What Motor?

I noticed that, the tires designed for "fuel mileage" cost more and have extremely shallow tread. Kinda like 22.5's sure there cheaper but they wear out faster (rotate like 31 more revolutions per mile) and can't carry the same load. So while you may gain .3mpg you didn't save any money. I guess it just makes people feel better if they believe their saving money. Turbo3000 comes to mind.

 

Sportster,

I appreciate the information. Has anyone had the pittsburg powerbox in their ISX? If so, what were the results?

KH

 

That is exactly the way it works txviking. They just cant leave anything alone.

 

PaulE,

Thats how messed up those discussions about mpg are.
There are 2 groups of people driving trucks.

There are real professionals, good ole truckers who cant get 6 mpg because they also know it takes YEARS of driving that truck to get really into black and mpg is rather meaningless. At least it used to be

Then there is new breed of supermorons, people who just entered the trucking, bought some piece of $ hit truck, installed Turbo3000 and get 7.9 mpg readout from the dash.

Then we have parasites over the radio and so-called trucking publications who work with makers of all those things you dont need, but if one is naive and have no idea how $ hit works - they will sell whatever they want to those idiots.

So, my comment you commented on was NOT directed to one of those groups. Get it?

 

I was going to say something but never mind.

 

we had our first 2 geared wrong. We were running 1550 rpm at 65mph. Our last 2 have us at 1425 rpm at 65 mph. Big difference in mpg. These new DD15s are built to run at very low rpm....and not built to run at high rpm. Our worst runs have been 6.1 to 6.3. Amazing what a difference 100 rpm can make.

 

That is low for Detroit. But I guess that is the new way. Lot more torque way down. Maybe some day I'll get to be a high roller like you guys with your new toys.

 

Ours only had 3.21's in it with a 13 at 72 mph we were turning bout 1450. I'm thinkin its a fluke the guy has 3 more and they are claiming mid 6's as well. The last run we made in to Cali. and back we had a round avg of 5.9 which i thought was ok considering it only shut off about 3 or 4 hrs the whole week. It was getting better just needed to get a lil freeier I think. Plus we drove the C R A P out of it lol