Turning motor down?

JustAddRubber

Expert Expediter
I was look at a truck with a ISX-450 in it, how far can that be turned down in the computer to, get better gas milesage? but still run the hills good?

GJ
 

Glen Rice

Veteran Expediter
Your best bet would be to contact your local Cummins Engine shop and ask them. Depending on your set up you may not want to turn it down! There are plenty of us out there with "BIG" horsepower and running the gear fast run slow program, and getting great fuel economy and still have all the power to get over the Mountains ASAP!! I personally love big horses!! Best of luck and keep us posted what you decide, and let us hear about your real world fuel economy numbers.
 

JustAddRubber

Expert Expediter
Glen

I found were Weave turn his down, "My S60 is 470 HP, but I had the computer set to derate it to 360 HP, which is still more than ample with my 10 speed. Can run triple digits if one is stupid enough to do so."
I was hoping to get better mileage with it turn down.

GJ
 

davekc

Senior Moderator
Staff member
Fleet Owner
I agree with Glen. I would call cummins on this as the ISX engine may be set up different. With the EGR system, changing the computer may effect performance in places you don't want. Weave is right in doing what he did on his engine, but with the new computers and engines,it could be different.
 

x06col

Veteran Expediter
Charter Member
Retired Expediter
US Army
I guess my question is - If you don't have the truck on the road, and don't know if it's a 12 mpg truck or 6 mpg truck, why distress over it now?? I'd suggest you take it for a test drive of about a hundred miles, set the dash to 0 and see what it gets. Then you have a little data to research with.
 
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