TDI vs. Gas Powered

If you want a diesel then by all means get a diesel. But the perception of diesel as a clean fuel is a misperception. The reason diesels were exempted from emissions testing is not because they ran clean, but rather because they could not be mad eto run as clean as gas engines…well, that and the political lobbying by the national truckers association.

Diesels run with high conpression ratios and high temperatures. The heat energy that initiates combustion comes from the heat of the compression rather than a spark plug. These things make reduction of emissions constituants, especially oxides of nitrogen (NOx), extremely difficult, particularly during warmup. While fuel metering has come a long way toward reducing unburned hydrocarbons and carbon monoxide, NOx still cannot meet the standards applied to gas vehicles.

But what about the increased refining standards? We now have a choice between low Sulfur diesel and ultra low Sulfur diesel, and eventually, the ULSD will be the only diesel fuel available. This stuff burns a lot cleaner than the diesel fuel sold in the 1990s before the refining standards were increased.

This is a big improvement, but does not address the NOx problem.

As I mentioned, modern fuel deliver technology has, I recognize, gone a long way toward reducong the HC and CO outputs.

I would not say mountain is all wrong, but I will say that he should review the most current clean diesel technologies. I don’t believe we had any such cars before the current model year (In North America) but these cars are considerably cleaner than prior models and were kept out of North America, in part, due to the lack of ULSD (Ultra Low Sulfur Diesel).

It remains difficult to compare the pollution from the newest and best gasoline and diesel car engines. They pollute in different ways so it is comparing apples and oranges.

The flip side to the ‘clean’ diesels is the added equipment needed to do this. While the basic machine remains sturdy, the added pollution control systems make these modern diesels not much more reliable than a gas engine.

Modern diesel engines have come a long way. Today’s Blue Tec diesel engines are clean as are modern gasoline engines. Both could be cleaner.

It is not possible to compare them as each is cleaner or dirtier in different ways. I don’t believe there were any Blue Tec diesels in the US prior to the current year models. This technology is also on new VW models.

http://en.wikipedia.org/wiki/BlueTec

Special TDI oil is expensive compared to gas engine oil, 7 to 8 bucks a quart and more at the dealer.
Fuel filters are 25 to 30 bucks and more at the dealer; must be changed every 20K miles.
Diesel fuel for the past several years has been more and sometimes considerably more expensive than gasoline, only recently became more equal and that will change again.
Turbo life statement is from watching TDIClub.com and VWVortex.com as is coking up statement.

Diesel fuel over the last fifty years has been cheaper than gas except for the last two years .
VW spec 502 oil which is what the gas engine needs is the same price .
Turbo life is dependant on using the correct oil .

Special TDI oil is expensive compared to gas engine oil, 7 to 8 bucks a quart and more at the dealer.

Not in my experience. Yes oil is more expensive, but unless you are buying it from the dealer, there is no reason to pay that much for it. Same goes for the filters. They are both more expensive than for a gasoline car, but not enough to worry about.

I had a 2002 VW Beetle diesel that I loved, but my wife didn’t. Some crap about it being too small for the family. I miss it. Unfortunately, she won the argument almost 2 years ago, when VW suspended diesels b/c Congress was being as unreasonable as my wife.
I have driven the Mercedes diesel, and have not driven the BMW. Most European cars (in Europe) are diesel because of the longevity & mileage.
Anyway, in 2002 I had no problem ever finding diesel. The gas stations across the street from work & home had it, as many did in between. I once coaxed 50 MPG (all highway) out of it on a trip from Chicago to Cape Cod.