Performance issues/questions

[Nordo]

Ive had my Deli now for about 5 months and we are getting to know each other slowly. So I have been watching how she runs and where she purrs best, but I have some concerns that I don't know how to deal with and I thought I might toss them out here to see if you guys might have some suggestions for me.

I have been watching the milage and noticed that I am getting about 22.5 MPG or 13L/100km. Maybe this isn't horrible, but I have read a few threads where guys are getting a lot more out of a tank. I get about 480km out of mine, but I read that some of you are getting closer to 600km/tank. Im not heavy footed, and I keep her around 3000 rpm on the hiway and that gives me 100 - 110 km/hr. I replaced the air filter as well as the fuel filter and I even gave her a seafoam treatment when I put in the new fuel filter and I add 2 stroke oil every fill. I didn't see the white smoke that most people have experienced with the seafoam treatment, but regardless I filled the fuel filter and drove it out on the road for about 80 km's when I did it, I havent noticed any change in performance or milage. Since I have gotten her she blows a bit of dark smoke in the lower RPM's as I accelerate. mostly as I am going through 2nd gear. Its not always there, if I accelerate slower, it wont blow smoke at all and it seems to dissapear the warmer the engine is, but if I accelerate faster, I always see a good puff for a second or two. If I am at hi-way speed and stable in cruise, I can press down on the accelerator and get a good puff of smoke too. It wont last more than a few seconds, but I notice it.

She runs great though. No knocks or ticks, no hesitations (other than the standard turbo lag) and I have had no issues with burning oil or discolored coolant. What might the problem be?? Could the smoke be related to timing?? or maybe rings?? I haven't found a garage to take her to here in town (Lethbridge AB) but I have been considering redoing the head this winter.

Any suggestions or thoughts, I would love to hear.

[Firesong]

I read no problems in your machine. The dark smoke is just unused diesel being put through when you hard accelerate.

Do you have an automatic or manual tranny? You mentioned being in second gear. If you have a manual transmission you will have a smaller fuel tank than the automatic. Hence less range.
If manual tranny you probably get better mileage with city driving than on the highway...lower rpms

Other things I noticed that caused a slight to medium influence on fuel mileage are tires, roof rack, fuel (there is a diff between stations).

In general yours sounds good.

[nxski]

13L sounds normal if you are driving like you're in a normal vehicle. My roof rack ads between 1L/100km-5L/100km depending on where and how I'm driving. If you're seeing black smoke when accelerating, that's not a problem, but means you're probably accelerating too quickly for maximum fuel economy. Tires do play a big role as well. I would try adding some 2 stroke oil. Driving normally, it saved me 3L/100km which seems extraordinary for a simple 300ml/fill, but I've confirmed this over numerous fills. Blanking the EGR and adding a larger exhaust also really help with fuel economy. When I accelerate, it takes me about a minute to go from a stop to 80kph. I generally travel at 80-90 for maximum fuel economy with my rack on and 90-100 with the rack off. With the rack off and normal size tires, I was getting 8L/100km if I hypermiled. With the rack on and 31x10.5" tires, I can get just a touch over 9L/100km