* Class 8's - Fuel Economy *

Tom Robertson · Dec 30, 2004

We are considering class 8’s as our new standard expedited truck. We are trying to determine which manufacturer offers the best fuel economy. I have some information from a very reliable source of a Kenworth T-600 set up that achieves 12.8 mpg’s.
I would appreciate hearing from owners presently using class 8’s, set up with high roof condos and the fuel economy you are presently getting. I would also like to know the specifics on engine size, transmission and rear end ratios.
I believe the T-600 is a 13 speed manual transmission... does anyone have an automatic that rivals or betters the 12.8 mpg?

terryandrene · Dec 30, 2004

>does anyone have an automatic that rivals or betters the
>12.8 mpg?

My cab-over Chev 3500 automatic gets 15 mpg...SORRY, I can't help myself:7 :7

geo · Dec 30, 2004

when i had my star was getting about 11/12 mpg with eaton 10 spd sel
auto shift with c10 but had help with tk7 from bnd
now with sprinter getting 19 to 35 with help of tk7 also depends
how hard wind is belowing and how heavy i'm load

Glen Rice · Dec 30, 2004

I had a Volvo engined VNL42 Straight truck that had the Eaton auto-shift 10 speed with 3;55 rears and tall 11R 22.5 steer tires all the way around. Horsepower was 425 and the empty weight was 32,000 lbs. My wife would consistantly get 11.5 or better for fuel mileage, I could only muster 10 plus. Go figure? Big horsepower geared for big mile an hour has always been a winning combo! By the way, steer tires all the way around was good for 1/2 mile per gallon.

jack licata · Jan 3, 2005

Tom,
I think you need to consider the engine manufacturer,displacement, and HP, in addition to the truck coefficient to drag ratio.

Have you ever heard of this new inline add on called Turbo 3000.
They are claiming a minimum of 10% increase in fuel economy.

Does anyone have any experience with it?

Jack

Tom Robertson · Jan 3, 2005

Jack

I've heard about it, but on another post asking for information on money saving devices... no one responded about the Turbo 3000 or about the Amsoil by pass filter system...
I retract my statement about Amsoil... most felt that there is no substitution for fresh oil changes... however no one appears to be using the system.
I've purchased so many trucks and spec'd them as advised by the dealers only to find out they did not produce the mpg's promised that I thought perhaps someone could provide the best set up they have achieved...
I have 4 FL M2's presently getting 10-11 mpgs on the class 7 set up... to my knowledge that's about as good as it gets.
I would like to hear about someones actual use of the Turbo 3000 as well.

rode2rouen · Jan 3, 2005

I just did a "google" for Turbo 3000 and it came up with an air dryer and a marine bilge fan as the major matches....
I don't really think either would contribute too much towards raising fuel economy, but having dry air in the brake system is certainly a good thing for trucks.

Rex

RichM · Jan 3, 2005

Put on the Dave Nemo show in the AM on XM.They advertise the turbo 3000.

rode2rouen · Jan 3, 2005

Rich,

I've tried to get the Nemo show, but it doesn't come in on my SatRad, Siriusly!

Ok, I just found the "Turbo 3000D" via a link on Dave Nemo's web site.
I read through all of the FAQ and flak and it is "my opinion" that the only benefit you will get from this device is a lighter wallet! This will be offset by the weight gain (loss of load capacity) as the Turbo 3000D weighs more than the 2 C notes you paid for the device!

Snake Oil....Buyer Beware!!

Rex

davekc · Jan 3, 2005

Remember that it is the drive train more than the specific truck that will deliver the desired fuel economy.
Steer tires all around this time of year could prove interesting in the snow. Might be fun though

Davekc

Weave · Jan 4, 2005

My class 8 Columbia can do 12-13 MPG with it's 360 HP Detroit, 10 speed manual. When not running the A/C, with tailwinds, and no idling. Average MPG is around 10 in normal operation. No complaints from me, as my FL70 only averaged the same, with 230 HP Cummins and a 6 speed. The advantages you get from class 8 trucks are the much greater power and longer life without much if any sacrifice in MPG, plus greater resale value and generally higher overall quality. You add up all the factors, and the class 8 platform almost always comes out ahead during the period of ownership. Maybe not a direct answer to your question Tom

but I know those are the reasons why myself and all of the small fleet owners I know have gone to the class 8's. Just much more driver/owner satisfaction. I know the MBE900 engine only has a rated service life of 500k miles. Those miles will rack up quick on an expediter truck, then you might be into replacing a $15k engine, or trying to sell a truck that will be considered worn out and basically worthless. With the million mile projected lifespan of a class 8, those type of worries just don't come around as fast. One fleet owner I know is still using the 1996 FLD112's he had when I started expediting in 1998 as his flagship trucks.
Looking beyond just MPG, for trucks running heavy highway miles, best to use class 8 highway trucks. However, I still wouldn't try those steer tires as drives in a Buffalo winter, better keep that plan limited to driving Dixie!
-Weave-

BigRed32771 · Jan 5, 2005

Weave, is your Columbia set up with a factory sleeper or do you have a custom sleeper unit? If custom, what specs and who did the work for you? I'm already planning my second truck, and I haven't even picked up my first yet ('01 FL Century w/ autoshift and factory condo).

Tennesseahawk · Jan 5, 2005

Tom... my co-driver is an amsoil rep. I'm leary of changing over to a system that is very hard to find reps. Otherwise, the money and time saved on the oilchanges would sell me if I bought a newer unit. What good is it if there's no oil? LOL

Weave · Jan 15, 2005

Sorry I didn't get back to this sooner.. remember I drive for a living

My Columbia just has the 70" integral sleeper. It's very nice, and I work hard so I sleep like a kitten in it. Luxury solo motel room.

Money and time saved on oil changes? Maybe for you Hawk, not for me.
Amsoil, Wonder filters, synthetic oil, Slick 50, oil analysis? Great stuff. I have manuals for just about EVERY diesel engine manufactured (My hobby;-) )
NONE of these products or services should be used to extend oil change intervals. Read the manufacturers manuals. I for one would never take a chance on a snake oil company "rep" who is your co-driver. Sorry buddy, not in my $15k engine.
-Weave-

ATeam · Jan 15, 2005

You add up all the factors, and the class 8
>platform almost always comes out ahead during the period of
>ownership.

I agree. For that reason we (wife and me) decided on Class 8 early in our truck spec'ing process. That also meant that I aquired little knowledge about Class 7 platforms when researching trucks. Because of our early Class 8 decision, we had no need to do a Class 7/Class 8 comparison. Weave mentioned adding up all the factors. If anyone out there has ever done a detailed Class 7/Class 8 comparison I'd love to hear about it out of simple curiosity.

For example, putting driver comfort aside as a consideration, and if you spec'ed out a Kenworth T-300 and a T-800 with the same custom-built sleeper and all other features identical, and if you optimized the engine and gearing choices for each truck, what would the cost differences be on the purchase date, and what would the operating expense differences be over say five years and 500,000 miles, and over ten years and one million miles? Include engine rebuild and truck replacement costs, if any, in the analysis. Assume driver skills are average, all manufacturer-recommended maintenance is done on schedule, and no aftermarket devices are added unless the identical device is added to each truck.

davekc · Jan 16, 2005

You add up all the factors, and the class 8
>platform almost always comes out ahead during the period of
>ownership.

I am not quite on the same page with this. There were figures presented several months ago that had indicated the numbers between the two were very simular. The class 8 wins out when factored at a 5 year cycle but costs considerably more. At the five year period if you replace the class 7, you have a newer truck with the lastest features as well as a warranty. Other non warranted items like batteries, hoses, and that long list of items not covered have to be accounted for somewhere. And if you are a fleet owner, it is worse. Who wants to drive an 8 or 9 year old truck? Probably not many.
If you are doing this over the longhaul, you have to look at all the factors. You have to consider as well that most stock class 8 trucks have smaller sleepers. Most teams want something larger.
Davekc

Weave · Jan 16, 2005

I have been trying to do a bean counting comparison between the figures I had with my class 7 FL70 and my current class 8 CL120. I have all the numbers, but as both of these trucks were purchased used with different mileage and in different conditions when I started out with each of them, my case would not make a good detailed cost analysis for a fleet owner or ? It might be something requiring a direct comparison, side by side, brand new trucks running the same miles under the same conditions.

I did state on the other thread that the fuel mileage between the FL70 and the Columbia are just about the same. But the Columbia could easily leave the FL70 or probably any class 7 unit on the market in a wake of dust. It is a nice feeling to know the engine never struggles and can move the truck up the steepest grades fully loaded at speed like it's a sack of feathers. Even though one truck I am considering for the next ride could be a class 7 Pete 335, I'm not sure I could go back to something with a little engine that spins up all those RPM's at speed. Having gone from a mule to a racehorse, for my own use I still want the racehorse even if it might cost a bit more, but in my cases I haven't noticed that it does.

I'm probably still not on the same page with you Dave, but let it be known I'm sort of a Tim Allen "MORE POWER" type, provided the stakes aren't too high to own it:7
-Weave-

davekc · Jan 17, 2005

Weave
I like the new Petes. I read somewhere during the mid year you will be able to go to some larger engine sizes. I know they will take a cat 330 but not sure on how much larger.
You are correct, as an individual can look at these comparisons much differently than a fleet owner.
Davekc

Weave · Jan 18, 2005

So far the only engine offerings for the Pete 335 are the same ones for the old 330, the CAT C7 and Cummins ISC 8.3. CAT up to 330 HP, Cummins 315 HP. They are eking a lot of HP out of those small displacement engines by adding beefier turbos and larger injectors, and essentially maxing them to the limits of their mechanical abilities. If Pete/KW could get a new C9 into the 335, I'd feel a little safer with it on the highway. Paccar chassis and cabs are awesome quality, and along with power that is something I enjoy in a truck or personal vehicle also, something I haven't experienced with Freightliner yet.
-Weave-