Hi nw...,

Very Interesting. 4 th Gen Prius Engine ?

Hmm... Dieseline.

It sounds good but I think it will not be practical due to human behavior.

I read an article about the police cars in UK how they mix up the fuel between Diesel and gasoline (petrol) and cost a lot of tax payer money for repair.

Imagine your car has two tanks to fill up and you mix up the two? I know the nozzle size is different but people still manage to mix them up. The hassle to fill both fuel is another factor.

hmm...article is overwhelmingly optimistic. i cant help but wonder what the maintenance issues would be... filters, pumps, pressures, etc... seems like they would all have to be running perfectly or it would have to be a tip top program to be able to determine the best fuel mix on the fly.

computers are getting better and better every day... not sure that the software is keeping pace.

There is a more detail description over at GreenCarCongress:

Green Car Congress: University of Wisconsin Researchers Investigating Dual-Fuel (Gasoline and Diesel) Partially Premixed Combustion for High-Efficiency, Ultra-Low Emission Combustion; 53% Thermal Efficiency

However, it reads like a science experiment with a lot of hurdles to overcome. Two, separate fuel injection systems are used, one for gasoline and the other for diesel. Although the thermodynamic efficiency looks good, there was some discussion of emissions. This really is a lab curiosity ... just the thing to spark a whole host of pseudo-science imitators and conspiracy reports.

I remain somewhat skeptical.

Bob Wilson

Hi Bob,

The Science Daily article has comments regarding emissions. It says the gasoline burn after the low volume diesel ignition results in lower combustion temperatures and lower NOx.

They have also been mixing Propane and diesel, and it also results in improved fuel economy. It has other bonus', cleaner engine, better cold weather performance (especially starting), and more power.

But they are still diesel engines, which are "dirty" compared to a "good" gasoline engine, such as the Prius. Even when branded "clean".

<GACK>Now the OHH, HHO, HOH or HO HO OO gas generator advocates will chime in with their 'we too.' .... <AGGGHHHHH!!!!>

Bob Wilson

Well, currently they are using the propane like NOX is used in gasoline engines, to boost power. It's the -only- power boost I've seen that actually reduces emissions. So it's a pretty good deal... I guess. If you support diesel engines.

Actually, have you heard of water injection (and not the HHO mythical gas)?

Water injection can be used at high power levels to decrease the chance of detonation allowing significantly more power to be obtained from low octane fuel.

The technology has been around since WW-II where it was used on fighter planes to get extra horsepower in dog-fights.

Basically, by misting in some water, the water evaporates, cooling the air/fuel charge allowing significantly more air/fuel to be crammed in before detonation becomes a problem.

The technique is most beneficial on turbo/super charged engines where the extra detonation resistance can be used to pump up turbocharger pressures and thus bump up horsepower anywhere from 20-50%.

As a nice side effect, because water injection decreases combustion temps, it will also decrease NOx emissions, too. It will also let you run a leaner air/fuel mixture so it will also reduce fuel consumption and HC emissions (not that fuel consumption is of too much concern when the pedal is floored!).

Yup, water injection works -really- well in Edmonton. NOT! The -average- temp. here is well below freezing for almost six months.
But there are/were some die-hards that used it. The "water" was mostly alcohol.