Wanting better MPG

I have found "the more HP the better the MPGs"
Its all down to the top 6 inches and the right foot

 

6.5 is respectable. You want more?

 

go to detroit thread .DD14 can help you. there are things that can be done.

 

go to a single drive axle, less weight, less gears, less rolling resistance

 

Low pro tires or super singles.

Fewer gears.

Direct drive with tall gears.

 

I think there are better ways to get a little more feul economy that dereating your engine.I have gotten in the middle 6's at 70-80,000lbs. with twice that hp.Not knowing much about your driveline I would suggest making sure your air intake system is good,use an air restriction gauge(not an indicator).If that is good then make sure your CAC is not leaking(connecter hoses to).If all that is good check your feul pressure,it should be no more than 65psi. no load at 1800rpm.If it needs to be adjusted just replace or drill out the restrictor fitting on the back of the head which is .80 from the factory .90-.105 should get you close but check it with a gauge.The next thing is to make sure your overhead(rockers and injectors)is set correctly.If you are using this truck mostly during good weather I would also have ribbed type (steer tires) drive tires,this helps alot.If you do not mind a little more exhaust sound then you should consider a lower back pressure muffler,this frees up the engine a bit it will give a few 10ths. of mpg. It's a start!

 

Good post above. Also, keep your foot off the throttle pedal. Use progressive shifting. When starting off, just get the truck rolling before going to the next gear.

You don't need to touch the govenor in any gear except maybe 9th with no more load than you are pulling.

Always ease down on the throttle. When stopping, back off the throttle and ease up to stops.

A trained foot can always get better fuel mileage than the cruise in rolling terrain. Use cruise on flat land.

In hilly areas, ease into the throttle before the uphill grade to get the turbo spooled up, ease out of the throttle just before the top, even if you lose a few MPH. Get completely out of the throttle at the top of the hill and let gravity get the truck up to speed.

These few tips can show an increase of .75 to over 1 MPG easy.

 

DD14, My 03 12.7 has the small turbo, and I have been told a bigger turbo will cause less back pressure. ??? Could you suggest Make/model? I have allready put on no-baffle muffler, checked charge air cooler, run rack. This week-end the restrictor fitting and mechanicle fuel pressure gauge. Thanks.

Dave