The "Sweet Spot" (best MPG)

My previous truck had an 01 Series 60. I complained about poor fuel economy and the Detroit dealer programmed in some different injector codes. "73" was the code, IIRC. At any rate, the readout showed a 15% increase in MPG while my tankful to tankful measurement showed a decrease of 10%.

Just saying.

 

Sounds like one of those castration programs that carriers are using these days. Cummins started screwing with our fleet a couple of months ago. My previous truck was a test bed for their new program. The program cut boost by 50% at 62mph so that you were struggling to get up to speed. It also introduced a 4 second delay in our jakes in an effort to "stop people from overusing them." I'm sure it changed other things like fueling and whatnot. Even though they swear up and down that they get better mpg's, my provious truck went from 6.8 average to 5.2 average.

 

Actually the power increased significantly with the different code.

 

And running slower can cost you 50 - 60 miles a day and get you to a truckstop an hour later to find it full . That's silly to me .
If you are going to sit 2 or 3 hours to wait to get loaded or unloaded I get taking your time makes sense . That's not the way we roll . We always have the full 11 hour drive time available and do 2 day turns that couldn't be done running 60 mph . I just ran a 3 day drop and hook from KY to Houston and back . Day's mileages were 625 , 637 , and 652 . Driver pay was $900 .

 

All states should have signs like VA telling trucks to stay out of the left lane if not going the speed limit .

 

Today, the sweet spot is about 1000 miles south of here.

 

I see between 6.5 to 7mpg with an 600 ISX cummins, I usually run the speed limit.

 

My sweet spot is in the hammer lane.

 

if your sweet spot is 15 to 1600 rpm to keep egt down .id suspect that you have a cac leak or plugged exhaust

 

I wonder if this thing has a sweet spot.