Diesel Power Vs. Hybrid Synergy Drive: A Tie? Not Really.

There’s been a bit of Interweb buzz lately about a comparison done by London’s Sunday Times between a Toyota Prius and a diesel-powered BMW 5-Series sedan.
www.fivestartoyota.com driven from London to Geneva, covering a total of about 545 miles - doubtless a fairly interesting jaunt. About 100 of those miles were urban miles where the Prius could operate in an optimal environment, and about 445 of them were suburban miles where the BMW would have the advantage.
Over this distance the Prius averaged 48.1 mpg while the BMW diesel averaged 50.3 mpg.
We hear you Prius skeptics saying, "Ahah!" Yes, the Bimmer bested the Prius by a whole 2.2 mpg.
But that’s not all there is to the story. The Times story, which you can see by clicking here, listed not only the cost of fuel for both cars, but the cost of the vehicles themselves, including their respective road-tax bills. And it is when pondering these numbers that we gain critical perspective.
In traveling from London to Geneva, the BMW’s diesel fuel bill was ₤54.19, while the bill for the Prius’s Unleaded gas was ₤54.64. At today’s rate of exchange between the dollar and the pound of about two to one, that’s $108 spent on diesel fuel and $109 spent on Unleaded.
So, OK, a difference of a buck? Call that a draw.
But this is a tie that’s easy to break. List price for that BMW 5-Series diesel in Britain is ₤27,190, and that doesn’t include a road tax of ₤115.
List in Britain for the Prius is ₤20,677. Road tax for the Prius is just ₤15.
Beyond costs, the Times failed to address the vastly superior performance of the Prius on emissions other than CO2 – you know, those things like particulates and oxides of nitrogen that cause human health issues. Here the Prius shines, with a quarter the particulate level and less than a 10th the NOx of the BMW. We believe that these lower levels are important.
So maybe we’re missing something here, but it looks to us as though, when all costs are considered, the Prius is markedly less expensive to own and operate, about even on CO2 and fuel costs, and markedly cleaner on other tailpipe emissions. We can’t really say that we’re surprised.