Fuel Economy on Different Platforms

[P51bombay]

Just looking for input on expected mileage when comparing different platforms with a similar size cargo area (ignoring the GVW capacity)

Current truck is a
2003 M2106
3126-225/6spd
Single Drive/254WB
24ft box
9.2 - 9.4 mpg

Option 1
Kenworth T800 Straight truck
ISM 425V/13spd
Tandem Drive/200WB
28ft. Box

Option 2
Kenworth T800 Tractor
ISM 425V/13spd
Tandem Drive200WB
28ft. pup, single axle

Option 3
Kenworth T370 Straight Truck
PX-8 330/10spd OD
Tandem Drive/275WB
28ft Box

Option 4
Kenworth T370 Straight Truck
PX-8 330/10spd OD
Single Drive/275WB
28ft Box

Most days loads would be light, say under 10K

The reason for all this is when discussing equipment choices with management (one person really) there is a reluctance towards any sort of tractor due to a previously unprofitable tractor pulling a 53. (which was rarely if ever filled)

My thinking is a SWB tractor, somewhere around 200 - 225"WB with a 28 pup will be the better option as it will be more maneuverable while being only slightly longer than a ST, mileage will be virtually identical to a tandem ST, cost isn't much greater than a ST while being more flexible with loads, GVW is obviously greater, (can't go after more freight if you can't handle the weight) not to mention durability factors. Also IMO, the when comparing the ISM and PX-8, the ISM wont be working as hard as the Paccar will and therefor mileage will be good.

So what do you all think, when lightly loaded can option 2 be expected to return in the neighbourhood of 9mpg? Ideally I'd like to see some hard test data - would Kenworth have such figures? I see test trucks from the Paccar Technical Centre around here every so often so surely they must be testing the stuff. In fact just this afternoon I saw a W900S straight truck with some sort of test rig on it - looks like some sort of sliding simulated load.

 

[davekc]

Need to know what size rear ends these trucks have. Any one of them could be significantly different without knowing that.

 

[P51bombay]

hmm..........well, I really don't know - they don't exist. What I meant was all else being equal in the specs. You wanna plug in a common figure?

 

[davekc]

Kinda hard because your 6 speed M2 isn't going to have the same setup as a 13 speed.
Without that information, it would be like throwing a dart and picking one.

 

[gojack]

I am running a tandem Volvo VNL300/Cummins ISX475/Freedomline/Super Singles
Pulling a 53' dry van.

With light loads, under 10k, I'm at 7.5-8mpg (at 60mph)

Forget the T800... think aerodynamic, Cascadia, Prostar or VNL780
A square nose will cost you 1-1.5 MPG.

fuel economy = Low weight, Aerodynamics, intelligent transmission and low rolling resistance tires.

So;

Reduce engine HP and weight with a ISM instead of ISX 2181 lbs vs 2940 lbs
Strip out one axle on the tractor,
Strip one axle on the trailer,
Lighten the trailer from 14,000 lbs to 8,500 lbs (by going to the pup)

with a properly speced truck you should be in the 9+ mpg range.

_____________________________________

That said,

I would get a single drive axle tractor w/lower HP ISX (could be turned up if needed) with a lift axle or long enough to add a lift axle. That would leave open the option to drive for anyone/pull anything. Al rims and Super Singles.



The advantages of TT vs ST are almost endless...
I have had a Sprinter, a Pete 335 and a TT, TT is the way to make money for me.
Trailers are cheap, you could have several if needed,
a little flat, a city pup and a 53.
If you have a customer who wants to drop and hook, you can get a 53 for 4-5k
Quality used TT's are a dime a dozen...
Quality sleepers are standard, not an expensive custom option.
And they are built to last and last.
You can drop trailer and go eat etc... while being loaded/unloaded
drop trailer at truck stop/Walmart and park anywhere.
pull anyones trailer(s) drop and hook.
switch to pulling reefers or flats or DD's etc..,

I will keep my tractor FOREVER and just replace trailers as needed.
Tractor life is in Millions of miles.

 

[Tuckster]

Is it really that easy to drop a trailer and go get something to eat ??

 

[gojack]

Is it really that easy to drop a trailer and go get something to eat ??

Dropping the trailer -drop landing gear, unhook lines and lock kingpin- takes about 2-3 min.
Re-hooking takes about the same.
Knowing where you can drop a trailer... Priceless.
(I would not drop a loaded trailer anywhere but at a yard or in a dock.)

I have also had no problems parking near the dock at Walmarts, Meijers, Lowes etc., and walking for nearby food. A little more walking, but hey, I need the exercise.