I know a way to get one hundred miles to a gallon on a Hemi. and it's no April fools Day joke. Go to this web site.
www.lpga.couk/lpga.htm Now I know this works. A lot of City buses are now using this method. an our government is paying for it. and in Canada if you have it put on your truck the pay you back $2,000 . The only problem is who has it here in the US. And why doesn't GB want us to use it. ? What you do is after you start your engine on gasoline ,when you get upp to speed ,you switch over to propane ,It's that simple. 300,000 miles on a set of plugs. oil changes at 50,000 miles.The engine will almost last for ever. I used to work for a major oil refiner We had a car that ran from Ny City to California on a tank of gasoline It was a four cyclinder engine with this set up. If anyone finds out the place that sells it here in the US please post so we all can get in on the savings. Good Luck.