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Mx13 vs isx Cummins - Cummins5555 - 08-08-2020
I’m new to emissions engines just need a little help no bs about maintenance or anything cuz I maintain my truck better then should do I just need help with newer engines please either a 2015 Peterbilt 389 Mx 13 455 hp 10 speed 3.55 ratio or 2016 Peterbilt 389 mx 13 500hp 18 speed 3.08 ratio or 2015 Peterbilt 579 Mx 13 485hp 3.42 ratio or 2016 Peterbilt 579 isx Cummins 450hp 13 speed 3.36 ratio I’m just wondering on which engine is more reliable same great maintenance and all that a Mx 13 or Cummins isx I love Cummins but heard a lot of issues and can’t find a lot on the Mx 13 please help with what one is more reliable thank you
RE: Mx13 vs isx Cummins - Waterloo - 08-08-2020
I'm not trying to be a smart ass, but... You are in the wrong place then, maintenance is a very big thing here, as there is a steep learning curve to these emission trucks and motors, it was maintenance that brought most all of us here, like myself, as I was going to lose everything if I did not fix my Cummins emission motor, as the maintenance was killing me as the dealerships were sucking my wallet dry and not fixing a damn thing, they never do. I had to take this bull by the horns and forget warranties and dealerships and take care of business, that is what led me here to Rawze.com. Ask me about my in frame... Dealerships? Warranties?
These are not the trucks of the past, GTO is long gone, maintenance is pretty much all we do, and we are all still learning, I know I am...
And you are welcome to stay and learn with us, this is probably the only site of its kind on the internet for the care and feeding of the Cummins Emission motor. There are many benefits too, the knowledge here, and the fact that we help each other out, even new guys like yourself.
Ok, on to your trucks!
As far as those setups, what are you going to do with the truck? Those picks are all over the map, two I would not even go near just due to the gear ratio, and you could not give me an MX13, I would tell you why, but you stated you already know about maintenance, so I figure you know why. Odd that you would even consider an MX-13 with your knowledge on maintenance?
OK... Not knowing what you are doing, if those were my picks knowing nothing about your plans...
First pick, nope
Second pick, nope.
Third pick, nope.
Fourth pick, maybe, if you are hauling light freight in the flats, like FedEx or UPS. But that would be really stretching it, as that could blow up in your face and then you find yourself running the Rockies, so NOPE.
I don't see anything there I could make money with, I see three that would more than likely bankrupt me in regards to maintaining them... Funny, there is that maintenance word again... But you don't want to talk about that, as you already know... ;-)
Seriously, tell us what you want to do, or need to do with this new truck of yours, we will help you out, we just need more information.
As far as which motor, I would stick with the Cummins, they are a well know motor, the good, bad and ugly. Cummins gives us tools like Quickserve, to properly maintain, there is that word again, the motor to OEM specs. They also allow us to actually get inside the motor to professionally diagnose and tune the motor with their software. Quickserve and the ability to diagnose on the fly are the two reasons I stick with Cummins. I can do just about anything to the motor in my own driveway, I cannot say the same about the PACCAR/MX motors, as they give you nothing in regards to maintaining, there is that word again, their motors, unless you like hanging out at dealerships as they suck your cash out of your bank account. And I mean bank account, because they no longer nickel and dime you, they go straight for the home equity loan.
I'll tell you a story, a true story from the other day... I ran into a kid with a brand new to him 2016 680 KW, he was a company driver a week ago and just bought this truck. The truck had 500,000 miles on it, looked real pretty... But, he had check engine lights going off and a few codes. He also stated it had not regen'd for him. So, seeing as he had a Cummins, I went and grabbed my laptop and Inline reader, I hooked it up, ran his codes, it tripped on the iMap (Intake Manifold Pressure) and EBP (Exhaust Back Pressure) sensors, along with the turbo speed sensor. This was on a CM-2350 motor...
I also ran a forced regen for him. A dealer would have charged this kid what, $300 to $1000 for this service? That right there would buy him a laptop and the Inline reader. And you do not need a new laptop, anything that runs Windows will work, even a Mac, as that is what I use. The Inline reader is roughly $200 to $300 on eBay, and has everything you need to diagnose a Cummins motor, less the laptop of course.
OK, back to the kid... The regen showed good numbers, so he was good there. The SCR system was also functioning properly, so good there. Now, on to the sensors... He had codes for the Intake Manifold Pressure sensor, the Exhaust Back Pressure sensor and the Turbo Speed sensor, which looked new and was more than likely an old code in the ECM.
I showed him where the iMap sensor was, and told him the truth, that (iMap) intake manifold pressure sensor is the "New Turbo Sensor". He looked at me funny... Yep, that is the new turbo sensor! You take this truck into the dealership, and they will do everything I just did, and charge you for the diagnostics, EXCEPT, they will tell you need a new TURBO!
Instead of replacing the $40 iMap sensor, they will install a $6000 turbo for you and send you on down the road... You may get lucky and they will only charge you for the new turbo, the one you did not need, and eat the diagnostic charge... Most will not, and that final bill can be upwards of $8000 to $10,000... All this motor needed was two sensors, both would have been around $150 or so, and they are easy to put in with simple hand tools in a parking lot. I was able to help because I know how to properly maintain, there is that word again, my own truck and carry what I feel is necessary to properly, wait for it, maintain, and keep my truck on the road.
I told him to replace these sensors, no clue if he will, we could have done it right there in the parking lot, as I did have my tools with me... He left, and I am back at the house.
I was able to save that kid $6000+ in a dirt parking lot. I did all of this for him for free, and I hope some of it stuck, so that he gets proactive and learns how to properly maintain, there is that word again, and be able to diagnose his own truck. I hope you follow the same advice you have already been given in the other post you made. We are not here to stroke each other's egos, or to pick on you. We are here to learn and help, there are no clique's here, just a bunch of men trying to make an honest living.
Give us more info, we will be happy to assist!
RE: Mx13 vs isx Cummins - JimT - 08-08-2020
You're on a forum oriented toward Cummins ISX owners, so by default most of us would prefer the Cummins.
Why are you asking us to pick your truck? There's so much about your current (or future) operation that we don't know.
* How fast do you drive? - That will help determine optimal rear end ratios and transmission combinations.
* What part(s) of the country do you operate in? Flat parries? Rolling hills? Mountains? City driving? Line haul? Regional?
* How heavy are your loads? What kind of trailer(s)? Dryvan/reefer? Tanker? Flatbed/stepdeck/RGN? Do you max out at 80k or haul overweight? They all have different needs.
* What's the mileage and engine hours on each truck? - Higher miles and lower hours means less idling, which translates in to better engine and aftertreatment health. It also helps you to plan for the inframe. On these newer engines that you're looking at, based on typical driving habits and fleet maintenance procedures, you can expect an inframe somewhere around 600,000mi, maybe sooner.
* Is there any blowby? - Short of hooking up to a dyno, you can open the oil fill cap while the truck is running to get an idea of current blowby. Put your hand over the fill tube and feel the pressure, also look for exhaust/smoke coming out the tube. Greater pressure, more smoke = more blowby = less time before inframe.
* Do any of them have an APU? - Greatly reduces engine idling, saving fuel and prolonging the life of the aftertreatment systems and engine.
* What's the wheelbase? - Factors in to you intended operation.
* Have you pulled any rigdig reports? They won't tell you too much, but entries for accidents or citations could help you understand how the truck was driven and whether they had OOS violations for lack of maintenance. Neglect and/or aggressive behavior in one area usually manifests in other areas as well.
These are just some things that will influence an informed decision between different purchase options.