What's the big deal with keeping it below 2000rpms? Just curious if that is important to do.

 

The Cummins starts sucking down fuel above 2000rpm.

 

Ah, that's why my MPG went down this morning! Well I guess I need to slow down.

 

I'm averaging 15.93 MPG since new with only 25,800 miles on it.
A mix of 30/70 open roads/ traffic. All hand calculated

Michael

 

I made an Excel spreadsheet and keep it on my Palm Pilot I keep in the truck, and log every fill- up all 48 of them so far. Hand calculating is the only true way to see what your doing. The graph it spits out shows thats it has been getting better as it has got broken in.


Michael

 

That's nice, keep it up and you'll be the go to guy on this info.

That data should be logged somewhere public

 

I get my best mileage is between 55 and 60 MPH and when I go up to 1800 RPM's or above my mileage startes to drop.

 

I just got 17.33 highway trip doing 75-85mph with my 315s & 4.10s if you can keep your foot out of it and stay below 2000rpms you can do better I've seen 19s when I do 70-75mph

 

Heh, that's pretty good because I got 17.33 on my first real tank. My overhead said 19.1. I don't know which to believe since there could be a variance from the pump not being accurate or not shutting off soon enough.

That's about 20% spirited city driving and 80% hwy cruising at about 2000rpms around 72mph. And the truck had around 500 miles on it.


Thanks for the help.