And your reference to this would be...???????????????????????????? Seriously. I'd like to read about this reference. I'll wait...
No problem on average consumers using E85 get 26.5% worst mpg then when using gasoline. The second order effect is it cost them on average 22.9 cents per mile with E85 versus 18.7 cents per mile with gasoline.
By relating the observed fuel economy to CO2 emission figures found in the EPA's Green Vehicle Guide it is determined that a 500 mile gasoline round trip produced 706.5 pounds of carbon dioxide. On E85, the CO2 emissions come to 703.1 pounds. The difference comes out in E85's favor, but only by a scant 0.5 percent. Call it a tie. This is certainly not the reduction in greenhouse gas emissions we had been led to expect.
Recent concerns have surfaced about the efficiency of ethanol production. Some critics have actually said that it is a "negative energy source," meaning that more energy is required to produce ethanol than it delivers as a fuel. Further doubts have surfaced about the true environmental benefits of ethanol and E85. And some critics have said that as farmers switch from growing corn for food production to growing it for ethanol, it could produce food shortages. Higher corn prices have already been reported.
As for propane now. The cost for the head damage caused by a dry gas stripping the lubrication off the intake valves and cylinder walls (the valve problem is eliminated with the injector system but the cylinder issue remains), as well as the need to have the propane system cleaned and recalibrated every 3 months or so for optimal performance (roughly $45 plus a new vaporizer diaphragm every 9-12 months.)
There is more to propane then just cost. There is a minimum of 20% performance degradation because of the thermal potential differentiation.
All those variables need to be included
The cost benefit does not outweign the cost "savings" and hassle factor because, at the end of the day, there are none.