The owners' manual recommends 89 octane for the automatics and 91 octane for the manual transmissions. It also says that the 5.7 Hemi in stock trim doesn't need anymore than that for octane. Around here, 89 octane usually has 10% ethanol. The owners' manual says that burning fuel with 10% ethanol is OK. My best MPG has been 23 MPG. I was wondering if anyone out there with an automatic has 89 octane fuel that is not formulated with ethanol and have gotten better fuel mileage. I would think that I have driven my car in a situation were I should have gotten the 25 MPG that the factory says that I could get. I know fuel with ethanol does not give as good fuel economy. Anybody got the answer?

 

I put some gas in my Challenger 6 speed about a month ago . Then noticed a sticker that said it had ethanol . I about had a heart attack . Had not seen that at any other Shell station I been to . Asked the clerk inside . She didn't know anything. I had a very bad experence with ethanol back in the 80's . Had a new Dodge 15 passenger Van I hauled workers to work . A station owner talked me into buying his gas with a big discount. Had no problem till months later when I was on vacation for two weeks. The Van sat . And I drove my cars. The first day back to work the Van didn't run right . Then the engine caught on fire . Did alot of damage to the engine. Melted the Thermoquad carb. Had to pull the engine heads off . My insurance investagated . And found the gas and ethanol had seperated . And the ethanol had setteled in the bottom of the tank . And that was where the fuel pick up was. Since it was the gas that caused the damage . They only paid for the inspection . I don't want that stuff in my R/T

 

More realistically, the ethanol probably degraded the seals in the fuel pick-up, the fuel pump or some other rubber or plastic lines in the fuel system an caused a leak.

Not sure where I stand on 10% ethanol nowadays (I can't avoid it anyway here in Illinois) but back in the 80s and 90s, I agree, ethanol in the gas was not a good thing. Cars were just starting to be produced with the proper materials to handle ethanol. The soft parts (hoses, gaskets, seals, diaphragms) used in earlier cars would degrade in the presance of ethanol then leak prematurely. Some of the hard parts would corrode in the presance of ethanol resulting in clogged parts. Combine that with poor quality concrete fuel tanks at filling stations that would leak ground water into the fuel tanks. With regular petrol, any water would seperate, but with ethanol, the water and any other water soluble contaminants would combine with the ethanol (remember high school chemistry??ethanol absorbs water-the reason you use concentrated (and clean) ethanol in the form of Dry Gas) and you could end up with more water and dirt in your car's tank.

Nowadays, cars fuel systems are manufactured to handle - up to 10% - ethanol as described by manufacturers. Filling station underground tanks have also been upgraded to include a proper liner to prevent ingress of moisture and dirt. Also, the amount of fuel we consume today prevents gas from sitting around for extended periods in the underground tanks.

So, don't worry about using todays gas with up to 10% ethanol.

It is presumed that we could even run on 15 to 20 % or higher without any problems but manufacturers have not completed or published results to confirm it. With the inreased availability of flex-fuel cars and E-85 fuel (85% ethanol), often within the same model (only computer programming differences between a flex-fuel and a non-flex-fuel car). The big oil companies don't like E-85 (obviously) so they keep lobbiests busy on hand to highlight any real or imagined problems with ethanol usage in automobiles. Ethanol can run cleaner (less deposits inside your engine), burn cooler (heat hurts performance) and be more fuel efficient if the motor is set up properly (high compression as in 12 or 13:1). But in most of todays cars, including the flex fueled variety, operate in the 9 or 10:1 (or even lower) compression ratio in order to run good on the standard gasoline grades available today (86, 87,89,91,93 octane with or without up to 10% ethanol).

 

Here in Waco, TX I always fill up with 93 octane. I was in Houston in January and filled up at the cleanest station and put in 91 octane with 10% ethanol. The car did not run worth a damn.

 

[:'(] I am a farmer,and a registered tech.I know for a fact that the ethanol does nothing as promised.[:'(] It is all about political,lobbiest mumbo jumbo crap.True,the seals,gaskets,etc,have been upgraded to better handle alcohol fuels,but there is dozens of other problems you can have that I,m not going to get into now.The whole idea that it is better for the enviroment is hogwash.[:'(] Ethanol plants are closing at a alarming rate for dozens of reasons.Them losing funding,and the price of crude,and the price of corn are factors,but only a part of the reason.

 

Around here, Marathon is the most common major brand. Their refinery is just 30 miles from here. All their products, at least around here, says 10% ethanol. Casey's is the most prevalent cut-rate station around here and all their products are 10% ethanol. Ethanol couldn't compete if it weren't for the incentives and breaks. As a fledgeling industry, they should get a break but they should be using this time to improve their product to be competitive on its own merit. If not, it will just be a failure and waste of taxpayers money. Formulate it to produce octane and mileage.

 

In order to be competitive, they need to get away from using corn as the base product. Corn is one of the hardest materials to convert to ethanol. Heck, you and I can not even successfully process corn as a nutritional source (in corn, out corn ). Brazil does a much better job at competitive Ethanol production using sugar cane because sugar cane breaks down easier. Other options for inexpensive US production should include switch grass, sea weed and even grass clippings, but that would force the corn farm subsidies to dry up. And, for the record, the corn currently being used to create ethanol is not edible by US or even third world standards.

Without getting into too many details, Ethanol has been forced out of mainstream by Big Oil lobbying since early on, going back to the early 1900s, or even earlier for home heating and cooking uses. At one point, Big Oil sucessfully lobbied states to enact state transportation taxes such that the transport of bulk ethanol across state lines for resale required fees of up to $2.00 a gallon for Ethanol.

Every time we get into a high oil price ranges, ethanol looks like a better alternative. Then Big Oil starts to feel threatened and they find a way to reduce gas prices to make us all forget about the need for an alternative. Then Big Oil lobbies local and federal governments to tax ethanol further to make it an even less cost competitive option. Then once the Ethanol plants close, Big Oil startes to jack their prices back up again.