fuel mleage

Check your driving style before you go sinking TOO much money into it. 62 mph doesn't mean much...it's how you got there. Did you mash the gas and wring it out in every gear on your way up there? Or you drive as though you had a raw, rotten egg between your foot and the throttle...and if you pushed too hard too fast, it would break and release a noxious odor? Do you stay in the throttle longer than necessary and apply a lot of brake at intersections? Race up to red lights so you have to stop at 'em? Or do you ease off the throttle early and try to time the lights and traffic so that you don't have to slow down any more than necessary? Do you tailgate other motorists? Or do you leave a lot of space?

How you shift the truck will also play a big factor in your fuel mileage. Do you bump the rev limiter in every gear? Or do you only accelerate enough to slip it into the next gear without lugging? For the lower gears, you don't even have to bump the throttle up much past idle to slip it into the next gear...and as you move higher through the gears, you run the RPM's a little higher. Again, the goal is to find the next gear low in the RPM range, but not so low that you lug the engine. It's called "progressive shifting".

I'm not too familiar with the Cummins ISX engine to know where exactly the sweet spot is...but 1450 seems like it might be high. Switching to 11R22.5 tires will drop 100 or so RPM's at 62 mph...it would be like pulling the 3.73 gears, replacing them with 3.55, and keeping the LP22.5's. Cheaper to replace the tires. As has been stated, if you rarely (if ever) get off pavement, and you seldom (if ever) see snow, get ribbed tires...all position or steer tires....mounted all of the way around. You'll see a fuel mileage improvement there, too.

So far, apart from buying tires (which you would need to do eventually ANYWAY), you are out $0 chasing better fuel mileage. Those are the best kind of changes to make, because the pay-off happens immediately. Once you get that figured out, you can use the savings you see to make further upgrades.

To put your situation into perspective, my truck is polar opposite of everything the "experts" say to do...it's not aerodynamic...I run heavy...I run the speed limit...I have the most aggressively lugged 75 mph rated tires I could find...and I've got a little more than 12 feet between the back of my cab and the front of the trailer. I have tall rubber on 24.5" rims, so my 4.17 gears turn about the same RPM's as your 3.73's and LP22.5's. I have 18 gears to get through while getting up to speed, and 460 HP under the hood. While we don't have Appalachian or Rocky Mtn. quality hills, I am pretty darned close to the Ozarks, and spend quite a lot of time in the hills near the Mississippi and Ohio rivers, as well as climbing up onto coal piles and out of rock quarries. I run a lot of local/regional type stuff, with occasional long hauls thrown in for spice.

I STILL average 5.6 mpg on end dump...5.9 on pneumatic tanks...and top 6 mpg pulling a dry box.

 

for the muffler try a donaldson m100463 its cheaper than pp muffler. and its the same muffler.

 

Believe it or not, I actually picked up close to .5 mpg with the Pitt straight through muffler. Can't remember how much they were. Try checking their site.
The average field distance from the farm is about 5 miles. Hauling liquid manure and grossing 100k+, I went from 2.25/2.3 to 2.7/2.8 mpg. I know this mileage sounds too bad to be real, but for this application it's reasonable. Lots of tough pulls and never really reach any cruising speeds.(lots of upshifting/downshifting.
Anyway, the mufflers made my truck slightly louder than stock and gave it a nice throaty tune.
I also use to use Lucas fuel treatment, and that also gained me a few tenths, but I can't remember exactly. Nobody sold it locally so I stopped using it.
Hope this helps
Floyd

 

Make yourself a fuel log, and update it religiously. Its the best way to keep track of how you're doing, otherwise you're just guessing. What you want to do with it is to divide your trips down into smaller legs - whatever is logical, figure your mileage for each leg and overal for the trip.

Now that you know what you're doing, take the suggestions you see here, and change what you're doing using only one different technique at a time. Work it for long enough to see whether that helps or not... I use around 2 weeks. If it helps, keep it, if not - toss it. I've gone from 6.3 to 7.5 mpg in an '07 Century. I pull 48-state heavy reefer.

How you ballance your trailer between the drives and the tandems makes a difference too. I find running about 1000 lbs heavier on the drives when loaded makes a fairly big difference - as much as .5 mpg. Empty, always slide the tandems all the way forward.

If you change tires... stay with the low pros... less sidewall flexing, whcih will help to keep your mileage up. Also, go over to Michelin's website. They have a tire rolling resistance calculator - it makes a huge difference to get low rolling resistance tires. Many of the more popular brands are included... not just Michelin.

 

ironpony

Are you sliding the tandems forward to close the gap under the trailer, or is there another reason?

 

Truck Pro has the same one without the name for half the price... I know someone that got theirs thru Freightliner for even less than I paid. I know I priced front springs and got my best deal from INTL... Nearly 1/3 less than anywhere else

 

The weight distribution between the drives and the tandems affects your fuel mileage quite a bit. I can probably pick up between 0.5 and 1.0 mpg deadheading with the tandems all the way forward.

 

Now they are around $160 or the "sport" model which is louder is $189

 

Yea I'm just a firm believer you get what you pay for. Some people say there is no difference in store brand versuses name brand but I disagree.
Besides, what are we talking about.$80 bucks? You can make that up in 2 weeks of a .5mpg gain

 

QUOTE=losttrucker;1369266]Yea I'm just a firm believer you get what you pay for. Some people say there is no difference in store brand versuses name brand but I disagree.
Besides, what are we talking about.$80 bucks? You can make that up in 2 weeks of a .5mpg gain[/QUOTE]


I had this discussion with a driver when buying injectors. Buy OEM! Buy OEM! My point was that Company "A" doesn't make the product but rather buy it from "B" and due to smart marketing have managed to put a higher price on it just because of the name. IE (not Literal) Ford buys injectors from this factory, gaskets from that one and pistons from another then puts it all together in a package as genuine OEM.