100 octane

[jeepinbanditrider]

IIRC you need a fuel system designed for E85 fuel or you're fuel lines and other rubber parts will degrade.

[altiain]

Chris,

If that were the case, why wouldn't manufacturers tout all of their vehicles as flex fuel friendly? It's a marketing coup - they'd get to advertise that they are more "green" without spending one red cent on engineering.

I'll tell you why - because engine manufacturers have done a lot of testing, and they've found that without making significant changes to their fueling systems, most of their vehicles are not capable of running for extended periods of time on E85 without the potential for damage. Those changes - like replacing rubber seals with Viton ones - cost money. The time is coming when all vehicles will be E85 capable, but now is not that time.

There's a big difference between E20 - which some people are pushing, and which car manufacturers have said for years would void the warranty on non-flexfuel vehicles - and E85.

BTW, that whole comment about designing for higher ethanol concentrations - engine manufacturers don't design for what you may or may not use. They design to the regulations and minimum requirements they have to meet, and not much higher than that (especially if designing higher would cost them more money). True story, different industry - we had several failures on machines with "Brand X" engines in them in Arizona. These were EPA Tier 2 (>750hp) engines, which are required to run on 15ppm sulfur diesel fuel. The fuel onsite was found to be 19ppm on average... and it was causing injector failures. "Brand X" did not warranty the failed engines. Neither did we. 4ppm doesn't seem like much, does it? Certainly not as much as changing a chemical concentration from 10% to 85%...

[Dante]

Information that I was referring to:
http://forums.nasioc.com/forums/showthread.php?t=803341

Lots more good reading in that thread, looks like it's on pg. 51 now.

Chris

I don't buy the premise that it's ok to run E85 in road cars not specifically labeled as flex-fuel capable. It won't necessarily bomb you on the first tank, but long-term it's not going to do you any favors (especially for normal street use, but if it's all you can get to make it out of the desert, I guess it'd do in a pinch, but so would Everclear)...

Anecdotal story - while fetching lunch during one of the autocross events at TMS this summer, I was listening to "Wheels", hosted by the guy that writes the Sunday "Drive" section in the Startle-Gram every week (Dave something?). He was talking about how he has been tracking over the last year or so reports of drivers having a lot of issues with their fuel systems in NEW cars (i.e. <3 years old) that when the dealership tested the fuel in the tank, it showed up as way more than the 10% supposedly in the gas you get at the pump. In these cases, dealers would find 20% to 30% ethanol in the tank. In one extreme case, a dealership OWNER filled up his own E85 flex-fuel capable Chevy Suburban with what he THOUGHT was REGULAR 87 octane (E10). When he tried to leave the gas station, it immediately stalled and would not start. He had it towed back to his dealership, and they found that there was 100% Ethanol in the gas he'd just filled up his nearly-empty tank with. 100%!!!! And it completely stalled out an E85-capable Suburban! After draining a quarter of the tank and refilling with REAL gasoline, it would run again.

So, not to beat a dead horse, but if there was no real preparation required to run E85, why in the world would manufacturers go through all the extra work and COST to make flex-fuel vehicles if they could just say "nah, anything can run E85, go for it." They skimp every nickel and dime, they're not gonna drop hundreds or thousands of dollars into their cost to make a car unless they have to, and don't say it's just for the CAFE loophole. If the SAE thought you could run E85 in any normal car, they wouldn't have setup the requirements they do to make a "flex-fuel capable" car.

Point is, E85 will destroy natural rubber and cause dissimiliar metals to corrode at junctions. I guess if you're just going to overboost the snot out of your Impreza and ditch it at 40k (after putting it all "back to stock" for the next sucker to deal with), then yeah, go for it, run 60 pounds of boost with E85 and have fun with it. But it's still not healthy for your non-flex-fuel car. </rant>

[goofygrin]

The main costs associated with the flex fuel vehicles, during manufacture is actually the flex fuel sensors and the programming required to make the car work on anything from E85 to E0. When building a car, it is pennies to actually get the right seals, etc.

I will say that BMW recommends 0 ethanol as much as possible.

Anyway, this thread is way off topic.

[OZMDD]

so... can "regular" cars run 100 octane gas?

[Radio-Active]

I don't know why you would want to unless you have a rally high compression ratio or you are running a lot of boost, something that would cause the engine to pre-detonate.

If you want 104 octane, all you have to do is go get a propane conversion kit and run propane in your car.

[OZMDD]

Thx.