Currently, diesel-powered cars from MB and VW can't be sold in CA and four other US States because they emit too much NOx particulates. These emissions would be drastically lowered by low sulphur diesel, which contains about 300 times less sulphur than the diesel currently being sold in the US now.

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1999 Mercedes-Benz S600, 103K miles - garage queen
1988 Mercedes-Benz 560SEL, 89K miles - daily driver
2007 Hyundai Sonata Limited, 31K - daily driver