Crappy fuel economy? What gives?

[TFucili]

... So, how much advance is needed for better returns?

I was told by a vendor who is highly respected on these boards that peak fuel efficiency comes at nine degrees advance.

 

[Rdunn]

my understanding is that 04. 5 has a pre injection, a main injection, and a post injection of fuel, sure this makes them quiet and cleaner burning but this has to hurt fuel economy; does anybody make a box to have a main fuel injection only? I LIKE DIESELS NOISY AND GREAT ON MILEAGE Oo.



04. 5 2500 sport laramie 6spd. QC 4wd

 

[DPKetchum]

In the short version. NO

 

[Msilbernagel]

My 'sub gets 18 in mixed city/suburban driving, and 18-19 on the freeways at 70-75. I suppose it might do better if I hit the highway and held 55 (w/4. 10s) since that gets it in the 1800 RPM range (60 is 2k in 6th).



I'm hoping a few degrees of advance will pull the average up over 19. With a 40 gallon tank, it adds up!



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