Cummins engine ISX 450 hp? Please help.

I am a driver for May Trucking, I am driving a 2015 freight Cascadia with a 450 Cummins ISX motor manual Eaton fuller Trans, and though we are govern at 61 mph I am getting at minimum 7.5 mpg, average between 7.7 to 8.2 mpg, max mpg I have gotten was 8.5. I got in the truck in October 2014 with only 3000 miles on it, as I type this on here its now 3/20/16 and truck has 145000 (give or take a mile or two) and other than normal P.M.'s it's recently only been in a shop 1 time for the temperature sensor behind mirror drivers side replaced that's it. It doesn't use up any oil, I think I have only added 1/4 gallon in the truck the entire time I have had it. So far it has served me very well.

 

How is may trucking on the maintenance of the trucks? oil change at XXX miles etc.. I am looking at getting on of the 2012 with the isx 450 in it an old MAY truck.

 

Im getting one end of may doing a Dyno 1st on 338,000 miles

 

Loan mountain?

 

I'm not looking at lone mountain.

 

I have a used 2012 with a Cummins and I have been very impressed. I have 28k miles on it so far and am at 8.1 MPG in a Peterbilt 386. Very happy with it.

 

Yes lonemountain

 

Pull the same freight you get the same milage. Nothing about the color of the engine determines milage. Anything else now days is just advertising BS.

Automatic does not get better fuel milage unless you have crappy drivers. Your drivers can't shift get them autos, or better yet, get better drivers. The auto milage thing is just another advertising scam. The thought is by using a computer to shift your trucks all your trucks will shift the same; this will factor out the milage of your crappy drivers and if you have a lot of them, your fleet milage will improve. Of course they don't mention if you have a fleet of average to good drivers an automatic will provide worse milage.

I am in a mixed fleet of about 25 trucks and 50 drivers. Most of the motors, transmissions, and manufactures are represented: ISX, DD15, DD16, CAT, Maxforce, Paccar, 9-18 speeds, auto, - All fleet spec. day cabs. On the same run all the trucks get the same milage. Their is so little difference it is astounding. In fact if I am away from work a day or two, I can tell by the fuel consumption where work was on my days off!

Just think about it. All the manufactures have to meet the same emissions standards and they are just barely doing that. If one consumes more fuel then then others it will put out more emissions. Their is no holy grail in the engineering of the combustion of diesel. Things have been refined in recent years.

Pick a manufacture that is safe, reliable, and gives good service and go with that. Spacing the truck to fit your needs is where you achieve better milage then the next guy: not the brand, not the auto.

 

When I start truck about 1 min. It starts smoking missing and I shutoff

 

Cummins ISX engines have reported significant issues with the DPF and DOC system. They require regular maintenance so ensure your regeneration system in the truck is working. If you are willing to, buying second-hand replacement parts for Cummins engines can be less expensive as they are widely manufactured in all semi-truck makes (International, Kenworth, Peterbilt, Volvo etc.) and therefore cheaper due to commonality.