latest mpg

Yesterday, My truck amazed me totally by getting 15mpg, over 300 miles, then repeating it (almost) by getting 14.8 over 400 miles, I am hoping that this is something it wants to do all the time..

I have found a new happy speed, also.. My truck prefers to trundle along at 58 mph. I have two options about this - as it increases the fuel mileage I have to take notice, so I can either accept it, and get used to it.. Or, change the ratio in the back end, so I can go 2000 rpm, at a speed higher than that. I really enjoyed getting 15 mpg.. That made the trip a very enjoyable on - I went to Davison, Michigan for the second time in seven days - what made it even more remarkable was that I had done the exact trip on Wednesday, with a fuel mileage of 12.3... The traffic was bad for the first half of the trip - which made me keep below 60.. Strange way to learn just how much money you can save keeping the foot out of it, eh?

Mylash

better mileage for me would be nice with the 5.13 gears in the 4x4..... but the 32 gallon tank is killing me. I wish the short wheelbase 4x4 somehow could get a 50 gallon tank!

Mylash,

You must be reaching the "break-in" point. I noticed that as I was rolling the miles on, the MPG would improve by .05 to .2 MPG for every tankfull, with the 4.44 diff. (55 - 60 Mph average). Changing the diff would make little difference, as you loose mechanical advantage over the weight of the load being propelled. Then, when you do have to pull a heavy load, chances are that you would not have sufficient torque to use O/D at all, hence reducing your overall MPG. Its a give and take situation. I experimented with that before, going from a 3.08 to a 4.00 with a 5.0L Smallblock and a 5-Speed. What I lost (mpg wise) empty, I gained while towing, since I could never use 5th while towing before the swap. Other factors were also changed, such as going from SRW to Duallies, and adding Limited Slip Differential, which also played in with the mileage, but these would have been minimal (solid 10 MPG after all the mods, towing and empty, instead of 15-17 empty/7.6-8 towing before that).

Chtucker,

I feel your pain. 5.13 is rather high, tough to keep it in the "sweet spot" on the highway. With the single 32 Gal tank, its tough to pass any fuel stop, when you don't know if there will be another before you run out!!!! You can check with TransferFlow, they do make oversized (43Gal) OEM replacements and in-bed auxiliary tanks for GM MDTs, but I'm not sure that they've developed one for the 4 X 4 version yet. Check them out. Last I checked, they were working on something about 6 months ago, but what takes time is getting certification on their products, and that's a crap-shoot. There is also another aftermarked tank maker called Supertank, but I don't have details on that. You can do an Internet search for that one, and they may have something for you there. Both make bolt-on direct replacements for the do-it yourselfers with access to a shop, which can save you some $$.

Despite these "minor complaints", these are still hands-down better than any pick-up trucks, so good luck finding what your looking for.

In other vehicles, I have a 45 gallon Supertank, and a 46 gallon transferflow.. The transfer flow fills as fitted by them in Chino, CA - the supertank took me a few attempts at improving vents to get it to fill at all, but now fills very well, using fillnecks purchased from.... TransferFlow, Chino, CA..

I have 40 gallons in two tanks in the Kodiak - I really need more, so when in California in the next couple of months, I will go see the guys at transfer flow, and see what they can do.

Theo

If you don't mind a saddle tank that should be easy to come by from a heavy truck and fit it with a transfer pump.