Seriously. It doesn't exist. It's an oxymoron created by the people who make diesel engines and sell diesel fuel. New diesel may be cleaner than older diesel formulations and the new engines may be more efficient but it's still dirty. Oh, and VW lied and cheated the system to make their "clean diesel" vehicles. Why? Well, it was easier than marketing "filthy, noxious diesel deals" and anyway, all those sings were already printed...
From Car Talk's Ray Magliozzi:
Oh, this should be fun.Car Talk: Diesel versus hybrid in efficiency test
Dear Car Talk:I own a 2006 VW Jetta diesel. It has just over 60,000 miles on it, and everything is working just fine. As I live in a rural area with few stoplights, my mileage averages 50 mpg. Since diesel isn't the cleanest fuel, I am wondering if a Prius hybrid would be as efficient as the VW, but less polluting. I also am interested in knowing under what driving conditions the Prius is most efficient - city versus country. Thanks. - Barbara
Ray:The Prius will be cleaner than a diesel, Barbara. At the moment, it's about 40 times cleaner than a VW diesel. And it's likely to be just as efficient.
Even factoring in the end-of-life issue, since the hybrid batteries are recycled by Toyota, I think it's fair to say the Prius is the cleaner choice.
While hybrids tend to be most efficient in stop-and-go driving, where their battery power is a huge advantage over a constantly idling (and polluting) internal-combustion engine, hybrids are not bad in highway driving, either.
The redesigned 2016 Prius is supposed to get 54 mpg in the city and 50 mpg on the highway. You probably can live with that, right?
On the other hand, we have to give VW credit for making a car that handles better than the Prius and probably is more comfortable, more solid-feeling and probably better in the snow.
So those are factors to consider, too. And if VW ever comes clean and figures out how to fix these nitrous-belchers, they'd be worth considering again. We'll see.We will see. And I'll predict it right now. VW isn't magic. There isn't a way to make clean diesel. It's a scam, a lie, a marketing strategy that got called out for what it is, fraud.