Noticeable Mileage Increase in 06

[COBRAJET]

I replaced the cat and factory muffler with 4" pipe and a MBRP resonator. I also switched to synthetic oil at the same time. This was at 12K miles. I just turned 15K and have averaged 19. 3mpg on the highway at 70mph since the change. Today the truck averaged 19. 8 on a drive from Dallas to Laredo... about 420 miles with very light winds. I am a very light footed driver on the freeway. All mileage calculated by hand although the trip is usually very close. The truck was averaging 18. 5 before the changes. The exhaust is a lot louder under load, but not very noticeable at empty unloaded highway speeds. Not sure how to attribute the improvement between the changes, but it is definitely there.

 

[Cummins Cowboy]

I think part of it may be break in I have noticed my '06 is doing better on every tank, and I am still shy of 6k. I hope the trend continues

 

[natemcclure517]

I got a 2006 3500 drw 2wd with 3750 miles. I am getting around 15 mpg does that seem about right? I was hoping for more.

 

[BHolm]

The harder you work it, the less time it takes to get it broken in. With occasional heavy towing, and a fair amount of light towing it has taken me about 25-30k miles to get my trucks up to 17-18mpg. I haven't had the "600" version much longer than that yet to see if it creeps up on 20, but I kind of doubt it.

 

[BHaden]

I got a 2006 3500 drw 2wd with 3750 miles. I am getting around 15 mpg does that seem about right? I was hoping for more.

YUP. I have the same truck as you (Mines a 6 sp) with 5500 and I've been in the 15. 5 range pretty much all the time until recently, when it pulled a 16. 0.

On the freeway it will get into the 19+ range on the readout, which is consistently around 2 mpg high (!?). I'll have a better idea how it's doing in 2 weeks. I'm about to embark on a near 4000 mile trip from San Diego to Topeka

and back with 3 friends and a 6000lb trailer to the SCCA Solo Nationals. That should contribute a lot toward breaking it in. Everyone on this board with experience says the same thing; mileage and working them hard brings the mpg up. It appears they know what they are saying.

 

[WMcGuire]

I got a 2006 3500 drw 2wd with 3750 miles. I am getting around 15 mpg does that seem about right? I was hoping for more.

IMHO 15 mpg sounds about right if you have 4. 10 gears, if you have 3. 73 and all else being equal you should get around 18 if you keep the speed down around 55, if you consistently drive over 65 you are lucky to get 15.

 

[BHolm]

IMHO 15 mpg sounds about right if you have 4. 10 gears, if you have 3. 73 and all else being equal you should get around 18 if you keep the speed down around 55, if you consistently drive over 65 you are lucky to get 15.

I played around with rpm and cruise speeds last time I had to drive across Nebraska..... plenty of time to ponder this stuff on that drive On my truck ('06 Mega 4x4 48re 3. 73) once you go beyond 2100 rpm the milage really starts to suffer on this highway. 2000 rpm is decent, 2200 starts to hurt. I was using my overhead, which btw was about on for a 3000 mile round trip. Sometimes it was a little high, sometimes a little low. For comparison purposes though, I would lose 2-3 mpg going from cruising at 2000 to cruising at 2200, above that, it continues to drop The 3. 73 autos have an advantage here with a little taller OD gear, I also run a little taller tire. So grossing at 14,900 pulling a triple axle flatbed gooseneck empty I could get mid 13's running 70 and it dropped to mid 11's running 75. With a manual and 4. 10s you probably have to stick near 60-65

 

[natemcclure517]

Is there any after market parts that could help dramatically change mpg. For example FASS, air intake, exhaust, chip. If so which kind.

 

[wcjp]

Recent article in Diesel Power changed the camshaft on an 05'. They saw minor power bump and 2. 1mpg improvement.