OK - went and looked up the study.
One - done by a marketing firm who worked for GM. No evidence that it was a peer reviewed LCA study meeting ISO LCA standards.
Two - a number of assumptions are questionable. For example one assumption is that hybrids will last half the lifespan of hummers. Questionable at the very least. Hybrids -especially Honda's hybrids get very high reliablity ratings. The hummer gets very low reliability ratings. Also one of the ways to get these figures is that R&D energy costs are being counted very heavily. Now the hummer has been around since at least the 80's and maybe the 70's. So its R&D costs are distributed over a lot more cars than Hybrids. This is like a really ersatz levelized cost techique. It is like taking a power plant that has been running only a year, and distributing its capital costs over the power it has produced so far and comparing that to the similarly levelized capital costs for a power plant that has been running for 20 years. In other words to get these results Spinella was expensing rather than amortizing capital costs. He admiteed in an interview that if the study was done three years from now the resulst would have been different - in part because hybrids are improving, but mainly because there would be so many more hybrids to distribute R&D among. Which, of course, is why it has been standard accounting for a long time to amortize not expense capital costs.