We got into a gearhead drinking discussion over the weekend concerning why a diesel is significantly more efficient than a gasoline engine. The non-gearhead in the discussion claimed diesel fuel has more energy than gasoline. I claim it's the more efficient high compression design of the diesel engine that extracts the energy from the slower burning diesel fuel.

Can anyone out there settle this before it becomes a gunfight????

Dave

Well, without getting into the highly technical analysis of the two types of fuels, I CAN say my Mercedes sneezle will get me to work & back far more times between fill-ups than any of me gasoline powered vehicles. Sounds more efficient to me. I will say, thi...there ain't ANY Top Fuel cars runnin Sneezle oil for fuel...does that mean it has less energy than gas???

If those are the best explanations I can get, there's gonna be a gunfight!!!!!!!!

You can make the data fit either argument you want to make. If the argument is really over efficiency then all one has to do is take two like vehicles with the same engine displacement , same gearing, same test weight, and same size fuel tank. The only difference is one burns gas and the other burns diesel. If you drive them exactly the same over the same terrain until the first one runs out of fuel, then theorectically the one still running is more efficient. You can debate all day whether it's the engine or the fuel, but the one still running is the most efficient. It makes the most use of the fuel load. After all they are both internal combusion engines.

Scott

There is no question that the diesel is more efficient than the gasoline powered mill, the question is WHY????

And Ron.... This IS Tennessee where everyone packs BOTH a gun and a knife....

Dave

The Audi R10 race car that competes in the LMP1 category in the American LeMans Series is a 650HP V-12 diesel--and it's got an enviable record of wins in the Series over gasoline-powered competitors (although an LMP2 class Porsche won at the latest ALMS race in Utah). That doesn't answer whether they're more fuel-efficient than 'conventional' (gas) engines; just that they've proven that a diesel can race--and win--in a world-class motorsports series.

Speaking of which...if anyone else here is a fan of the factory Corvette Racing team, you know just how dominant our own favorite marque has been in the ALMS. In fact, the entire competition in the GT1 category has left the field, having been routinely trounced by the mighty yellow C6 twins. Even the vaunted Aston Martin factory team, which did manage to win a few races after the Vettes were penalized with added weight and intake restrictions, hasn't shown up for most of this season.

So I for one would like to salute Doug Fehan and the Corvette Racing team for proving yet again just how great Corvettes are on the track. They've sent everyone from Ferrari to Saleen to Maserati, Lamborghini and the odd Viper or two home. And with the 24 hour race at LeMans coming up, they promise to put in another great performance this year.

Gasoline has a better burning rate than other fuels. It also allows the car to start quicker in cold weather in addition to providing smoother acceleration and more power. Sneezel fuel, on the hand, is a lower quality fuel burned by sneezel combustion engines. These engines are ignited by the heat of compression rather than spark plugs and generally run more efficiently, last longer, and get significantly better fuel mileage than gasoline engines. However, cars that use sneezel fuel tend to be noisier, slower, and harder to start in cold weather.
Sooo...if you take into consideration the fact that sneezel fuel is basically waste oil, yet it burns more efficiently in a compression-fired engine(ie: uses more of the available energy per gram/gallon) than gasoline, then the ONLY conclusion you can come to is that the sneezel engine is, by design, a more fuel/energy efficient engine.

I am not an engineer, so I couldn't say WHY it is that way, just that it is.

Okay, Here I go.