I should have worded my assertion differently. It should have read
...
"Ironically the new clean diesels are arguably much better environmentally than hybrids, particularly in SUV/SAVs."

The argument goes that in order to compare the 'greenness' of hybrids to diesels you have to include full life cycle environmental impact. For hybrids this includes the mining of the heavy metals, the manufacturing, as well as the disposal/recycling of their batteries, etc. For the diesel this includes the oil production, refining and transportation of the oil/diesel, etc.

These are not easy data to collect, or calculations to do. And the results are even more difficult to substantiate, to the degree necessary to support an advertising claim. The analysis would require quite a few large assumptions. For example which mines did the heavy metals come from. Or which oil field and what refinery was used for the diesel.

Finally, you have to actually compare products that can do the same things. In the case of SUV/SAVs for example, a key might be towing capacity, etc..

FWIW we seriously considered hybrids when looking for a replacement for our wrecked X5. But soon realized that hybrids are at their best in congested urban environments. And the new clean diesels are at their best on the open road. Since we live in the country, the vast majority of our driving is on 55-60mph 2 lane hilly roads where the diesel shines both in terms of performance and MPG. The fact that the diesel could also tow a couple of tons of road base made it a slam dunk

Funf Dreisig