re: Gen1 E85 mix results (california)

Post by Bookworm »

I'm thinking about doing a single run of one gallon of E85 in a half tank of regular gas, and see what it does to possibly clean up my injectors. (half tank so if something starts to go weird, I can fill it up with regular)
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

I started with 2 gallons on a full tank, (equal to 1 on half).

The difference in LT was slight, but it's going to make you run more lean. You are already having lean issues, so this might be going in the wrong direction :D :D :D

Note that I put in bigger injectors which is now why I am RICH by quite a bit even after adding 4 gallons of E85 to 1/4 a tank. I can't calculate my mix anymore until I start over at empty, but I'm going to mostly likely be past 50% E85.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
Bookworm
Posts: 764
Joined: Fri Nov 05, 2010 11:21 am
Location: Houston, TX

Re: Gen1 E85 mix results (california)

Post by Bookworm »

My thought was simply that the alcohol tends to have a cleaning effect - which is part of why you can mess up engines. The alcohol apparently strips the varnish and sludge all at once, then deposits it into the filter, fuel lines, and injectors.
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

You are right.

I watched a very old video where they took 2 cars one that used E85 and one that used regular gas. They took apart the entire car, fuel pump, lines, motor etc see what negative effects the e85 had.

The non e85 car had lots of dirt in the fuel pump and fuel lines. The E85 car had clean a clean pump and lines and less build up on the valves.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

After finishing off my "E30" Mix, I went to E50. Still way too rich. I am now at 5 gallons E85 to 1 Gallon of 87, plus whatever was left at the bottom of the tank.

Still a bit rich. So it seems that the brown injectors are too big, or they just flow too much because they are china copies. I might be able to actually run 100% E85 with these, but I didn't want to go that far. Also when cold it is really rich, but cleans up after getting warm. I am currently at -7% overall.

I'll be on the lookout for the yellow 2zz injectors.

As far as the MPG, it is going downhill. I won't know for sure until I get my mixture right.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

Another month has passed. Full E85. Have not had an issue. My LT fuel trim is constant at -7%. So I'm a bit rich but nothing the computer can't handle.

My estimate is about 17MPG city. I idle alot for delivery so the number is skewed a little. The car does run awesome though. It is very responsive vs the slug that it was when I first started with it.

Calculations would say that I am not saving any money with e85, but I do enjoy how it drives.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
cigvibe
Posts: 52
Joined: Tue Feb 08, 2022 6:29 pm

Re: Gen1 E85 mix results (california)

Post by cigvibe »

I forgot to make an update. I had let my mom borrow this car back in june 22, and she ended up keeping it as it was reliable.

It has been a daily commuter for her to work. We left the e85 setup in the car and even as gas prices dropped we just kind of forgot about it.

Fast forward to now she mentioned a stumbling issue from a start. I checked out the car and it would struggle to go unless you gently hit the gas.

Full power was OK. I checked the mileage on the car and it has 270K. I gave it to her at 240k a year ago. I was like WOW where have you been going LOL.

I pulled the plugs and 2 of them the metal top portion was missing pieces. The gap was way way out of spec. I put in some new plugs to test and the misfire is gone. To be fair, the plugs were a bit worn when I had it, I forgot all about it when i was trying to figure out what brand I wanted.

However, I remember an issue when I had the car where you couldn't punch it unless the car warmed up just a tad. The computer + E85, it just can't understand what to do when cold and the o2 sensors haven't kicked in yet. She has been just letting the car warm up for 5 minutes before taking off.

At this point, knowing the E85 was successful, I am going to start introducing regular gas back into the system. I am curious now with the bigger injectors what mix will be acceptable without running too rich.

BTW if anyone has a stock set of injectors for cheap or near free, I would be interested in them so that I can eventually put it back to stock for smog.

So if you think E85 will kill your fuel pump, this one went 30k just fine.
Cali Vibe 238k Wave Blue

mods
2zz "brown" 320cc injectors - Full time E85 gas - K&N airbox insert - charcoal filter delete - 3" fresh air duct
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