Are diesels still more reliable - and longer-lasting - than gas engines?
Well, diesel engines aren't really inherently longer-lasting than gas engines. Our experience with diesels in this country is generally limited to Volkswagen and Mercedes diesel engines, both of which were built to last until the End of the World. It wasn't uncommon to see a half-million miles from those engines, but it also wasn't unheard of to see a half-million miles from a contemporary gasoline-powered Merc or VW, either.
While it's true that diesels still don't have spark plugs, they have most of the other expensive stuff on them that their gas-powered siblings do. We expect them to be just as reliable as gas engines - which is to say very.
Why would I want a diesel instead of a hybrid?
That's a really simple question with a really simple answer: Because if you want to save money, you don't want a hybrid. Studies have shown that people are buying hybrid cars to send a message - not to save money. This is a good thing, because while they do save a little bit of fuel, they don't save money.
Many hybrids will never save enough fuel to cover their initial cost premium, not to mention that the battery pack will some day need to be replaced at a huge cost.
Diesel cars also tend to have far better resale values than their gas-powered equivalents. For example, a 50,000-mile 2004 Volkswagen Jetta GL with a 115-hp gas engine is worth $8875 at auction. That same car with the same mileage, but a 90-hp diesel engine is worth $13,950. That's $5075 - or 57% more. (The Touareg V-10 TDI's resale value is even more impressive - see the chart below.)
It's the same story for heavy-duty diesel trucks. A recent marketing study showed that after four and a half years of ownership, the average diesel truck is worth $4700 more than its gas equivalent, and has saved the owner more than $4200 in fuel. That $8900 difference more than offsets the truck's astronomical initial purchase premium (an average of $6600).
To boot, diesels get their best fuel economy under the types of conditions that most Americans drive - on the open road. Automobile Magazine editor-in-chief Gavin Conway recently got nearly 40 mpg driving across Florida in a Mercedes E-Class diesel (a car that gives a Volkswagen GTI a run for its money in a stoplight drag). Hybrid systems offer almost no benefit on the highway, so unless you're sitting in traffic, you're not saving anything.
What about E85?
Do yourself a big favor and forget about E85. Much like Paris Hilton's career, it's made of a lot of hype and not a lot of substance.
You'd need 1.7 gallons of E85 to equal the energy contained in a gallon of diesel fuel. It takes something like seven percent more energy to create a gallon of ethanol than that gallon even contains. And to add insult to injury, if it weren't for the federal and state tax breaks on E85, it would cost one dollar per gallon more than gasoline. (And that gallon of gasoline would contain 11.5% more energy, anyway.)
The E85 push benefits the car companies, not consumers. It gives the manufacturers a fuel economy CAFE credit for reducing gasoline consumption, even if the car is never run on E85. Which, of course, most never are. When was the last time you filled up with E85?