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I'm not far off making the leap into E85 territory. One deciding factor in it for me, is compatability with Caltex E85. I can't be assed travelling to the few independant servos that carry E85, they are just too far away from me. Once in a while, maybe, but not every tank. And if I run E85, I want to run it somewhat permanently.

Now, not so long ago, there were several discussions and concerns expressed within E85 related topics here on SAU - questions about whether the Caltex brew would be safe to use, given Caltex did not want to guarantee the percentage of ethanol in every tank (which was to change between 70% and 85% anyway, depending on summer and winter seasons). This is a non-issue for new cars designed to run on E85, as (from what I'm told) they used sensors to detect ethanol content and adjust fuel maps accordingly (something to that effect). So the consensus at the time of these discussions, was that unless you A. had an ECU with 3D fuel maps, B. tuned your car to run the mix straight after filling up, or C. had about 10 different tunes ready to load after filling up, you should stay away from the Caltex E85.

What are the latest thoughts on this? I ask because I was talking to a Stagea owner the other day, who claimed to use tank after tank of Caltex E85 with no issues at all. He also had a wideband O2 sensor to keep an eye on things.

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I think Scotty NM35 mentioned the change in AFR's on his wideband between the 70% blend and 85% blend being f**k all, as well as the fact that if you've tuned into the sweet spot but not beyond, you won't REALLY have to worry about any damage being done.

e70 on e85 map = running slightly rich which will compensate (with some minor negative things like eventual fouling of plugs perhaps? certainly no detonation)

e85 on e70 map = running slightly lean, but theoretically shouldn't detonate due to increased ethanol content. Will run a bit shitty though, should still be relatively safe.

You're right though, it's not a gamble you can make without a wideband sensor and ability to swap maps on the spot once you see that you're running the "other" stuff. You'd also want to either have your maps somewhat conservative to compensate for a mix in e70 and e85, which could mean you'll have anything in between, or 3 maps - 70, 77.5, and 85% ethanol

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Im running caltex e85 no problems, got a 40kw up top and yeah in regards to the variance in ethanol content if you get it tuned to leave some margin for when the mixtures change you wont have a problem. I got it done at status and trent was confident theres no problem if the tune accounts for the change.

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i have used it and i know someone else from down (or up as the case may be) here that uses it. i havent noticed much change. worst case you get it tuned for E85 and run it on that tune all year round as some have commented their switch from E70-E85 made about 1 AFR difference (eg cruise of 15:1 became 16:1) where as if you are tuned on E85 and it changes to E70 it only gets richer.

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well basically yeah buy a WB02 to keep an eye on things, but the consensus is an E85 tune done with a little bit of wiggle room in the AFR and not 'on the edge' timing wise is fine to use with the varying caltex brew. best to talk to your tuner though and find out what he's comfortable with but personally I wouldn't be too turned off. just keep an eye on the WB02 after fill-ups and you should be fine.

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The conversation I had with the caltex dealer implied that whilst the ethanol content would vary between summer and winter the ron rating would not.

I am going to use wide band just to be on the safe side and some logging over a period of time should make or break what they had to say.

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LOL I was going to say, what's wrong with Noel's post?

Cheers for the advice, it's good to know. Think I'll get a WB sensor and conservative tune, maybe 2 switchable tunes (E70/E85) if I can afford it.

E85 here I come :D

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Im running caltex e85 no problems, got a 40kw up top and yeah in regards to the variance in ethanol content if you get it tuned to leave some margin for when the mixtures change you wont have a problem. I got it done at status and trent was confident theres no problem if the tune accounts for the change.

So you don't have a wideband or anything to monitor AFRs? I suppose if Trent has recommended that then you should be ok. Having to switch maps and buy a wideband etc etc is making converting to e85 just a bit too inconvenient for me atm.

The conversation I had with the caltex dealer implied that whilst the ethanol content would vary between summer and winter the ron rating would not.

I am going to use wide band just to be on the safe side and some logging over a period of time should make or break what they had to say.

Forgive my ignorance, but if the RON rating stays the same can AFRs still be affected? Would be good to get some concrete info from Caltex re: their mixtures

Forgive my ignorance, but if the RON rating stays the same can AFRs still be affected? Would be good to get some concrete info from Caltex re: their mixtures

yer the AFRs will be directly affected by the % of ethanol in the fuel, which if constantly mixxed with the same type of ulp will affect octane rating aswell (albeit not enough to be dangerous), the only way they could lower ethanol content without affecting octane rating would be to mix it with a higher octane ulp

has anyone noted how much an octane booster can actually affect AFRs, as I was thinking if I run E85 as my only tune but then cant find E85 on a cruise somewhere that I could possibly use 98 and some octane booster...

would that work or am I asking for trouble... otherwise I'll be limited to 250ks before I need to find E85 or pay the price get datalogit to change maps over to 98 tune...

yer the AFRs will be directly affected by the % of ethanol in the fuel, which if constantly mixxed with the same type of ulp will affect octane rating aswell (albeit not enough to be dangerous), the only way they could lower ethanol content without affecting octane rating would be to mix it with a higher octane ulp

I see. So is monitoring AFRs and changing maps the only way this caltex fuel is going to work? Tuning conservatively and just absorbing the difference doesn't seem optimal

you can do it on the hand controller???

how? I didnt know you could switch maps through it....

you cant change maps, but you can add/remove fuel etc, to make it safer.... only a bandaid solution to limp home really

At the worst it will involve some minor corrections to your tune once a year. either that or run 2 maps.

As I am to understand it the change in ethanol content will not be random. Merely a summer to winter adjustment.

That will not be difficult to work around.

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