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!! Can run what ever fuel or mix I want and the ECM will adjust for it.
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%.
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.
There is no reason why they couldn't. It was actually quite easy to do with EFILive, just a couple of tables to change and a 45 second reflash of the ECM.
The sensor cost me $74, the pig tail was $15, the hose I made up with push lock connectors was $65 and the injectors where $180.
Trifecta certainly can tune this the exact same way. I know Vince did a full Flex Fuel conversion on his Cruze. I have the injectors sitting on my desk and I was all set to do the same thing. However, locating the fuel sensor from the Buick Regal was annoying. When I tried it was on GM Parts Direct back order. I waited 6 months and the back order was never lifted so I cancelled my order. I will probably revisit the project when my powertrain warranty is up. Screwing with e85 doesn't do yourself any favors in the warranty department and if you don't know what you are doing you can f something up real quick!
I didn't have any trouble finding this sensor on Ebay, in fact I bought two of them to see if I can use the other on on my turbo truck to make it FF as well. The price did go up though. The list price is $112.86 which is still a LOT cheaper then the ones they used to use on my truck. They are like $350 and prone to failure.
Well I filled it up with E85 tonight. Wast just under 3/4 tank so only took 5gal of E85. Watching my scanner, it changed to 27% E85 and AFR dropped down to about 13.20 like it should. Seems to run pretty good. The E85 was .79 a gallon cheaper then 93oct. I'm leaving to drive from Texas to WY tomorrow so I'll see how it does on at least this first tank with a mild mix of E85.
Lead the way KB. This is how the DSM community got so big. It took years and years for some of these guys to come up with this stuff. Our big advantage is that all of our ECMs are programmable. On the DSMs only the first year of the new model were EPROM.
I would like to see what the drop in MPG is with straight E85, as of today E85 is only 10 cents a gallon less than 87E10. It's 50cents a gallon less than the 91(no ethanol) has I usually run. 50cents X 15.6gallons = $7.80 saved per tank, however if MPG loss is as low as EPA indicates on other cars I'm not sure I would save any money.
I did drive a 2010 flexfuel Impala for a few weeks and even up to 50% tank of E85 saw no significant loss in MPG. Have read similar real world results with Flex fuel Tahoe/silverado's too.
Well, I finished my road trip from Texas to Wyoming and here is my fuel stats for the trip. This was mostly highway 65-80 with some mixed in city driving. I drove the car as I always would and didn't try to do anything to fudge the numbers. My EFILive V2 shows the % of E that is currently going through the sensor, so I get a pretty exact reading of the amount. The lower numbers are strait pump 93 with up to 10% E.
1'st, 27% E... 365 miles, 29.5 mpg (added 5 gallon of E85 to pump 93 to test it out)
2'nd, 12.5% E... 326 miles, 32.6 mpg (pump 93)
3'rd, 9.5% E... 492 miles, 33.7 mpg (pump 93)
4'th, 75.1% E... 354 miles, 28.3 mpg (14.6 gal of E85, was almost out of fuel!!! lol)
It does feel quite a bit stronger on strait E85 and I think there is even more power to be had with some more tuning, maybe even some more MPG's with a little more timing in the cruse area of the tune.
I was able to fill up this last tank again with strait E85, so should be even closer to 85%. I currently have only 2 stations that sell E85 up here and both are in a town 70 miles away, so probable won't fill it this next time with E85 unless I happen to be near there.
I notice a price difference of 50 to 90 cents a gallon between E85 an 91/93 so I think its worth it. I still think a 25% mix of E85 and 85/87 will be my most cost effective formula for most performance and best MPG's
Ok, so I've been driving the car a lot, put 3500 miles on it in the month I've owned it! lol and got to run a few tanks of e85 though it and a few of 91/93. Been mostly highway since I'm in Wyoming right now and its a trip to go anywhere! lol. But this is what I'm seeing.
Strait E85 (about 80% on my scanner) Seems to average around 28-29mpg's and is around 3.19 a gallon here. So fuel cost is about $.11 a mile.
Strait 91 (all I can get up here and shows about 9-11% E on my scanner) Seems to average about 34-35mpg's with the same driving conditions. It's about $3.89 a gallon, so fuel cost is about $.11 a mile too.
Pretty much a break even, just can't go as far on a tank of fuel. I will say, it seem to have more pep on the E85.
Another thing I noticed is my DIC mpg's is more accurate with the E85 then with the Gas, with E85 it is consistently about 1mpg high and with 91, it is about 4mpg high when compared to hand calculating it. Thought that was interesting.
Ya, I was pretty happy with the E85. Once I get back to Texas, I'm gonna run it some more since it's only about $2.79 a gallon there and I suspect with more city driving, it will be around 25mpg and I'm still good with that since my other two trucks get less then half that in the city, lol.
You need to log a run at full throttle all the way to the shift at full RPM to see what your max duty cycle is. It goes up as RPM goes up. I need to get my Duty Cycle PID setup and see where mine is, but I'm back to strait gas this tank so will be pretty low.
As far as the 42lbs Bosch injectors Vs Stock one's, the DIY install thread on them claimed they got better mileage with them cuz of better spay pattern/atomization, but I didn't really notice that. But then again, I had only run a couple tanks of fuel though my stock Cruze before I started doing all the mods, lol. I'm an auto trans too, so my mileage is lower anyway. I wouldn't think they would really be cost afective if you didn't plan to run E85, but that just me.
Is there any advantage to doing this to a gas Cruze that has no intentions of using E85? Will it allow the ECM to make better timing and/or air/fuel ratio decisions based on the ethanol content of ordinary gasoline?
As far as the 42lbs Bosch injectors Vs Stock one's... ...I wouldn't think they would really be cost afective if you didn't plan to run E85, but that just me.
YES! I forgot to mention that I was interested in just the sensor upgrade, not the injector upgrade. If I never planned to run E85 I would have no need for the added fuel capacity of the larger injectors.
I would still be interested in learning about the advantages of installing and programming for just the Ethanol sensor. How does the 1.4T adjust for Ethanol content? Is it just done by correcting the fuel trims? If this is how it happens, is this an accurate method? Are there separate fuel tables pre-loaded in the ECM for Ethanol content based corrections, or is it a simple offset of injector pulse width (or something like that)? What else changes with the Ethanol content... spark advance, anything else?
Sorry about all the questions... I'm an uncurable information H0.
I just read the thread on EFILive and I wonder if that guy Boost is on here he claims to be the Fastest Cruze in Florida I wanna see video and pictures lol.
I would love a full write up on the conversion! I'd be very interested in doing it since the college I'm going to be going to has a gas station with e85 right by it.
Something nobody mentioned or discussed...was other modifications that the true flex fuel vehicles have beyond just engine management. E85 is significantly more corrosive than the regular gasoline with up to 10%, and even that is corrosive, just less so.
Everything that touches the E85 from the tank to the injectors has to be corrosion proof or it will eventually become a problem.
I was interested in doing this also when we had the PT-GT. E-85 powered SRT/4s were dyno-ing 400 ft-lbs torque at the wheels. Hand grenading the transmission in the turbo clown car kinda' scared me off. I'm pretty certain the 41TE transmission was not built for the 245 ft-lbs Chrysler rated the engine at (several people put down more than that to the wheels stock....Chrysler sandbagged that number)
The only effect E85 had on our actual flex fuel 3.6 Pentastar was a reduction in fuel economy. :angry: Down from about a 19-20 average to a 15.something average. No extra "peppiness" nor any reduction in throttle response.
Once this is turned on is the % ethanol one of the outputs of the OBDII connector? Wondering if I am using Torque if I can bring it up to see it? I have access to E85 and would like to get a mix around 35% and run it.