My oil burning heart beat appreciably slower last night as I read through Car and Driver's February article entitled "Long Rangers." The test of four gas/electric hybrid vehicles, the Chevrolet Malibu Hybrid, Toyota Camry Hybrid, Nissan Altima Hybrid, and Ford Fusion Hybrid, included a sidebar entitled "Hybrid Vs. Diesel," in which they concluded that the future of the diesel car in the U.S. is "between dim and dubious."
2010 Ford FusionEnlarge Photo
Sniffle. Yet I must conclude that their deduction is mostly sound, and they have a good point. Still, in a comparison of their long-term Jetta TDI, they earned overall mpg that beat all of the hybrids in their four-car test, even compared to the now class-leading 2010 Ford Fusion hybrid that netted 34 mpg overall in their 300-mile test run. Their Jetta TDI has averaged 37.3 mpg in the over 11,000 miles they've accrued thus far, and guaranteed those miles have seen plenty of full throttle driving and liberal use of full boost from its turbocharger. A cross-country tour by mileage-busting Australian couple John and Helen Taylor netted 58 mpg from a stock VW Jetta TDI, and that was earned while staying within 5 mph of the posted limit, not put-putting at 10mph or anything ridiculous.
So what gives? Well, duh, the higher cost of diesel. Doing the math of diesel, which costs anywhere from about $0.80 to $1.00 more than regular unleaded at the moment, C/D found that operating the Jetta TDI with their drivers at the helm calculates out to 8.1 cents per mile for the Jetta TDI, well above the 5.6 cents per mile for both the Altima Hybrid and Camry Hybrid they piloted.
2009 Nissan Altima HybridEnlarge Photo
As it stands, with today's gas vs. diesel prices at the pump, these particular hybrids have a clear economy advantage over even the very frugal Volkswagen Jetta TDI. But - and this is a big but - do we all really expect the national average for regular gasoline (according to the Energy Information Administration) to remain at $1.78 (figure as of 1/12/09)? Wild fluctuations like we saw last summer could quickly diminish the amazingly low cents-per-mile figure of the gas/electric hybrids. Then again, if gas goes up, diesel will likely go even higher, so maybe my point is moot. Yet again, worldwide industry, expansion, and building, all of which rely on diesel fuel for industrial machinery, are down significantly, perhaps narrowing and ultimately eliminating diesel's premium over gasoline. Could the worldwide recession result in diesel prices at the pump coming down to, say, the level of premium gasoline or less? Ye economists at large, let me know if I'm dreaming or making sense.
2009 BMW 335dEnlarge Photo
I take issue with C/D's pat conclusion based on a rather narrow look at the mid-size, low-mid priced hybrid sedan category. Move up into the luxury and luxury SUV realm, and I think the case for diesel suddenly becomes much more compelling. Most high-compression gasoline engines in luxury cars (Mercedes-Benz E350, BMW 335i) require premium fuel to avoid pre-detonation (pinging). The higher cost of premium fuel narrows gasoline's price advantage over diesel. Moreover, the retail costs for these vehicles is much higher, making the premium for a more expensive diesel engine a smaller percentage of vehicle purchase price (in the case of the Mercedes-Benz GL SUV, the diesel model actually rings in with the lowest MSRP of the range). Finally, consider the longevity of the diesel engine, known to go well over 200,000 miles with regular maintenance; this either boosts resale value or allows an owner to enjoy many years sans car payments if he/she is the type to keep a car for 6, 8, or 10 years (admittedly, not your typical American car buyer).