Experiences with a Cummins X15 good/bad?

How many miles u put on them til ya trade it out? All my experiences with isx has been 400k+ miles

 

We have 5 X15's in our fleet with a combined total miles of of 1 million miles.

Highest one was 550, miles and we had to over haul it. ( we got the truck at 402,000 miles so don't know how it was treated )

Other than that every single truck has been awesome and the only issue we have had are small things with the body of the truck, nothing with the engines.

We also service the trucks with synthetic oil every 450 hours ( regardless of miles )

Always do all fuel filters / air filters and obv oil filters.

 

A couple I’ve sold at 400k and I have one currently right at 500k that I missed the gravy train time frame on selling. I feel very confident in it though but like I mentioned, it’s been very well cared for. I’d be extremely disappointed if it didn’t go another 150k miles atleast. Truck wise it’s in great shape so maybe I’ll just keep running it as a test to see how far trucks can go with our maintenance programs.

 

I know the isx was junk and was terrible for blowing out the block. But I haven’t heard as much negativity about the X15 which replaced the isx.
However I did go with Detroit over Cummins due to past isx experiences and couldn’t find enough people at the time that had enough miles on an x15 to get a good comparison.

 

I drove an X15 for years in an International LT. Thing was a horse and was very reliable. The only problem I had was it threw a fuel pump going down a steep hill in the middle of the desert at like 375000 miles and after paying over 3000 for someone to come out at 1am and replace it for us, it blew the fuel line attached to the new pump 100 miles later.

But other than that, the most reliable engine I've ever been behind so far was the X15. It was a horse, it would outpull anything. 475hp and 1950ftlbs of torque. If I'd stomp the gas in first gear I could bend stuff that wasn't supposed to be bent. I had to be careful.

 

X-15 deleted with 600hp has been really good to me with just over 500K on it. Replaced a turbo and that’s about it.
Don’t use anything special for oil. Rotella T4 every 12,000 miles with all filters changed at that time. Ive been very happy with mine.
I’ve had a platinum rebuild kit sitting in my shop just waiting for it to go boom. So far it looks like I pulled the trigger on that way too early.

 

when I worked on (Air Force) jet engines they always had a few engines "flying" with more hours than the rest. They called them "pacers" and just as you mentioned, it was to determine whether or not our scheduled maintenance intervals were appropriate. Problem is, these engines were in F-16's which are single engine (aka lawn darts). I always wondered if they made the pilots that would get into trouble do some time in the "pacers"

 

Any engine can break down. Personally I like isx15 I have in my truck. Plenty of power and it gets decent mpg vs classic with cat in it. They can brag all they want but I save enough money in fuel savings enough for inframe.

 

Either option id say your taking a 50/50 gamble as far as the engine goes. I know guys who have had good and bad luck with both. Having said that I would steer clear of anything with an eaton automated transmission. They can bleed your bank account dry in no time.

 

My 20 Cascadia has an X15. I bought it new and have replaced most of the aftertreatment parts, a water pump, and an alternator. That's it, in 4 years. Sitting at 713k.
I change the oil every 25k, always 10w30 delvac.
I can guarantee all the "boat anchor" posts are guys that had "fleet maintained" equipment, which is every 50k for oil changes. Never, ever buy anything that has "fleet" in the description. They take perfectly good engines and make them garbage.
No experience with Paccar, and no desire to find out. Detroit has their $20,000 one-box, and I'll never own another of those, so it's Cummins for me. So far, she has been very good to me, but I treat her right.