Fuel Economy Question

[usafk9]

Just finished paying off our first truck, and going to start saving to buy our next. While we absolutely adored driving our previous owner's Sterling, I am looking real hard at engines and fuel economy.

While sitting this weekend, I talked to an owner of a 06 or 07 Freightliner with the 300 or so HP Cat engine. He stated he averages 8 mpg. While my current engine (MBE 900, 260 HP) is considerably weaker, I average better than 10 almost always. Whatever engine I buy, I will have a 96" sleeper.

Can anyone give me their input on their own individual fuel economies? For example, what truck/sleeper/engine combo?

Thanks very much. A little fuel saving means a LOT of dollars. I prefer to keep it in my pocket.

 

[TeamCaffee]

If you do not listen to Kevin Rutherford on XM you might want to start as he talks a lot about fuel economy. He is on the weekends and at midnight each night XM 171. He also spends a lot of time talking about aerodynamics and what effects your fuel mileage such as a moose catcher, your mirrors, a sun visor, a bug shield, and your bumper to just name a few items.

Fuel is a huge expense to us and also one we can control through the truck aerodynamics and our speed. FedEx Custom Critical figures our fuel mileage for a straight truck at 9 mpg so anything over that sure starts lowering our fuel costs.

We will be buying the Cascadia for our next truck due to the aerodynamics and the fuel mileage it is all ready getting. Henry Albert has blogged on several over 8 mpg trips in a semi so just think what a straight truck will do. We feel the 2010 engines will do even better.

We have a Cat 300 in this truck and through a lot of patience on our speed and improving the aerodynamics we have changed on the truck such as removing our visor and having wide based singles we have brought the truck from 7.8 when we first bought it to consistently staying in the upper 9's and 10's.

 

[layoutshooter]

We have a M2 M112. I would NOT recogmend the M2 platform, go with a true class 8 truck. My engine, tranny, however is great. I have the MBE4000 450HP with a EatonFuller 10sp auto shift. I average 10.5mpg. My rear end ratio is 3:58. Lost of low end there when I need it and I am able to run low RPM's so my engine is hardly ever working hard.

 

[usafk9]

So many choices......

Thanks both for your input.

Bob & Linda: FedEx has ours at 10.28. Our speed is limited, and we push the 65 constantly. My dilemma with your future choice is this: I'm looking for something with a big sleeper, and no desire to go in debt to accomplish it. There is a glut of Class 7's on the market right now for a song. Myrian and I stay out for months at a time. I even considered finding a used class 8, and stretching the sleeper and frame, then adding a box and removing one axle in favor of a lift axle. Used tractors are a dime a dozen right now also.

And yes, I do listen to Kevin almost every night.

Joe: Why not the M2 platform? BTW, is your engine the Mercedes with sleeves? I envy your power and gearing. Mine falls into the 'rolls kenardly' category.

 

[moose]

Hi , Al ...
Spe'cking a truck take match more then just one thread ,
obliviously you have your ducks in place.
however , in today market , there's very few business plans that will fall into the new truck category .
i have to ask : why new ?
why class 8 ?

 

[TeamCaffee]

So many choices......

Thanks both for your input.

Bob & Linda: FedEx has ours at 10.28. Our speed is limited, and we push the 65 constantly. My dilemma with your future choice is this: I'm looking for something with a big sleeper, and no desire to go in debt to accomplish it. There is a glut of Class 7's on the market right now for a song. Myrian and I stay out for months at a time. I even considered finding a used class 8, and stretching the sleeper and frame, then adding a box and removing one axle in favor of a lift axle. Used tractors are a dime a dozen right now also.

FCC might have your fuel taxes set at 10.28 but the FSC is paid on 9 mpg. There appears to be a huge glut of used trucks or repo's on the market right now. If you can pick up a class 7 for a song and you do the preliminary steps to make sure you are buying a sound truck for it. If the truck is cheap enough you can get it paid for pretty quickly and be saving for the 2010 technology which you will need in the future to get into California and the other states that looks like they will be tag a longs. Your idea of using the lift axle is a good one and one that we will use on our next truck.

When you are looking remember CARB is out there and will happen and be as prepared as you can be. If you go with the class 8 stretch the frame and put a big sleeper on it can you get out of the truck and get into a CARB compliant truck easily and cheaply?

One of our greatest concerns is no break downs and no service failures. Any truck can breakdown any time but we try to do anything within our power to keep this from happening.

There is also CSA 2010 hanging out there on the horizon and the driver part of CSA 2010 will start being implemented in 2011. We are constantly looking to the future and trying to make sure our next truck will last as long as possible and be as versatile as possible.

Even trying to do everything right we still feel as if it is a crap shoot in the dark!

Sounds like you guys are also trying to do everything right!

 

[layoutshooter]

So many choices......

Thanks both for your input.

Bob & Linda: FedEx has ours at 10.28. Our speed is limited, and we push the 65 constantly. My dilemma with your future choice is this: I'm looking for something with a big sleeper, and no desire to go in debt to accomplish it. There is a glut of Class 7's on the market right now for a song. Myrian and I stay out for months at a time. I even considered finding a used class 8, and stretching the sleeper and frame, then adding a box and removing one axle in favor of a lift axle. Used tractors are a dime a dozen right now also.

And yes, I do listen to Kevin almost every night.

Joe: Why not the M2 platform? BTW, is your engine the Mercedes with sleeves? I envy your power and gearing. Mine falls into the 'rolls kenardly' category.

Sorry, I am NOT an engine buff and don't understand a lot about them, like "sleeves". The M2 frame is just too light as are some of the componets. A Class 8 is much "stronger" all around. Fewer rattles, etc.

 

[usafk9]

Just a start, Moose.

Definitely not new for me.....I don't think ever.

My reasons for a class 8: Easier to get work done on it, Speedco's have the filters, most places have the parts, if I want to stretch the sleeper, I'm not trying to raise the roof on the cab (feel free to chime in, Joe), more cajones pulling a load (I've done 13,505# with my 260-horse - she did it, but let me know she didn't like it).

Generally more room, I guess.

Why not? I'm looking for any reasons, pro or con.

Thanks again.

AJ

 

[moose]

Speedco's have the filters, most places have the parts,

AJ

Hmmmm
HHmmmm....

I see a by pass filter on your horizon ....


no Speedco , no breakdowns...

 

[usafk9]

Sorry, Joe.

Some of the Mercedes engines (and yours) have a cast iron sleeve that is replaceable when overhauling due to out-of-round cylinders (bad seal, or too much clearance between rings and cylinder walls - crucial for compression in a diesel motor). The MBE 900's do not have these sleeves. To my knowledge, they are not rebuildable.

I reserve the right to be wrong, though. Haven't met my quota yet for the year.

 

[layoutshooter]

I ALWAYS exceed my QUOTA for screw ups!! I do know that this engine is able to be re-built. The M2 frame is the problem. The engine is STRONG, good MPG. The Tranny and rear end are fine.
Too light on the axles in the front. LOT's of rattles etc. Cheap plastic ever where. etc etc.

 

[usafk9]

I listen to Kevin fairly religiously. As I am obsessive about our truck's maintenance, I believe I will be on our 'new' truck as well.

If I am reading him right, Kevin advocates doing just what I am talking about....buying a used one, even if I have to do an in-frame, it's cheaper than financing a new or newer one. I have little faith in manufacturer's warranties, so a quick trip to a dyno would be in order before I buy. Kevin also says 'hooey' to CARB, as there are a bazillion trucks that are in and go into/out of California that have to be grandfathered. That does not worry me one bit.

Paid off fairly quickly is not in my game plan. Either we buy with cash, or we don't buy....period. I did it the other way before, and it it didn't turn out so well. Did I mention that I'm a truck driver now? We bought our truck on a gamble, and it has turned out wonderfully.......but I don't think we'll do it that way again.

As always, we appreciate and value your views.

AJ

FCC might have your fuel taxes set at 10.28 but the FSC is paid on 9 mpg. There appears to be a huge glut of used trucks or repo's on the market right now. If you can pick up a class 7 for a song and you do the preliminary steps to make sure you are buying a sound truck for it. If the truck is cheap enough you can get it paid for pretty quickly and be saving for the 2010 technology which you will need in the future to get into California and the other states that looks like they will be tag a longs. Your idea of using the lift axle is a good one and one that we will use on our next truck.

When you are looking remember CARB is out there and will happen and be as prepared as you can be. If you go with the class 8 stretch the frame and put a big sleeper on it can you get out of the truck and get into a CARB compliant truck easily and cheaply?

One of our greatest concerns is no break downs and no service failures. Any truck can breakdown any time but we try to do anything within our power to keep this from happening.

There is also CSA 2010 hanging out there on the horizon and the driver part of CSA 2010 will start being implemented in 2011. We are constantly looking to the future and trying to make sure our next truck will last as long as possible and be as versatile as possible.

Even trying to do everything right we still feel as if it is a crap shoot in the dark!

Sounds like you guys are also trying to do everything right!

 

[LDB]

I bought Sterlings, starting with the class 7 and then only class 8. The class 7 had the small MBE at 300hp with a 6sp. It would get around 9mpg. The first class 8 had a C9 with the 6sp. It would get 8mpg. The last class 8 I drove had the big MBE with the 10sp. It would get 10mpg. I also had one KW classic with an ISX Smarttorque 450/475 engine and an 18sp. It would get 8mpg. Those figures were running 60-62mph. There wasn't any advantage to going faster.

 

[sweetbillebob]

We are running an 05 FTL with a MBE 4000 set at 415HP. It is a full 40' with 100" sleeper, LG, Lift Axle, Reefer. It weighs in just under 32,500 empty/wet. We run 60/62 and get 10.5 with a light load and axle up, 9.5 with 5000# load and axle down. We run low rolling resistant tires, Pitt/Power muffler, Turbo 3000-D. I also have Balance Masters and Tru Balance on each axle. We just put on an OPS-Eco bypass filter and will be switching to Amsoil Synthetic over X-Mas. Air Tabs are also in the trucks future. (Yes, I listen to Kevin too.) I also use 1/2 container of "Meaner Cleaner" each time I fill up (average 150 gallons). Not sure if that helps enough to justify cost, but I only change fuel filters every 40K miles now and if you look in my tanks with a flashlight, they are clean, clean, clean. Hopefully my fuel/injector system will thank me in the long run!

 

[Dynamite 1]

curious as to what tranny and rear end gears you have slb. mine is a 05 112 also set @ 410/1550 w/the allison 6spd and 3:73 rears. low rolling resistance tires and centramatics up front, 96" slpr and a single axle. i weigh 23,460 full of fuel, all our stuff full water tank the wife and i and the dog. i had a life avg of 9.5 loaded and 9.8 empty. over thanksgiving i put on a pitt/power muffler and shortened up the exhaust 2' and removed all unecessary bends in the exhaust and only have one 90 in the system. been out running since then and have been avg. 10/ 10.1 loaded and 10.6 empty both these before and after avg are @ 66/67 mph @ 1300 rpm that is the sweet spot for my setup. used to be 65 but went from metric 22.5 to 11R22.5 and it threw the speed off about 1-2 mph over the shorter metric 22.5s. i use a combination of howes meaner once a month and power svc. about every 4th fill up. i am really impressed w/the fuel mileage gain. also i have noticed a small reduction in operating temp and a small increase in oil pressure. throttle response and turbo spool up also seem to feel better. dont know what i will persue next but i am definatly going to play around. really interested in getting the egr shut down and kevin is working on that w/one of his trks. w/the mercedes.

 

[usafk9]

TNT & Billebob-

Those are phenomenal numbers, IMHO.


Guess there's no reason I can't have power and fuel economy.

The guy I referred to in the original post seemed pretty happy with his 8 mpg. No way in hell for me.

 

[sweetbillebob]

I am also running a CL112, with the Eaton 10 Speed Autoshift. Not sure on the rears. Run about 1200 at 60 MPH. I also correct for the odometer, Freightliners usually run low, (reports less miles than actual. I use my GPS to make the correction. It goes like this. Pull into a rest area when you can make a run without exiting for at least 200 miles. Stop the truck right when the 10ths click over. Make this your GPS start. Stop at another rest area at least 200 miles down the road. Stop right when the 10ths click over. Make this your GPS stop. Compare the miles traveled on your odometer to the miles the GPS says. The GPS is accurate, the odometer is not. And if yours is like mine, you are going farther than the odometer is reportiing.

Also, I use Meaner Cleaner ever tank full at about the recommended dosage.

 

[Dabus1952]

I am just curious where all these repoed trucks are located.Is there a Clearing house that sells them ? Little off subject but I saw the comment about buying used and great deals. Thanks for your Imput

 

[Mdbtyhtr]

Just some technical input for the unfamiliar, and I am sure the familiar will correct me if I am wrong

Replaceable liners refer to the cylinder liners, and are replaced with pistons, rings and rod bearings during in frame and out of frame overhauls. These are often referred to as Liner Kits.

Engines that have liners that are not replaceable are called "Parent Bore" blocks, which simply means that the pistons ride in a cylinder machined out of the block or in the case of Bi-Metallic applications, pressed in, interference fit steel liners, which are not easily replaced and definitely not done as an in-frame overhaul. In the old days, we used an arch welder to weld a bead up the side of the liner and another 180 degrees opposite the first weld. This would generally shrink the pressed in liner sleeve enough to be able to remove it. We would freeze the replacement and press it in as fast as possible and as it thawed out, it would expand into place. If you had a problem during the process, you were in trouble!

The benefit of a wet liner engine is that an issue in a single cylinder did not require a complete overhaul. If you had an injector fail and over/under fuel a cylinder, resulting in piston seizure or rapid wear due to fuel dilution of the oil, you could replace the offending cylinder only and you were back on the road.

Scott

 

[usafk9]

Thanks for that, md.

We refer to our cylinder liner-less engine as a future boat anchor. A sixteen thousand dollar boat anchor.