Real world... X15, MX13, d13, or DD15???

bad thing about the cummins, the front seal goes to leaking about 650-800k in my experiences with them.
Love the cummins i have though, pulls good.
Have had less trouble out of the Dd15 then any i’ve had, less power than the cummins, but detroit is known for fuel mileage, it gets 7.3-7.7 where the Cummins vary 6-6.5, same run minimum idle.
MX13 downfall, if you don’t know someone who can fix it, stay away, pete/kw dealers are about it on getting it fixed, and they’ll burn you.
Wasted 18k earlier this year at KW dealer and what i told them to do was finally checked, after 3 months.

Pin from computer had one cracked, one broken pin and it’d lose connection going down road and show misfire on cyl 6.
so after rebuilding cyl, new injector etc, they finally checked computer(which i asked for in first place) and it’s repaired.
A $500 part cost $18k.

check @Arctic_fox for more wonderful insights in the wonderful world of Mx13s.

 

Today, I’d rank them DD15, mx13, x15. I’ve not had a lick of trouble out of my MX13’s, but the Detroits seem equally robust, with better service access. The Cummins has a higher incidence of mechanical issues, based on what I see in the shop at the local dealer and from what their service writer tells me.

 

My FLD with a N14 I drove over the last 15 years. I did most of the maintenance and repairs. Last couple years I took truck to mechanic for most repairs. I still did most of my LOF's.
I bought a 2017 Cascadia with a DD15 with 500,000 miles in February 2023. About 80,000 miles later had to replace the DPF's in the 1 box. 20,000 miles later the NOX sensor needed replaced. My biggest disappointment is I have to take the truck to someone with a computer to clear the codes after every emissions repair with a code and an emissions warning light on.
When I replaced the NOX sensor, I had all the sensors on the 1 box replaced. Save time and money going to Dealer once to have old codes reset.

The mechanic I use for most of my repairs (he is a one-man shop) he doesn't have the tech to reset the newer trucks computer. He does have a fuel primer to change the fuel filters that Detroit recommends. When my barrel of oil is empty, I doubt I will get another. Let mechanic do all the maintenance.

I really like driving the new truck. Definitely a little smoother and much quieter ride. My old truck I didn't realize how loud the road noise was. Now I can listen to the Fm radio without blasting the volume.
The new truck I didn't like the slow acceleration, kind of got used to it now. Plenty of power. Fuel mileage is great. Some runs I used to get 3.3 with my old truck, now I get 4.5. Old truck MPG was 6.2, same run I now get 7.4. My trailer is a step deck, running empty I got 11+. My average since I bought the truck is 7.4.

I don't like the required ELD, getting used to that as well.
Good luck

 

I’ve had no personal experience with anything on the list other than the Paccar. I bought my previous truck with 240k on it and sold it with 600k on it. Mechanically all I did was a starter and a water pump. Emission-wise it was 2 sensors. Preventative I did have the DPF cleaned at purchase, I replaced the DPF after that, and had the new one cleaned once before I sold it.

My current truck has 207k on it now and so far I’ve had to replace one injector. I got a notice a couple weeks ago that Paccar is extending the warranty on injectors for the EPA21 engines to around 500k miles. That must be their way of getting around doing an all out recall on them.

Both of my Paccar engines were 510/1850. And I will say my experience has been different than others, and some of the 455/1650 ones seem to be problematic. Also with a Paccar you need to make sure and do the recommended services when they’re called for. And without knowing the history of the trucks you’re looking at the emissions could be a crap shoot on whether things have been done or not.

 

Fix the glider…..

 

All my friends who bought emissions trucks with 500k miles deeply regret that. Literally never ending issues with everything especially with def stuff.
You gotta buy new, so you take good care of it, or buy another pre emissions truck and rebuild it.

 

I just looked on Truckpaper and there’s around 100 Freightliner gliders, some in the 200k mileage range and the prices aren’t all that terrible.

 

OTR Performance® - The source for advanced diagnostics

Get one of these.
Keep in truck, saved me a bunch over years, can force regen and clear codes.

 

Of the ones on your list
DD15.. almost every shop in the country can work on it.
X15... almost every shop in the country can work on it... I have a 2015 isx15 fuel mileage avg is 7.25-8.25, 10sp auto.
MX13... less shop can or will work on it
D13... for the most part only Volvo can work on it.