E-85 Compatibility

[Big Jim]

I had a lot of experience with M85 flex fuel cars, but have had limited involvement with E85.

It is the memory of the potential problems with M85 that adversely colors the perceptions about E85.

Methanol is much more active chemically than Ethanol. M85 required a much more expensive fuel handling system. The fuel pump, lines, etc had to hold up to the aggressive nature of Methanol. E85 does not need to be nearly as robust. I would guess that those parts may even be the same as for Gasoline. Motor oil when using M85 needs to be specially formulated to handle any Methanol contamination. The M85 motor oil was a special synthetic with special additives above and beyond what is needed for normal synthetic to hold up or the bearings took a beating.

Either M85 or E85 must have a device that reads the percentage of alcohol since they are "flex fuel" vehicles, allowing the driver to fill the tank with E85 or gasoline, so that the mix could be any percentage between the two fuels.

The injectors need to be able to handle the larger flow of the E85. The device that reads the alcohol percentage, and the ability to move the tune to any variance must all be present. The fuel handling equipment must be able to handle the higher flow. The fuel handling equipment probably doesn't need much of a change.

And by the way, M85 vehicles run great with E85.

Anyway, that's what I'm aware of. I don't see how they can make all those upgrades for $50.00 a car.

 

[Rara]

The differences on a flex fuel vehicle are not extinsive, but they are critical.

1. A sensor that detects the level of ethanol in the fuel.
2. Appropriate choice of lining materials in all fuel lines etc.
3. Larger injector sizing
4. Different calibration maps based on the signal returned by the ethanol sensor
5. Upgraded valve and seat materials (not always necessary depending on the original engine operating conditions)

That's pretty much it if you don't count the FFV badging. The sensor is the bulk of the cost difference in a new vehicle, though in some cases #5 can get a little expensive depending on the material required to keep the wear at bay. Case in point, Ford's standard 5.4L 3V gasoline engine uses an exhaust valve made from a relatively high grade of stainless steel and it works very very well. But, when you try to run E85 in that engine with the same exhaust valve, you wear out the exhaust valve and the seat in the head rather quickly, and it never passes an engine test. Change it out for a similar valve, but made of a higher grade Nickel based material (Inconel) and suddenly it passes the engine tests again and wear is back to normal. I hardly think its a coincidence that this is exactly the strategy Ford uses in production . . . and all of the other engine manufacturers around the world are the same way. Unless the base gasoline engine already uses a high grade valve for some other reason, the E85/FFV version will always have either a higher grade material, or a higher surface hardness finishing process (such as seat hardening, or nitriding) in order to last long enough to be useful.

 

[Rara]

Gas is already 10% ethanol these days, and while ethanol is more corrosive than petrol its not going to eat through the engine block or valves.

Are you really that dense? It has nothing to do with the corrosiveness of the ethanol. And engine blocks? Nice strawman argument there; no one even mentioned engine blocks and you should be ridiculed for even implying that anyone did. The extra wear on the valves and seats is because ethanol has significantly reduced lubricative properties compared to gasoline, both before and after they are burned in the cylinder. The lack of effective lubrication on the intake and exhaust valves means they grind much harder against the seat material pressed into the cylinder head and wear significantly faster, sometimes exponentially so.

Again, don't ever try to speak authoritatively on subjects you don't have the slightest clue about.