GreenCarCongress reported on a study conducted by Argonne National Labs that tested, under controlled conditions , the efficiency and GHG emissions of various power trains.  The end result is a list showing the energy/mile for each of these options.

(Shorter bars are better)

This is the first time I’ve seen a power train comparison such as this. I’m actually very impressed with the performance of several of the technologies here, including PHEVs. I’ve been very negative on PHEVs in the past – not because there’s anything wrong with them, but I think they’re only a niche solution that addresses the needs of a rather small population. But this study is a big thumbs up for this technology.

I’m still not a convert. The reason is that while efficiency matters, it doesn’t suit everyone’s needs. Here are some thoughts:

No Plugs
Plugging in does, apparently, make some sense. I would just never do it mainly because I rent and I park on the street – like Millions of other urban dwellers. There are no plugs.

Size matters
This test focused on very small cars. In this case, a small car’s overall weight breakdown is very different using a standard power train. So it’s no surprise that the PHEV performed so much better. This should be very useful information for European drivers who prefer smaller cars. But this type of test should also be done on sedans like the Camry and Pick-up trucks like the Ford F150. That’s what Americans buy. That type of performance would be much more informational for a car buyer.

No discussion of performance
Efficiency makes no mention of performance or utility.  What kind of car could be produced with this type of performance?  A golf cart is very efficient, but couldn’t be used in regular road conditions.  The Tesla Roadster is very fast and small – two things that a family wouldn’t value in a car.  So what’s the reality behind these numbers?

What sticks out the most in this chart is that there are a lot of good alternatives for the status quo that could make a difference.  While the PHEV scored big in these tests, I think efficiency is only one variable in designing a car.  This table gives some good alternatives around which auto companies big and small can focus on creating real solutions.