Originally Posted by 427-6spd
The 11 doesnt need the sensor. The algorth works fine. Id be willing to bet the 12-14 dont either but dont have one on hand to alter.
The 11 doesnt need the sensor. The algorth works fine. Id be willing to bet the 12-14 dont either but dont have one on hand to alter.
Well I look at it like this, GM (or any car company) will save a dollar where they can, if the estimation routines were so good and accurate why are they fitting sensors again?
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In late 2011/2012, the EPA decided that the flex fuel algorithm was not appropriate because of the following condition not setting off the correct diagnostic trouble code.
If the vehicle is running on gasoline, but has a vacuum leak, then several drive cycles will set off a DTC.
If the vehicle has the FFV algorithm, is running off E85, and has a vacuum leak, it will adjust what it thinks is the alcohol percentage to compensate (Stoichiometric AFR table references 40-70%), not setting off a DTC. That's why they went back to the sensor. Had nothing to do with the functionality of the algorithm itself.
Ouch! An expensive fix for sure.
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how about mileage e85 compare to 91 pure gas?
My setup is a 356ci with a 260/268 (212/218 at .050 lift) duration cam with aluminium corvette heads and flat top pistons running 11.3 comp. ratio. with tuned port injection and vortec crank pick up and dizzy running a 411 pcm and 60lb bosch injectors, 1.6 ratio roller rockers.For transmission its a 4l65e built with the monster in a box mega ss kit.
All in a 92 chevy ext cab 4x4 pickup with a 98 cab now installed with a third door!
running only e85
Cost wise it worked out about the same, the car uses more on E85, but out here E85 is also about 20% cheaper.
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My first tune got a 20% drop in mileage. Im testing methanol this week and then back to E85. I expect a 5-10% drop by final tweaking. GM can get 0% loss with E85 and their turbocharged 2.0L. Ill do my darnedest to match.
Confirmed? I've never seen a car get close to the 'test lab' fuel economy shown on the windscreen sticker.
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here 91 is 3.44 a gallon and e85 is 2.19 a gallon. been running e85 in my chevy 1500 for over two years now because it runs stronger on e85 even though I take it in the pants on mileage. I figured the high compression and turbo charging of the cruze would have yield a little less of a less of fuel mileage. If the cruze was my daily driver I'd be e-85 it but its the wife and she doesn't like the mileage loss
My setup is a 356ci with a 260/268 (212/218 at .050 lift) duration cam with aluminium corvette heads and flat top pistons running 11.3 comp. ratio. with tuned port injection and vortec crank pick up and dizzy running a 411 pcm and 60lb bosch injectors, 1.6 ratio roller rockers.
Unfortunately the EPA uses an energy multiplier for most of its E85 ratings, so you'll consistently see the 30% drop on the sticker as standard, rather than actual test results.
Buick Regal turbocharged, direct injection 2.0L has consistently shown 0-10% loss in fuel mileage.
The average losses I hear for an NA engine are 20-25% on stock tunes, we've attained 5-15% losses on average.
Many customers report 40% losses in their stock FFV trucks though, but I have not gotten to tune any of these yet.
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