Nobody has written anything in this topic in a while, but I am looking for suggestions. I have an '06 cummins Quad cab 4wd, no lift just 315 M/T and the Superchip flashpaq. Right now the only way I am getting 18mpg is flat out on the highway. It drops to about 14.5-15 when I am running "errands." I am comfortable with 18 but I am actually averaging 16.5-17.5 between stop&go and flat out highway driving. Any suggestions on any upgrades or tips that don't cost much to improve fuel mileage?  

check what axle gears you have, theres a huge difference between 4.10s and 3.55s
higher load range tires can help a lot (3-5)mpg


First reply!!!!  

If you don't tow that much, running a taller axle ratio might not be a bad idea, but if you do tow, I wouldn't go much taller than about a 3.73.  

mine has 4.10 gears at 65 to 70 its 2000 rpms going to 315 next running around town 18.5 going on highway at 70 to 75 mph 16 mpg and lower  

I have a dodge 1500 pu with the 5.9 engine. I get only around 9-10 mile's to a gal. an the most maybe 12 mile's, can any one out there tell me why I can't get better gas mileage with only 32000 miles on the engine, its a 2001.  Thank You.  

1500 with the 5.9? You must be talking about the gasser V8. This is a diesel forum. The ChryCo 360s (5.9) were notorious gas hogs. Make sure your tires are properly inflated, buy a tonneau if you don't already have one. Maybe have your injectors cleaned, or just throw a bottle or two of Techron in the tank.  

I get around 20mpg with my GM 6.5 around town and i have found that by airing your tires up 5 psi over will help but be carefull in wet weather or under a load. and also changing your oil at 2500 miles insted of 3000 will help too. keep your filters fresh and do not use fram for any reason they  are junk use K&N they cost more but all in all they will help your fuel millage. better parts is the kea.  

I have a 2004.5 cummins quad cab long bed. I was getting about 19-20 mpg with an intake. I bought the Quadzilla Mileage Max Module, $180 at XtremeDieselPower...I now get 22mpg...it was definitely a worth while investment with diesel prices at $4+ a gallon. Exhaust is soon to come and hopefully will help me gain a lil more. I also noticed a lil power pickup too, maybe 30 ft/lbs.  

Anyone getting more than 20 mpg with these trucks is doing pretty good, IMHO. I've got a little weenie Mazda Protege, and I average about 23 mpg, so if you're doing that good with about quadruple the power & torque I have, I gotta admit I'm a little jealous.    

Look in to HHO units or brown hydrogen helps about 15% or 20%  

I have an 06 2500 quadcab 4x4 ctd.  i get 19.3 city; 22.8 highway with 285 10 ply grapplers, k&n filter, and no muffler...