# Ethanol Avgas **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 14, 2000, 2:13pm UTC](https://boards.straightdope.com/t/ethanol-avgas/14707 "2000-03-14T14:13:00Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [March 14, 2000, 2:13pm UTC](https://boards.straightdope.com/t/ethanol-avgas/14707/1 "2000-03-14T14:13:00Z")
This is from AOPA _Pilot_, December 1999: > [@](#): > > Great Planes Fuels announced at AOPA Expo '99 that its AGE-85 ethanol-based aviation fuel was to be available for sale by the end of November. The fuel, which is designed as a lead-free substitute for 100LL [that’s 100 octane low lead – J.L.A.] has been approved for use in modified Continental O-470 engines. The new fiel consists of 87 percent ethanol, 12 percent isopentain, and 1 percent soy diesel, and is designed to run in any piston aircraft engine with appropriate modifications. > > Great Planes claims that the fuel will produce as much as 15 percent more horsepower than avgas and double TBO [Time Between Overhaul. Aircraft engines are rebuilt after about 1,500 to 2,000 flying hours – J.L.A.]. The company hopes to certify the fuel for use in any Continental ot Lycoming engine and estimates that conversions for most engines will cost less than $500. In addition, the modified engines will be able to run on avgas, AGE-85, or a blend of AGE-85 and 100LL. Madison, South Dakotoa, will be the site of the first retail outlet for the fuel, which will seel for approximately $1.30 per gallon. I rent the helicopter “wet”, so I don’t know how much avgas costs; but I think that when the article was written it was around $2.00/gal. I’m fairly sure that the reason this fuel was produced was to get the lead out of aviation fuel, but given the recent high prices of gasoline, why not start making ethanol-based mogas for our cars? It would be cheaper and also reduce our dependence on foreign oil. Should this have gone into General Questions? Or is it MPSIMS? ---
**Author:** ![starfish](https://avatars.discourse-cdn.com/v4/letter/s/87869e/32.png) [@starfish](https://boards.straightdope.com/u/starfish)\ **Post date:** [March 14, 2000, 2:53pm UTC](https://boards.straightdope.com/t/ethanol-avgas/14707/2 "2000-03-14T14:53:00Z")
First, gas is not that expensive. For road use, you have a lot of federal and state taxes which push up the price. In the 70’s some gas did contain about 10% ethanol. This died out for lack of consumer interest. Note that the artical states that you have to modify the engine to use it. That will make it hard to introduce to drivers. Gas prices would have to go up a lot to justify the “bother” of converting. Other countries have even higher gas taxes than the US does. Very few bother to stop using gas. There are many alternatives. I believe that Brazil switched to a methanol based fuel. In the 80’s the US government funded research on alternative fuels. We have the technology to make artificial gasoline; it’s just not cost effective now. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [March 15, 2000, 2:01am UTC](https://boards.straightdope.com/t/ethanol-avgas/14707/3 "2000-03-15T02:01:00Z")
> [@](#): > > Other countries have even higher gas taxes than the US does. Very few bother to stop using gas. True, but other countries seem to have better public transportation than we do. Yes, engines have to be modified; but the $500 figure quoted is for _aircraft_ engines, which are more expensive than car engines. Note that the modification doesn’t preclude the use of regular avgas. If engines were modified or constructed to use alternative fuels at the factory, then synthetic gas would be an option, not a necessity. Let’s say the conversion _would_ cost $500. Assume the fuel is 50 cents less per gallon, and your car has a 20 gallon tank. That’s a saving of $10 per tankful. The conversion would be paid for after 50 tanks. Since I fill up about twice a week (I have a long commute), that would take about 6 months. Also, the article claims an increase in horsepower. I think a lot of people would opt for the conversion.