Haven't filled up yet, only been driving errands lately. But the fuel needle is definitely promising - I have about 322 miles and whatever number of miles the inaccuracy 31" tires adds - about 6%. So maybe 340 or so and the needle is just below half. Normally by now the needle would be at 1/3 full.

I will be putting huge miles on it though starting next week. My little consulting company that consists of three employees(me, myself, and I <img src="/forums/images/graemlins/smile.gif" alt="" /> ) just got a contract with a company 50 miles west of here. I'll be putting 500 miles a week on it starting then.

NCDiesel

I also have K+N and only 225's

The results are in - Just filled up last night.

I had 370 miles of stop and go, warm the truck up in the morning, 20 mile at a time errand running. Then I had about 120 miles of highway driving (65mph on my 31 inch tires). With a speedometer correction of approx 6% (arrived at by a GPS test last January) I am estimating I had 515 miles on the tank of fuel. Took 19.86 gallons to fill up for a mpg value that is a gnat's leg short 26 mph

Before the K&N air filter installation, 25 mpg is the best I could have hoped for in these circumstances. My conclusion is the K&N added pretty close to 1 mpg.

NCDiesel

Well, 26 mpg is pretty good for that size vehicle with brand new turbocharged power. The K&N air filter should help the engine breath much better and gains in HP and mileage is usual. What size fuel tanks did the 2-door and 4-door Trooper diesels have? That is a question I'm surprised I haven't asked earlier on this board.

21.9 gallons is what my owner's manual says for my 4 door. I think it is the same for the 2 door but couldn't find any verification

NCDiesel

At the risk of being labeled a flamer...
The listed fuel capacity may not be what you actually can cram into the tank.
For the purpose of this discussion I'll ignore the various warnings about overfilling the tank.
If you want to REALLY know how much fuel you are using you need to find a way to fill the tank up the same way and to the same level each time.
Same way: Lets say on a level surface, or at the same filling spot pointed in the same direction.
Same Level: Can you observe a place in the tank or filler neck to fill up to? (Don't forget to burp the tank also to get the air out.
Eric

I have to agree with kravdraa about the consistant fill-up proceedure. This is the only way to be accurate on the MPG figure. I do the fill-up to the top, minus the air-bump. I fill it myself usually at the same pump every week.
There are people at work that claim they get X mpg, but until they do it properly, I don't value their figure. And usually it's rather high, ie: "My 1998 Dodge 3/4 ton 4x4 extended cab used to get 34 mpg on the highway towing a 40ft trailer full of lead!"


Ya, uh huh. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />
Ok, maybe an exaggeration, but you get the point.

Ok, I'm done now. <img src="/forums/images/graemlins/shiner.gif" alt="" />

HEY SPENCER the fuel tank is suppossed to 21.9 gal 86-91 dsl and gas 2 and 4 dr , and one other point i might add to z-mack and kravada (sorry if i got your name wrong), when you fill up , let it set for about 30 sec or so , so the foaming will go down as it has a tendancy to kick the pump off , the bigger the tank the worse it seems to effect them, hey Zmack i can go you one better on the milage boast, my 71 dodge 1 ton van with the 440 magnum and dual fuel tanks (70) gal total will go an astronomical 700 miles , lordy for a dsl in that thing, i can live with out the acceleration but sure would love to get around 20.mpg, it gets the same milage sitting still as it does going 70 towing a trailer ,filling this thing up will weaken a credit card it just goes limp,, take care guys Jerry

Definitely use the same procedure everytime. Last three gallons go in real slow to eliminate foam and then grab the fender well and pull up the truck to get the air every time too. Then fill it until I can see the fuel level towards the bottom of the neck and stays there.

I had a small checks and balance too this last fill up. In my truck, the idiot light winking on and off means about 2 to 2-1/2 gallons left. I had no idiot light but put twenty gallons (19.86) in a 21.9 gallon tank so in my case I am certain my fill up was complete.

NCDiesel

If you do a running tally of your fuel usage (over many gallons/miles) then inconsistent filling doesn't matter soo much.

My rangie (with 4bd1t) does a steady 8.5-8.7 km/l no matter how I drive it. If I gain on one tank I can be sure the next will be a bit lower to bring it into line again.