I posted this response last month to a very long thread and never got a response so I wanted to through it out again. The discussion was why diesel last longer than gasser. Many said they do not. Below is my reply to them. I am interested in hearing other thoughts.

Well I wasted time looking on the internet for torque info when I had it in my 124 Service Manual. Shows you how smart I am. Here is the HP/rpm Torque lb-ft/rpm for the engines listed.
Gas
130.940 6cyl 158/5800 162/4600 M.Y. 1990
103.983 6cyl 177/5700 188/4400
119.975 8cyl 268/5700 295/3900
119.974 8cyl 322/5700 354/3900
104.980 6cyl 217/6400 195/4600 4 valves per cylinder

Diesel
602.962 5cyl 120/4600 164/2400
603.960 6cyl 143/4600 195/2400

In most gas engines the hp is higher than the torque but you can see how much I know about Mercedes gassers. In all except one the torque is higher than hp. But back to my earlier statement about torque in most gassers, they do not reach max torque until significantly higher rpm than the deisels, as in the case above. You are never going to use the max gas torque numbers from above unless you are going somewhere fast. The only 6cyl from above that has the torque of my 603.960 is the suped-up 104.980 but notice that it does not reach the max torque until 4600 rpm. What that means is the 104.980 is going to get there a hell of alot quicker than I would but I could drive around town and on the highway at normal speeds at significantly lower rpm. That means less engine wear. This is one of the reasons a well built diesel should outlast a well built gas engine.

Reason number 2) Diesel is a light oil and gas is a solvent. Until we get DI gas engines, the intake valves are exposed to a solvent. This is why diesel intake valves should far outlast gas valves. The same case can be made for the cylinder walls as well. Onto the exhaust valves, yes that black smoke coming out of diesels does still have some lubication properties until at least we get low sulfer fuel.

Reason number 3) Diesel engines are built heaver. Sure you need it with a compression ratio of 22 to 1, but the engine will handle other stresses better. We are talking well built engines here. I know everyone has a crappy diesel story but this goes the same as gas engines as well.

There may be other reasons but I think these are the big three.