X-15 Cummins thread

my 2018 389 with a x15 565/1850 has been in twice with vibration issues. first time replaced ujoint and yolk on front input then next time different brand of steady bearing. still has vibration. mostly under loaded super b but also mt.
as far as x15 engine has been great, no codes or issues, not happy with power above 80kms/h but still breaking in i guess
has anyone deleted this engine yet??

 

Mine had bad vibration when it was brand new. It would massage your back between 55-65. They ended up puttin new driveshafts in it and it solved my problem. Retiming my intermediate shaft fixed the shake right off the bottom. For some stupid reason the intermediate is out of time from factory.

 

And the dealer couldn’t spot that when they “dealer prepped” it........Geeze.

 

I said same thing. Problem is they are selling so many trucks I think they hit the high spots and call it good.

 

I think that's the pretty standard range for Cummins period.

 

Knock on wood I haven't had or heard of any issues with the X15. I have a X15 performance series w 525/1850 backed up by a 13spd in my 2018 Kenworth T680. I've got about 200k on it and love it. It pulls good and has exceptionally powerful Jake's. My lifetime mpg would be a little over 7, pulling reefer box cross country ranging 60-80k gross. A few of my friends have the same setup as we did a group buy. One of them has hit 300k running team, and none of the trucks have had an issue. Don't know anyone w an efficiency, I've had no regrets with the X15. I think it's the best engine on market, and plan on buying more. Get it in a kenworth, peterbilt, freightliner, or ws and you should be fine. Dont trust Volvo or international due to internal electrical issues. Cummins released to press that the X15 is the most reliable engine they've put to market as of right now, when comparing statistics to the N14 for the amount of time the X15 has been on market.

 

I’m really struggling between choosing a 500hp efficiency series or a 565 performance in a new truck. I don’t need the high HP as I’m running very light loads. I see better resale value with the 565 but the fuel mileage penalty could be much more costly than that.

 

Like any higher horsepower engine, if you drive it right, it always pays off economically. I would go with the performance. A no brainer.
Example;
My Cat was born a 435 hp. I tuned it with a 550 Brakesaver program and upgraded the turbo. The fuel mileage NEVER changed. It gets 7.0 mpg average all day long.

Edit;
Did I mention it’s so much fun to drive on the hills, mountain passes with the extra ponies ......

 

I agree with you for the most part. It’s been my experience that I could get the same MPG’s with a tuned 625hp Acert Cat in a flat top Pete as what I’n currently getting with my 579 with 500 MX13.

That being said, every truck is different. I’m concerned that if I go from 6.5mpg down to 5.5mpg along with a $700/month higher truck payment I’m going to have some serious buyer’s remorse. I’m confident that the X15 500 will be just as efficient as my MX, the 565 I’d be hoping it is but what if it’s not, you know?

This truck will be my driver’s, not mine. He doesn’t drive the truck hard butI can’t expect him to be as extra easy on it as I would be if it ends up being thirsty. I could have it turned down to a 505, but why does Cummins offer a 500 efficiency and a 505 performance? One would assume that the effifiency is going to be just that, more efficient.

The 500 would be in a 567 Heritage edition and the 565 would be in a 389. Both would be heavy spec with 3.73’s. Best way I candescribe the application would be pulling almost empty tandem vans in the mountains, mostly slow twisty highways with lots of elevation change. Aerodynamics are a non factor.

 

I'd recommend going with a performance series engine regardless of what hp you get. If you don't want 565 maybe get a 500 or 525 performance. There shouldn't be any difference in mpg, it's all on how you drive it.