I can't remember if it was something I saw on tv or read on the internet, but it said the diesel engines in semi trucks can last 450,000 to 500,000 miles before they need to be rebuilt. If this is true, is it the same with all diesels like a duramax?

 

On average yes..

 

I'm certainly no expert, but as I understand it, yes. I heard that it has something to do with the fact the diesel fuel is not as "dry" as gasoline. Meaning there is more lubrication on the pistons, etc.......... Have a friend who has like 300000+ miles on his diesel suburban, and it's still chugging along. I'm jealous honestly, lol.

Josh

 

Honestly, it's impossible to say since usually something else breaks on them. The modern lsx based engines will easily last 300,000 miles with proper maintenance. There have been a few I've seen in excess of 500,000.

 

I think it's the fact that most gas vehicles are used for local personal use and are parked or wrecked long before the engine is wore on them. By the time they hit high miles they are already 5+ years old. While there are a LOT of diesels used for cross country towing or long distance work that have thousands of miles put on them every month. Within the first year can see 100k+ miles on them making them seemingly last longer.

There's plenty of high mileage clunkers out there that don't have a spot for 100k miles that are still running strong. They just look like ****.

 

Like RandomhHero said it has to do with proper maintance. Alot of owner/operator truck drivers can almost always see 800K+ miles before rebuild. With the duramax/cummins/powerstroke diesels it is not out of reach for them to see 300K+ from them with proper maintance.

 

It all boils down to maintainence.

I have owned 3 4.3L vortecs and non-vortecs that have exceeded 300,000 miles. I have owned one 4.3L exceed 450,000 Miles. I have had a 305 TBI exceed 400,000 miles. My brother has a 350 TBI exceed 500,000. His is still running and he still owns it. Mine were still running when I sold them. The newer motors will do just as well, just haven't seen them personally.

If you google, you will find a documented 350 TBI truck that went a million miles on the original motor.

I have seen diesel come apart at 45K, and I have also seen them continue running strong well past 600,000 miles. My diesel currently has either 220K or 320K, the previous owner bought it new and lost track of how many times it turned over. It still runs as good as new, it was very well maintained. It is on its third tranny, and I recently had to cut off the factory original mufflers, they finally clogged.

 

Good friend of mine that is leased on to a local trucking company pulls our rigs for us has 1,500,000+ miles on his peterbuilt. He has owned it since it was new and has only had to replace 1 rear end under it from a factory defect, and replaced the clutch once when it rolled over 1 million miles.

But he takes very good care of it and babys it. he had the best mpg out of all the trucks owned or leased from the company haha.


my 6l has right at 100k miles on it and is starting to get alot of Blowby

 

My dads buddy has a 99 silverado with a 4.8, this time last year he had over 850,000 kms on it, probably getting close to 900,000 now, which is probably around the 600,000 mile mark

 

Technically a diesel should last longer. However, good luck keeping any new diesel out of the shop regardless of the maker. If you don't use it for work and I mean heavy work then you would be better off with a gas engine they last just as long and you don't have to sell your soul in order to afford a repair once it is out of warranty. IF you mod your diesel good luck getting them to take care of stuff under warranty without a hassle. Even though by law it is on them to prove the performance parts are the cause of the failure. This has been my experience as a dealer tech.