EFLEX - Anti-knock properties with different Ethanol concentrations

**slipway** · 05-03-2013, 11:02 PM

ive seen e98 in the us. cant do e100 from the pump, people would be using nozzle as a straw.

**MWP** · 07-03-2013, 12:58 AM

None of this really matters as Caltex will stop selling eFlex by the end of this year

All other sources of E85 seem to have quite reliable 85% content.

**trdee** · 25-09-2015, 09:55 AM

link updated. old one was broken. those who are interested in this kinda stuff should download it before it disappears for good.

**aus jd 2703** · 25-09-2015, 11:55 AM

Originally Posted by MWP

None of this really matters as Caltex will stop selling eFlex by the end of this year

All other sources of E85 seem to have quite reliable 85% content.

Can still buy it in QLD, I think this must have been a rumour started to kill flex fuelled cars?

**MWP** · 02-10-2015, 05:19 AM

Nope it wasn't. Caltex no longer sells E85 in SA.
Only a few United servos sell it now at a greatly inflated price (atm its fixed at 135c/l)

**maj** · 02-10-2015, 11:46 AM

Caltex website still shows a few places in SA that sell it. Can still get it here in ACT no worries.

**RONA** · 02-10-2015, 01:07 PM

Originally Posted by MWP

Nope it wasn't. Caltex no longer sells E85 in SA.
Only a few United servos sell it now at a greatly inflated price (atm its fixed at 135c/l)

To be fair Eflex is 104 ron vs United E85 which is 107 ron.

I have a united servo 2 mins from my house

**MWP** · 02-10-2015, 04:22 PM

Originally Posted by maj

Caltex website still shows a few places in SA that sell it. Can still get it here in ACT no worries.

The website is wrong, they don't

I have the problem that i have now is the only United servos selling E85 in Adelaide are all north of the Airport/CBD.
So thats a ~30min drive each way for me to get fuel

Originally Posted by RONA

To be fair Eflex is 104 ron vs United E85 which is 107 ron.
I have a united servo 2 mins from my house

EFlex tends to be around 70%, which is still plenty.
The effect of 85% vs 70% is almost nothing.

**trdee** · 02-10-2015, 05:01 PM

Not arguing on the ethanol concentration but the RON could also be affected by other additives and the base fuel

**robk** · 02-10-2015, 05:06 PM

Thanks for posting that chart! This is the first time I've ever seen a chart which confirms what I have only ever heard or read.
When running flex-fuel, as I do, I think it's typical to get a tune at 0% ethanol and another tune at ~85% ethanol, then simply let the ECU do a linear interpolation of ignition timing vs ethanol content (or in some ECUs, such as mine, you can specify a non-linear increase in ignition advance as the ethanol content increases).
Given the shape of the curves shown on that chart, it's comforting to know that a simple linear interpolation of ignition timing vs ethanol content is actually 'playing it safe', so there's no need to get a tune anywhere in between 0 and 85 % ethanol (unless you want to get the maximum possible power at every possible ethanol percentage).