Bring back the Geo Metro!

[theholycow]

Originally Posted by Jay2TheRescue

I think that its interesting that the first real crossover on the market (Pontiac Aztek) was a failure. It could have easily happened that we never got all the crossovers we see now.

I think crossovers were inevitable; CAFE pretty much guaranteed them. What I find interesting is that everything that everybody blamed for the market failure of the Aztek can be found on popular newer vehicles.

[trollbait]

My favorite feature of the Aztek is using it as a counter point to Prius fans complaining of another car copying the Prius look.

[rfruth]

I liked the slide-out cargo-area storage tray that could double as a table for "tailgate" parties or be folded out to make a wheeled cart. (didn't have a Astek)

[Charon]

Originally Posted by Draigflag

30 hp per litre? Are you seriously living in the past? Do you know how a diesel works? Are you even aware that Audi use diesel cars in the Le Mans Race series?

Proof that the US is behind? Go and spend a week in Tokyo, it's like stepping into the future.

Apparently I am completely unaware of how a diesel works. Be so kind as to educate me, that I may no longer display my ignorance. As far as visiting Tokyo, I am afraid I don't have the resources for that. Instead, I'll keep up on the news releases about Fukushima.

[Draigflag]

You just make yourself look a bit silly when you say "30 HP per litre is about all you can get" when you know for a fact that Audi have a 5.5 litre V10 Diesel with 650 HP.

Here's some info to help you look less silly in the future:

http://www.howstuffworks.com/diesel.htm

[Charon]

Originally Posted by Draigflag

You just make yourself look a bit silly when you say "30 HP per litre is about all you can get" when you know for a fact that Audi have a 5.5 litre V10 Diesel with 650 HP.

Here's some info to help you look less silly in the future:

http://www.howstuffworks.com/diesel.htm

That isn't what I said, and you can look back through the thread to verify it. Nor did I know (or care) that Audi has such an engine, if for no other reason that I don't even consider Audi if I am looking for cars.

Now, some basics for you. Naturally aspirated piston engines can be expected to make on the order of 1 ft-lb of torque per cubic inch of displacements, and that doesn't vary greatly between gasoline and diesel engines. Thus, a 1 liter (61 cubic inch) engine can be expected to make about 60 ft-lb of torque. Torque times rpm gives horsepower, and with the appropriate constants horsepower and torque are equal at about 5255 rpm. It is unusual for diesels to spin that fast, and larger units like the ones in trucks or buses usually don't get over half that. If the engine makes the expected 60 ft-lb and spins at 2700, it is making 30 bhp/liter.

The way to increased power lies in burning more fuel. That can be done by increasing the fuel burned per power stroke and thus the cylinder pressure, or increasing the number of strokes, or both. Increasing the number of strokes usually runs into mechanical limits, or in the case of a diesel a limiting factor is the time available for fuel-air mixing during injection. Increasing the amount of fuel burned requires increasing the air available for combustion, and that is where the supercharger enters the picture. Adding extra air increases cylinder pressures and temperatures, which requires an increase in engine strength and weight, while burning more fuel makes more heat and requires an increase in cooling capacity. Conventional gasoline engines quickly reach preignition limits and require higher octane fuels. Direct injection helps, and may even lead to the ability to use stratified charges, but again raises the issue of the time available for mixing.

Automotive engines are very seldom tested for any serious period of time, such as an hour under full load. None would pass unless cooled by something other that their own cooling systems. When auto engines are converted for use in such as boats or experimental aircraft, they usually have to be derated to about 30 to 40% of their advertised ratings. Decades ago when Ferdinand Porsche designed the original VW, he knew that his customers would run the car wide open. So, he designed the intake and exhaust systems to be restrictive so the engine would survive. That's why the old Bugs responded so well to intake and exhaust modification.

Feel free to do you own research and to refute any of my points, but don't just use motojournalists and advertising for your information sources.

[Draigflag]

So if you know how a diesel engine works, and have read and seen the benefits, be it performance, economy, emissions etc etc, then why all the diesel bashing and negativity towards them? Americans are long overdue an attitude change towards diesel, I know the US government is obsessed with N0x emissions, but the other 95% of the World are investing all thier environmental concern on C02, and an easy way to dothat is to offer more diesel which as you've said, use up to (in some cases) ten times less fuel, and using less fuel also creates less C02. Even though the US is only 5% of the World's population, they are still accountable for 25% of the entire C02.

[Charon]

Perhaps you can quote me bashing diesels. I have tried to present actual facts. As far as I can recall my diesel "bashing" has been primarily related to cold starting. Diesels do have benefits, mainly in fuel economy. But they also have penalties in power-to-weight and usually power-to-displacement. I also know of people who find the time required for the "wait to start" light to go out to be very annoying.

Make your own comparisons, but in general for the same power a diesel will weigh more and burn less fuel. For the same weight a diesel will produce less power. For the same displacement, absent supercharging (including turbocharging) the diesel will produce less power. There are reasons why diesels are not used for motorcycles, outboards, or airplanes, and reasons why they ARE used in road vehicles, larger boats including ships, construction equipment, and other uses where their weight is not a drawback. In fact, for railroad locomotives, their weight is a positive because tractive effort is higher with more weight on drive wheels.

[Jay2TheRescue]

The "Wait to start" light is quickly disappearing. The Audi TDI's don't have one. I also used to drive ambulances, and the 99 International DT4700 we had didn't have one either. When you boost the engine compression in a diesel, you often don't need glowplugs. Just crank & start.

[Charon]

Our school's 2011 International bus still has a "wait to start" light, and that is the newest diesel I have driven. In its case, I think it uses some sort of resistive intake manifold heater instead of glow plugs. There are at least a couple of warning labels cautioning against the use of ether or other starting aids, saying something about risks of fire or explosion. There is also mention that if the weather or the engine is warm the "wait to start" light may not come on.