It used to be easy to figure out. If your truck did lots of work or you hauled loads cross-country, you opted for a diesel or turbodiesel engine for the long-term cost savings in maintenance, better overall fuel economy, and typically cheaper prices at the pump. It all made sense. Longevity, durability, torque bias, and fuel-pricing advantages have long been diesels' obvious strengths. But that's changed now hasn't it? Today it costs a good chunk more to get the diesel, often there's an additional charge for the heavier-duty transmission, and fuel prices are climbing through the roof, with diesel pricing and taxing leading the parade. It's been quite a while since I've seen a station where diesel wasn't a good chunk more expensive than premium here in California.
Add to this the handful of smallish diesels out there and available for sale in an SUV still aren't as invisible as some would like. Sure, in the past you could tell a diesel a mile away from the rattle, shake, and earth-quaking vibration it made coming down the street, but even the much-improved diesels of today, big and small, still aren't as quiet and invisible as their gasoline counterparts. And from what I understand from John Q. (American) Consumer, that's what it's going to take. With that said, at least more people are starting to take notice, albeit a small number. Sure, a certain segment of the gearhead population gets it, but to make this work, a lot more people are going to need to get smart on the strengths and weaknesses of the gas and diesel engines.
In a recent Kelley Blue Book survey (admittedly looking at a consumer, general-interest audience), they found people still did not understand the benefits diesels offer and the fact that new technologies have made stellar advancements in smell, sound, and power. KBB found a small percentage of people were considering diesels and the reasons they gave paralleled those same reasons people didn't like diesel 20 years ago: noisy, smoky, noisy, gutless, and noisy. For those of us who know, we've come a long way, but the problem seems to be getting the message out. We can help with that. Truck guys have been on the leading edge of the diesel bandwagon for years, and now it seems some of the go-fast crowd is getting on board, pointing to a whole host of European cars sporting fun-to-drive small turbodiesels. Small cars with torque-biased oil-burner engines and manual transmissions have long been Europe's answer to $8- and $10-per-gallon fuel. But this isn't Europe and we don't have a country full of average car buyers that want small, sporty German sports cars.
Here's my guess: Even if the message gets out, there will still be hesitation. In 2010, we'll have the cleanest fuel and cleanest tailpipe emissions we've ever seen for diesel, thanks to quite a few breakthrough technologies, but the fuel will still smell funny, feel oily, and create a problem when it gets on my wife's shoes. And there's no significant green angle yet, as there is with hybrids, and that single marketing asset seems to be necessary for popular consumption. Hybrids and their current market success have changed the way car (and maybe SUV) buyers look at the playing field. Biodiesel could help if the message gets out properly, but now it just seems like an underground economy run by people who don't want others in on their cool little secret.
Diesel SUVs are likely to get the greatest penetration into the marketplace, but I'm not sure making them more complicated with extra urea fill-ups every 10K or 15K miles (like the M-B BlueTEC system) is going to make people feel any better about the tradeoffs. We're not making diesels a simple powertrain choice yet, where the negative aspects of diesels are offset or nullified, making a choice between gas or diesel imperceptible. No doubt the enthusiast light-towing crowd will get the turbodiesel SUVs first because of the low-end torque advantage that will be hugely noticeable for trailers between 2000 and 5000 pounds. Getting 400 lb-ft of torque out of a V-6 (I-6?) engine that can get 25 mpg on the highway when empty (and not much less when towing) is going wake those people up. Until then, unless the diesel hybrid sounds like a gas-powered sewing machine that drinks sweet-smelling fuel sold at every shiny gas station, I'm not too sure the midsize SUV will be the entrance point for wide acceptance of diesel powertrains. But I hope I'm wrong.