Marc

Good idea about the odometer though... I will get one of my other crews to follow me to a job site and compare !

It may have been less then my estimated 600 kms for the first tank , it could have been mid 500' s (340 miles) as the odometer was in the 200's when purchased and my first tank was in the 800's . .. I should have converted to miles ... I'm getting right around 150 mile out of a 21 gallon tank which is 7.1 mpg . I'm fortunate that my normal cargo is fairly light , I bought the 3500 because I tow a dual axle dump trailer with loads upto 2 tonnes . I'm not using my has milage with the trailer here , its ridiculous when I tow but that's understandable ..it only happens once a week or so.

I have a new 2019 nv3500 cargo 5.6l high roof I'm at 2000 kms . The first week I had it it was great , I didnt reset the trip odometer but the van had 230 kms on it and it was at over 800 kms when I next filled it up so I'm guessing I got about 600 kms per tank, i was pretty happy about that. Van was loaded with all my tools. After the first week I started noticing a knocking sound, more of a clicking really, I just assumed it was a bad pulley run by the accessory belt , since i dont have a local nv dealer close to me and since I needed the van i kept using it . After a couple of gas fill ups I knew something was wrong , hoping maybe because u can literally see the gas gauge drop . I started keeping a record and I was getting 240 to 260 kms per tank ... I started trying to drive it easier, started having my crews pick up the materials in our other vehicles to keep a consitant weight (approx 600 lbs with shelves and tools ) no ladder rack) and it stayed consistent around 240 kms . I brought it in for service , after a week and a half they changed both the air conditioning compressor and the fan clutch and can not find the source of the knocking . The knocking goes away with the accessory belt off . I think the fuel consumption and the knocking are related but all their diagnostics show the engine performing 100 % ., they are convinced it's just a minor issue that they will get to the bottom of and want me to keep a milage log to show the fuel consumption . I dont completely disagree but I'm hoping there's a bigger issue here as this thing is a fuel pig. I was hoping someone here may have had a similar issue they could share with me , and someone with a 5.6l high top who could share has milage info to see if this is normal or not..