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- Much more expensive to build (29 or 30:1 compression ratio means a stronger and heavier engine is required).

You're a bit off.. the VW TDI is about 18.5-19.5:1.

- Much less power than an equivalent gasoline engine

Deceptive.. the 1.9L TDI has only 100hp, but it has 177 lb-ft of torque, which makes up for the lack of RPM. Compare this to the 2.0L gas engine which has 115hp, but only 122 lb-ft of torque

- Extremely difficult to start in very low temperatures

Not at all, the fuel system in the VW TDI is heated to prevent problems with gelling. Also, Winterized fuel is used in all of the northern states.

- Fuel non-volitile at very, very low temperatures

again, pre-heating of fuel is done to eliminate this problem.

- Requires a very large oil sump due to combustion contaminants

I guess I have no idea about this one.

- Noiser than gasoline engines

I havn't taken a SPL meter to it, but my friend's TDI is signifigantly quieter than my 2.0L gas. When I hear a TDI drive by, the only thing I can hear is the turbo spooling.

- "Dirtier" than gasoline engines (not only in particulate pollution, they just get physically very dirty)

Yep.. this is the main reason why Diesel cars don't exist here, because of the sulfur content, some emission control devices must be left off (damaged by sulfur). The emissions numbers for Diesel are really bad per same ammount of gas.. After ULSD is out, I'm really looking forward to seeing the better emissions control devices.

They have a couple of nice advantages:

- Much more efficient than gasoline engines (due to the higher comresson ratio. There is an upper limit on Rc for gas engines because the fuel detonates. The compression ratio determines a displacement engine's efficiency.)

Yep.. that and y ou don't have to feed a signifigant portion of your energy back into producing sparc.

- Tend to last much longer than gasoline engines because they are more heavily built and run at lower RPMS and lower temperatures
- The energy density of the fuel, per unit volume, is higher for diesel (more range on your fuel tank)

ULSD and BioDiesel addatives will make this even better. (Bio is a better lubricant, and a solovent)

- Generally huge torque at low engine speed, which is great for pulling vehicles

The 1.9L VW TDI has a tow rating of 2000 pounds.