Here's how I would spec out a new truck
 

First of all, here is a good list of specs you can get on all trucks, although not 100% accurate:

http://www.etrucker.com/apps/news/article.asp?id=65871

Here are the trucks I would consider, I would exclude anything not on this list:

Volvo vn780
Freightliner Cascadia
International Prostar

These trucks are the top 3 aerodynamic models out there. I wouldn't consider anything else.

First we'll talk about the specs common to all 3:

- Aluminum wheels all the way around
- XZA3 steer tires
- XDA energy drive tires, or if you can XDA X-one super singles
- Amboid style differentials model MT-40 "amboid style"not the common RT "hypoid style meritor style diffs - better driveline angles and more efficient. They're like the mack differentials.
- 2.64 gears
- Disc brakes bendix ADB22X
- 12000 lbs taper leaf front suspension, not air
- Haldex "lifeseal" brake chambers
- auto-grease system
- full gauges
- full aerodynamic fairings
- 120 gallon tanks with locking fuel caps
- Delco Remy 36 SI HP alternator, pad mount
- "straight" air lines for trailer hookups, coiled air lines are garbage
- Long life driveline, meritor RPL20

The Volvo:

78" sleeper (42" wide bed claimed)
485 HP volvo D13 engine
Volvo I-shift Model # AT2512C (direct drive) 12 speed with eco roll and "hill start"
Full rear fairings(like the swift trucks) including spoiler

I was told bendix disc brakes will be available in the fall


Cascadia:

72" sleeper (40" wide bed claimed)
455/475 DD15 with 1550 torque (wait a year and go with the DD13)
Eaton Ultrashift 10 speed direct drive model #FM-15D310B-LST
AF-12-3 front axle to facilitate:
Rack and pinion steering
Right and left hand side "access doors" yes they're expensive, but safety is important
Delete those stupid cupholders on the floor
Alliance AGM batteries

I was told bendix disc brakes would be available in 2 months

Prostar:

Cummins ISX 450 HP 1550 tq
Eaton Ultrashift 10 speed direct drive model #FM-15D310B-LST

I don't know when bendix disc brakes will be available for the prostar

Here's a link regarding the new amboid style diffs:

http://www.universaltruck.com/tech_library/sp0167(2).pdf

I think out of the 3 the Cascadia will get the best fuel mileage. 8+ MPG wouldn't be out of the question.

Also here's a RPM/MPH chart(use the red line):

http://i130.photobucket.com/albums/p.../direct264.jpg

Now that summer is at at least playing hide and seek with us, I've managed to get into the low 8's average (6.5 US). The other big motor guys are still getting 5 US. My CPM is ~.65 and there's is ~.95.

I've been doing around 8 US, one tank I did was 8.7.

My dad bought almost the exact same truck as mine, just a year newer. Same 425 hp volvo engine, same 3.73's, same 13 speed, etc..

I expect him to get even better fuel mileage then me. Right now I have XDN2s and he is going to get XDA energy tires soon. 5% difference right there.

Why would you go with the Cummins instead of the International engine?

Bigger fan of cummins. Don't know much about the new international engine, but I do like some of the stuff they're doing like the CGI(compacted graphite iron) block.

the volvo d13 is junk.... maybe next year they may have it working better. i don't think 8 breakdowns in 114,000 is good and all motor related. it now has a NEW head...!

the d13 has been so bad that the company we drive for has stopped ordering them until fall

What kind of breakdowns have you had?

injector cup, flex pipe, water pump, injector cup(pulled head), ran overhead(no jakes), spun cam bearing, injector cup, replace head, thermostat housing, 2 injectors, injector cup (a week after having NEW head installed). steering box seal. i know i forgot a few of the little things.

So why not a 13speed or 18speed?

My guess is that they are heavier and maybe not as efficient as a 10 speed. Most of what he speced was directly rated to efficiency. I might can see some advantages to those in improving economy over a 10 in some of the more mountainous regions of the country. If you are not running out west though a 10 speed should suffice. The days of O/O specing out all the lavish high h.p. and fancy 18 speeds are beginning to become numbered as are the classic hoods. I live in a small town that has about 6 or 7 small mostly O/O outfits and i cannot count all the petes and kw I see parked for sale right now.

Hamboner got it half right. Cost, weight are two big reasons.

But the biggest is efficiency. I would NOT spec a 10 speed overdrive, I'd rather just go with a 13 speed (they're all overdrive).

That specific ultrashift, or the I-shift are both direct drive. Saving about 2-3% in fuel. That's a lot of dough.

All Schneider trucks are direct drive.

Here's what I said on another forum, explaining the specs in more detail:

Like i always said if you cant make money with a hood then you got some real problems.

I just don't get it and I would really like to understand it. I always thought an overdrive was better, get the motor spinning slower at higher road speed. Slower is better right? I am spec'ing a new truck right now and I have preliminarily selected an 18 speed, but am open to ideas especially if I can save 2-3%. I already do 7.5mpg with a 13 and c-15 with 3.73 and 24.5's.

In todays fuel market I believe in doing anything to increase my MPG and nothing is off the table.

What you want to do is have a direct drive with a certain gearset that allows the same overall gearing as a regular transmission.

I'll explain:

Truck one, 10 speed direct drive, 2.64's

Truck two, 10 speed overdrive, 3.55's

These trucks have the same tires. Every gear will be within 1% of each other(overall ratio) and the cruise rpms will be the same. You're giving up gearing at the diffs, but you have more at the transmission.

The two advantages are:

1) Power is going direct through the transmission. No power is going through the two countershafts, then back to the output shaft. It is going STRAIGHT through.

2) Nearly everything is spinning slower, back half of the transmission, all the driveshafts, etc.. This lowers losses as well.

The trick is finding a combo that will work for you. If you're hauling more then 80,000 lbs, no go, because there's no direct drive transmission rated for that. Going fast? Again no go, because even 2.64s have too much gearing for going fast(never mind 2.79 or 2.93's). Play in the mud a lot? Not a good idea, because the driveshaft is seeing about 33% more torque.

Basically if you want to do a direct drive setup with efficient tires, you cannot go fast at all, as seen by the chart I posted above. Sure one could go with 11r22.5's, lo pro 24.5's or 11r24.5's but those tires are not as efficient, XDA energy tires are also only available in lo pro 22.5. Super singles are the same diameter as lo pro 22.5's.

Says the company driver staring at a dogs butt all day :lol:

I admit I do have a hood but if I could save 1mpg without one I would do it without even thinking about it for a second(for the next truck). Think about it...

100,000 miles at 5mpg=20,000 gallons@$4.25=$85,000
100,000 miles at 6mpg=16,666 gallons@$4.25=$70,830

Straight to your pocket savings of $14,170.

Thats why everything I do behind the wheel is done for improving my MPG.

Wow each 1/10th is worth 1400 a year.

Never thought about it that way, kinda makes me feel better as I motor down the highway at 60 in a 65 with swift passing me.

My mileage went up 5/10's in the last month. Now that I'm able to use some downhill momentum to climb the next hill without blowing tires off. Before I had to ride my jake all the way down to keep my speed under 60mph, as soon as I went over 60 for more than 10 minutes,...off came a cap.
My IFTA says I averaged 7.9mpg for the last quarter, which should be fairly accurate since I idled only 25 hrs during that quarter.
I only idled 5 nights the entire winter, I spent less than $100.00 on propane to keep my truck between 65 and 75 degrees, and that also included always having hot water and the stove.
If I had idled it would have cost me over $3,000.00 in fuel,...instead it only cost me $100.00 and if I add the propane unit,tanks, regulators,hoses,..the entire set up cost around $350.00, so thats a whole $450.00 to keep my truck warm all winter, and I was OTR the entire winter, and I used the propane heater all the time the engine was off.
This time out I'll have opened my exhaust up by adding another muffler, reconfiguring my genset mount (so I can use it finally). Also I'm sticking to the East coast, and not crossing the Rockies anymore.
I wanted to get a direct drive tranny, but I ended replacing the one I had with the same model.
Again, I still drive 55 unless I'm rolling through mountains, then I just her her do what she wants.

Doghouse I'm pretty sure you already have a direct drive tranny.

Allan,..I'm really not sure,..I asked for one and the guys who sold me the unit said that 9th was the direct drive gear and 10th was not. Then again,..they were bumbling fools anyway.

You have 2.64's or 2.79's right?

If you have those gears, with an overdrive transmission, your rpms would be ridiculously low in 10th at 60 mph. Around 1000-1100 rpms

What gears and tire size do you have?

410 rears and 22.5 lowpro's. My rpm at 55 is 1,450

Couldn't have said it any better than that! I like the hoods as much as anyone but to sacrifice so much in todays economy and fuel prices is ridiculous. I prefer to pocket as much money as i can in any job. I dont have an ego that needs to be justified by driving something everyone else will think is cool. Guess that is why i ride Roadstar instead of a Harley.

Yes that will be overdrive.

You would need to put a direct drive in there AND change the gearset.

If you didn't you'd be at 2100 rpms at 60 mph :P, or 1931 at 55 mph.

You have a 11.1L detroit correct? What are you getting for fuel mileage currently?

Do you find the revs are too high? 1450 sounds good at 55 for that engine.

2.93's would put you at 1380 at 55 mph (with direct drive swap as well)

3.08's would put you at 1451 at 55 mph (again with direct drive)

Geez Allan for being such a technical guy WHY aryou calling the wide-based tires SUPER SINGLES?? That was the name for the old high profile singles not the NEW STYLE! OK rant over carry on. LOL

sorry "wide base singles".

Most of your specs are pretty much what I've been working on as I look to a new truck this summer or end of the year. Unfortunately, I can't get what I really want...Prostar with the DD15 and the I-shift. Guess I'll have to settle :cry: :lol:

LOL no worries, that's the boat I'm in. Although I think I won't buy a new truck for many moons. My dad was looking at buying, but found a good used truck and went with that.

I think what I would do is wait a year and go with the DD13.

Well...I really do like the looks of the new International "Lonestar". Saw the real deal thursday while in Ft. Wayne IN. Very sleak looking unit. Very comfortable looking interior. The test-driver let me up on the running board to look inside...but wouldn't let me enter the door.

I want one.

Signature 600 Cummins, 13 speed auto, 390 rears, half faring package, 255" wheelbase, "super singles" on the drives, leather package on the interior, 72" sleeper, fridge, apu, and the premium sound system !!!


Gimme that "Binder" now...I'm tellin ya!!!!

I'm not sure I want to go with the smaller engine. If everything comes together, I'll be running back and forth between the NW and Chicago...lots of mountains. Truck sales are so slow this year that pricing is pretty attractive. I don't think that's going to be the case next year. Not to mention the fact that interest rates are not likely to stay low. I figure if I buy by the first of next year, running it 3 years allows me to avoid the 2010 engines until they've got 2 years under their belts. I'm more worried about bugs in those engines than I am these new ones now. Plus, as it stands right now I've decided that SCR is looking like the way to go. It won't hurt to give them an extra year or two to build out the infrastructure.

What is "SCR"?

Selective Catalytic Reduction. Basically they inject urea into the exhaust to reduce NOx.

Some manufacturers have stated they are going that way, some are not.

Blah blah blah kevinite....... :lol: :lol:

Makes perfect sense. I would have never guessed it in a million years.

Now on my 13 speed if I ran in 7h (non-overdrive) at 55mph would I see even better mileage or do I just need to keep doing 60 in 8h?

I'm getting 7.2 (last I checked 2 months ago) loaded, and 10.7(also two months ago) empty. It seems to be doing even better now with the new tranny/tires,..I'll check it next week when I head out.I wanted to change the drive train when I got the new tranny, but it seemed too complicated for the shop to do. My cruise control stopped working 50 miles after I left their place the last time.
I don't think there are any issues with my diff's even though they have 980,000miles on them. They came with synthetic gear oil and don't leak, so I'm probably better off keeping the truck with stock spec's.
I have the 11.1 and 1450 is the lowest I can run this engine,..it falls flat if I drop below that rpm. Its running a bit hot, but I think thats because the engine can't breath through the single muffler, I put on duals and it seems to like the less restricted exhaust. I might also get a fairing for the roof, to help the air up over the sleeper. There's a 17" high wall for the air to hit above my cab.
I toyed with going with a taller 22.5, but still decided to stay with the trucks stock spec's.

Possibly. Find out if on your transmission if 7h is direct drive or not.

Doghouse, put a fairing on it! That is the single best way to improve fuel mileage (if you mostly pull vans). Way more than slowing the engine down a little. You should see 0.3 - 0.5 mpg improvement. More if you're still running 68 ar more.

He pulls flatbed.

You forgot about using an 18 speed with tall rear end ratio. The 18 is more than adequate for heavy loads. You can run in direct (16th) with 2.64 or 2.79 for maximum economy, you have splits into the basement for hard pulls, it has better lower reduction than a 10 or 13 even in reverse, and you still have two more gears up on top that could be used efficiently on flat ground, light loads, no winds, bobtailing, etc. Just spec a drive shaft combo that exceeds what you are putting down by 25-30% and it will handle torque quite nicely.

I looked up the number and a 10 speed direct has a 14.8:1 first compared to a 14.4:1 first on the 18 speed. Not much difference. The problem is I think doing this is useless because the 18 speed simply drags a lot more than a 10 speed ever would. I would consider a 15 speed deep reduction with a 1:1 final over an 18 speed any day of the week, especially hauling heavy. But they don't exist on truck paper. But speccing new they do.