Is anyone burning Ethanol in their RM?

Is anyone out there burning e-10 (or even e85) in their Roadmaster? What's the mileage hit?

Is anyone out there burning e-10 (or even e85) in their Roadmaster? What's the mileage hit? The “mileage hit” would be several miles per gallon. Ethanol burns faster, therefore, requires much more fuel to provide the same level of performance as unadulterated fuel.

I've heard figures between 10 and 20% less fuel economy. I'm burning E85 in my new GMC truck and wanted to ask if any RM drivers have experimented with E10 or E85 on the LT1 to get some real world feedback. I saw an interesting video on youtube today about a non-flexfuel vehicle that had burned E85 for 105,000 miles with no ill-affects. The engine was torn down and showed no abnormal wear. Other sites say that the alcohol will react with rubber, aluminum, and magnesium in the fuel system. Two distinct camps on the subject.

Actually, ethanol burns more slowly, and at a lower temperature. Ethanol and methanol create lower thermal energy but higher gas pressure. Study what makes pressure in a cylinder and you'll discover that heat is only a part of the equation. The burning of alcohol in oxygen creates more moles of byproduct gasses compared to hydrocarbons, thereby creating higher pressure. The thermal expansion is lower, however, so total cylinder pressure ends up being similar. The fact that it burns more slowly has a net result of a lower brake mean specific cylinder pressure with a moving piston, i.e., the slower burn means the alcohol combustion is "chasing" the piston top a little more than "pushing" it.

Now realize that a mixture of gasoline (hydrocarbons) and alcohol will exhibit some tendencies of both. With only 10% of the mixture being alcohol, the only place you'll ever notice any difference is on a dyno. If you lose 10% of fuel mileage by burning E-10, there is something wrong with your vehicle tune or control system.

I've been using E-85 (95% ethanol in warmer weather blends) and have dropped from a peak of 21.2 MPG to 19.4 MPG on E-85. That calculates to a loss of about 10% in fuel mileage. However, with E-85 costing 18% less than "gasoline" I can afford to use more liquid fuel and pay less. Gasoline is costing me 16.8¢ per mile, while E-85 is costing me 13.2¢ per mile driven.

Further, people can argue all day long that it "takes more energy" to make ethanol and it "depletes the food supply" but that's just politically-based double-speak. Perhaps the fact that diesel fuel is pushing $5 /gallon and that most food makes about three trips around the globe before it gets to our tables has more to do with food prices than corn. Perhaps the fact that much of the additional mash corn used for ethanol production is unfit for human or animal consumption, and that much of this "new" corn is grown in the northern plains, where corn was not formerly grown. This additional mash corn would not have even been available as part of the supply if it weren't for the market provided by ethanol production.

If you actually had an understanding of crop production, you might reconsider that position. If you actually had some concern for the greater good and betterment of mankind, and protecting the "limited" food supply, you'd probably be driving a Schwinn. Once you understand that out of that $5 box of Kellog's Corn Flakes (which is presumably mostly CORN) the cost of the corn itself is about 5¢, you might have a handle on where the REAL problem lies. If corn flakes went up 5¢, you might have a valid complaint. Since it has gone up $1.50, you really need to look at transportation cost and corporate greed.

Thanks for the reply Blue Bowtie. I've read lots about ethanol etc and I live in SW Kansas about 10 miles from the largest ethanol plant in the state. I completely agree with you on the double-talk about "depleting our food supply". Most of the corn grown in this area goes to feed beef cattle. My major concern with growing more corn to produce the alcohol is that it will have a large impact on our already taxed Ogalalla aquifer. It takes lots of water to grow corn. From what I'm reading, switchgrass gives a much better return, grows well with our annual rainfall, and doesn't need additional fertilizer. It was also native to this area in the days of the great buffalo herds.

I put about 14 gallons of E85 in my 95 RMS today and then drove it about 70 miles home. I didn't notice much difference, but it did seem to have a little more power when I was passing a car. E85 is $2.99 a gallon here, and unleaded is about $3.84, so I can take a little reduction in mpg. I get a steady 27 on the highway with unleaded, so I'll have to see what happens with the ethanol.

Yes, I've always have put E-10 in my RM. My parents owned the car before I did and did the same thing also. Can only get E-10 out in these neck of the woods but thats alright. Mine has 254000 on it today and still purr's like a kitten. Org engine/tranny and no flaws!!! I love that car to death. My most recent problem was last night actually and thats the rubber fuel line about 6inchs from the fuel filter somehow got a hole in it and that's probably the worst thing thats ever happened to the car since my dad bought it in the late 90's. Great car! Get usually around 28-30 MPG with it.

Interesting but you are replying to a 1.5 year old thread, check the dates before posting, thanks.

Stations in my area are just starting to carry E10 so I really haven't had the chance to do any calculations for mpg. I guess when the changeover is complete that will be the only choice for fuel.One of my other vehicles , a Chevy Uplander seems to have remained constant in it's mpg's according to the vehicle's DIC since I started using the newer fuel blend.