sweetwaterguy

After reading many threads on fuel economy numbers all over the map, it seems there must be other reasons for poor fuel economy besides driving habits and winter fuel. Perhaps those who have advanced knowlege of diesels might step forward and explore other factors for this forum. What other factors could cause similar vehicles and similar driving behavior to get such dissimilar fuel economy numbers?

Cmullen

I see an differance of a mpg or 2 just depending on where i fill-up. also I religiously put stanadyne performance and lubricity in my fuel. Another factor maybe the differance in pump sensitivity and whether people always filler up to the brim or if they stop when it clicks off.
an d last ly people who seems to get the better mileage seem and I only say seem to be the more experienced at driving diesels.

So the experience factor

Just my two penneth

silver_goat

fuel does have a lot to due with it. I have seen anywhere from .5 to 2 mpg difference depending on where I fill up. Been using Murphy USA (Walmart) fuel lately because of price. It gets lots of traffic and seems to be consistant after using it for several months.

Foxborough

Before buying my truck in December, I reasearched this sight and figured 13-14 MPG city and 17 MPG hwy. After 2 months & 3200 miles it is exactly as these guys said. My average since new is 14.7 mpg (hand calc). I am happy with that. If I get 2 more mpg better after break in, even better. The variations I believe are from the driver habits and location. I thing the biggie is the truck changes. Most complaints I see tend to come from people with tire changes, lift kits. That has got to make a big difference. Tires roll different and a higher truck has more resistance.
Just my belief.

Dynocon

This is an interesting question. I think that there would need to be a tremendous amount of data collected to get solid results.
Some of the info would be the basics stuff, auto/manual, rear end, outside temperatures and so on, but you also need to look at tires, type and tread pattern since there is a difference rolling resistance for each not to mention the pressure.
Lubricants, engine, trans, diff, weight of truck with stuff and so on.
Aerodynamice, who has a tool box, bug shield, mud flaps, cover or cap.
The list goes on and on. Big job.

I think most people agree that in general the onlt things that have changed over the last several years, except the MPG, is the engines and the emissions stuff, third injection events, cat converters.

I to would like to get a few more miles per gallon.
Does anyone have good MPG data before a specific mod, then after?

I had a guy tell me the other day that he increased his MPG by 3 by installing AFE kit and upsizing his exhaust, I was drooling, then I asked was it hand calculated and I saw the deer in headlights look, why would I calculate it when the overhead shows me. This data was tossed in the cylindrical file.

robert chilton

I honestly think alot of the MPG loss is in the computer programing. Both times my truck got really good MPG was driving in the mountains Higher elevations, raised RPMs and higher boost just shouldnt add up to better MPG. I think something is wrong with either the programming or the sensors calibration limits. Granted my 12v is 2000lbs lighter but I get run it at 2000 RPMS all day long and get better milage with less smoke. My 600 lays a cloud every time I get on the go pedal (not floored) where the 12 valve puffs and goes with similiar power output at WOT. The later truck isnt even tuned yet either.