Chevrolet Cruze Forums banner

True Flex Fuel Cruze

35185 63
So I converter my Cruze to a TRUE flex fuel car today. I installed the 42lbs/hr Bosch "green giant" injector (stock are 24lbs/hr) along with an actual flex fuel sensor and tuned my ECM with EFILive, so I now have an actual flex fuel Cruze!! :D Can run what ever fuel or mix I want and the ECM will adjust for it.

This is the write up I used on EFILives forum showing how to do this.
Chev/Holden 1.4L Cruze E85 FlexFuel Conversion

Here is the sensor I installed in the fuel line so the ECM know how much ethanol is in the gas. You can see on my V2 where it's reading 7.8% ethanol right now and commanding an AFR of 14.24. Which is right since I run pump 93oct that contains up to 10%.

Vehicle Car Engine Auto part Family car
Electronic device Technology Text Gadget Font


Time to put some E85 in it and see what it does. I did this so I can run cheap 85/87 gas and mix in a little E85 (105oct) and get the performance of running 93 but with less cost. I think I can still get close to the same mileage with only about a 25-30% mix.
61 - 64 of 64 Posts

·
Premium Member
Joined
·
272 Posts
I feel like most of you are missing the point in flex fuel. It's got less gasoline in it, so sure you might see a reduction in fuel economy, but the emissions of burning the alcohol are much cleaner than that of gas.
I have not sat through a chemistry class in years, but help me out with that logic. My fuel injected motorcycle for instance gets 42 mpg with 91 octane fuel with ~10% alcohol. It gets ~50 mpg with good 91 octane non oxygenated and no alcohol fuel, so that is about 20% better. So if it is 10% alcohol and I use 20% more fuel how is that an improvement? I do realize that 10% of the 20% or .02% of that is alcohol but that does not seem like a gain. Anyway you do the math and show it here for us to see.
 

·
Premium Member
Joined
·
557 Posts
What most don't like is the lower MPG running E85, AKA FlexFuel. Around here it is still less expensive to run FF over 93. Sure MPG might drop from say 32mpg down to 25mpg but if you calculate, there is a cool app for this called Flex Fuel Calculator. You put in the MPG and price of the FF and the MPG and price of 93 and it will calculate the difference and show you the cost. The difference here between FF and 93, it is still less expensive to use FF.

Plus I like the benefits of it burning cleaner. My used oil analysis all started coming back with improvements once I started mixing in FF into the vehicles. So for my non FF vehicles I usually mix it 40/60, 40% FF and 60% gas.

I have run 100% FF in my 2002 Silverado, it runs great on it but after a full tank it kicks a lean code on both banks. So I just mix it in. I'm considering converting it to FF. Now on our 2011 Acadia, with the 3.6 VVT and direct injection, it will run 100% FF with no codes and it is not a FF vehicle.

I also like the way the exhaust smells. It has a sweeter smell.
 

·
Premium Member
Joined
·
272 Posts
I can't and don't disagree on what can be a lower cost, I have a local station that sells E85. I have no issues with a flex fuel vehicle and like them because the fuel has a higher octane rating than the 91 octane I can get locally. I like the fact it is a renewable resource. That is why I am getting the conversion for my Cruze.

What I don't get is how can an E10 or E15 blend be better for the environment when I have to burn 20% more fuel with E10 or E15. If I replace 10% of the bad, with 10% of the good, but have to burn 20% more of the bad, as in my real life example above it seems I have used more of the bad. I just don't get the logic. I have read reports from the University of Minnesota stating the same issue. You need to up the the content to an E30 or E35 which gets the same gas mileage if not better then an E10, in a properly tuned car. Then you are replacing 30% of the bad with 30% of the good and the gas mileage is still ~ a 20% decrease so you have come out ahead in that case.



What most don't like is the lower MPG running E85, AKA FlexFuel. Around here it is still less expensive to run FF over 93. Sure MPG might drop from say 32mpg down to 25mpg but if you calculate, there is a cool app for this called Flex Fuel Calculator. You put in the MPG and price of the FF and the MPG and price of 93 and it will calculate the difference and show you the cost. The difference here between FF and 93, it is still less expensive to use FF.

Plus I like the benefits of it burning cleaner. My used oil analysis all started coming back with improvements once I started mixing in FF into the vehicles. So for my non FF vehicles I usually mix it 40/60, 40% FF and 60% gas.

I have run 100% FF in my 2002 Silverado, it runs great on it but after a full tank it kicks a lean code on both banks. So I just mix it in. I'm considering converting it to FF. Now on our 2011 Acadia, with the 3.6 VVT and direct injection, it will run 100% FF with no codes and it is not a FF vehicle.

I also like the way the exhaust smells. It has a sweeter smell.
 

·
Premium Member
Joined
·
557 Posts
I can't and don't disagree on what can be a lower cost, I have a local station that sells E85. I have no issues with a flex fuel vehicle and like them because the fuel has a higher octane rating than the 91 octane I can get locally. I like the fact it is a renewable resource. That is why I am getting the conversion for my Cruze.

What I don't get is how can an E10 or E15 blend can be better for the environment when I have to burn 20% more fuel with E10 or E15. If I replace 10% of the bad, with 10% of the good, but have to burn 20% of the bad, as in my real life example above it seems I have used more of the bad. I just don't get the logic. I have read reports from the University of Minnesota stating the same issue. You need to up the the content to an E30 or E35 which gets the same gas mileage if not better then an E10, in a properly tuned car. Then you are replacing 30% of the bad with 30% of the good and the gas mileage is still ~ a 20% decrease so you have come out ahead in that case.
I see your point. I have yet figured out what specific blend nets me the best economy. I have noticed that my economy doesn't take a hit at a lower blend. I just have not found that point and been able to keep track. I plan to but right now with work it is hard since I don't drive much but a mile to work and back for the next five months.
 
61 - 64 of 64 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top