(Pro-diesel blah blah blah)
My husband and I own a landscaping business. We have just shy of thirty vehicles and have had our fair share of diesel motors over the years in our trucks, which have ranged from Isuzu cab-over trucks to Sprinter vans to Chevrolet, Ford, and Dodge pickups. The value never adds up for them which is why we're all-gasoline and planning to stay that way.
Diesel motors have a lot of disadvantages... First of all, to provide sufficient power and torque, they generally require turbocharging. Turbochargers go bad and have to be replaced. Most gas engines don't have them.
With those turbos come exhaust leaks, oil leaks, etc. Turbos are great, but don't hold up in the long-haul, not in a small car/pickup application.
They may not require spark plugs, but to mitigate difficulty starting most of the smaller diesels require GLOW plugs...expensive replacement item that the car has a tough time starting without...not present on a gas motor. If you get an oil leak and the glow plugs get wet with oil, prepare for a heck of a bill at the mechanic fixing everything.
The fuel doesn't work well in cold climates...it freezes well before gasoline and requires expensive additives and/or tank heaters to work in cold weather...again, gas doesn't require that.
Mercedes diesel motors, like any Mercedes product, will be durable if you continue to sink money into them over the years in maintenance. I would never own a Mercedes that wasn't under warranty. I've had a half-dozen Mercedes-Benz products in my life, including a California-legal 1999 E300 Turbo diesel several years back and can tell you that I will never make the mistake of owning one, diesel or gas, that wasn't under warranty. My one diesel car I bought because it was new and got great fuel economy. In the two years I had it, I spent more time in a loaner car than in my Mercedes. Total bill from the dealership to Mercedes for warranty work? $19,000 in two years. The mechanic specifically told my husband and I that "they don't build them like they used to." This "durability" that people speak of when talking about Mercedes ended in the early 1980's. They're a needlessly complex vehicle that is a genuine pleasure to drive and own as long as you don't have to pay for repairs. I currently have a GL550 and consider myself a devoted Mercedes owner. I primarily drive them for the safety of my children. Don't judge me for being in touch with what owning a Mercedes is all about. It's about money, and how much you're going to pump into the dealership or your trusted mechanic. I trade mine in the day they're out of warranty and have done so for years.
All this talk has me a little nostalgic. The best car I ever had was my 1994 E500. That was just a wonderful car to have and was my second Mercedes-Benz product. I do wish I had kept that one and would happily pay the thousands in repair bills to have it around, perhaps to give to my son. C'est la vie but I do miss it.
Most of the diesel "longevity" that people talk about involves heavy trucks with sleeved engines that can be overhauled in the vehicle. I've never seen a light-duty diesel that wasn't a throwaway block or a non-sleeved design. They're not better built than a gasoline engine, really. They're built tougher to deal with the intense vibration and heat from the the engine and turbo but they're not a fundamentally different design from a gas engine other than igniting by compression rather than spart.
I'm not denying the benefits in heavy trucks....I'm saying small car/pickup diesels are just a waste of money and, no matter what anyone says, they cost more to maintain and own. The repair bills are the proof.
