Originally Posted By: TiredTrucker
Makes keeping an eye on the new EBDI engines being tested by GM in their 3500HD pickups worth it. These engines, 3.2L in size, are kicking out the same hp and torque as a 6.6L duramax diesel, and getting better mpg to boot! And all on E85. Ricardo, the UK engine designer, is working with GM on this engine design. Easy look up if anyone wants to read about it. Even a few you tube videos on the engine by the lead engineer at Ricardo.
And if they run the same technology on gas, they'll get even better mileage to boot...
You simply cannot get away from chemistry and stoichiometry.
Look at the following chart...it might take a little math to work through the ideas, as it's in S.I. units as opposed to gut feel and feel good...rubbish pic, but the source is "INternal Combusion Engine Fundimentals" by J.B. Heywood, you might be able to find a scan on Google Books, or pull up his references from the bottom of the page.
One of the columns gives the available energy at stoichiometric mixture...alcohols lose to gas/diesel...then throw in Air/Fuel ratios and fuel density...alcohols lose to gas/diesel.
Ricardo Institute (and I'm not sure if you understand their origin, Sir Harry is one of my heros) are great, they will make a great solution...but simple chemistry says that if they get the thermal efficiency correct, and a power output, the same technology will give more miles on a gallon of gas...and we get back to ethanol standing meritoriuos only on cost per mile.
* For those interested, you can take the figures for either of the alky's, and working out from the latent heat of vaporisation (only available with carb or port injection), energy at stoichiometry, and Octane ratings why alky cars can make more power than gas...at double the fuel consumption (methanol).