Fuel Mileage

[Jarrett]

Thinking About Trading A 3500 Drw 6-speed Mega Cab For A 2500 Ext. Cab Srw Automatic... . was Wondering If Anyone Knows If Fuel Mileage Will Be Better. The Fuel Mileage Sucks On The Mega Cab

 

[JFaughn]

There are a lot of varyables in your question .
It seems that the ULS fuel is a problem with millage , but the 2 biggest seem to be the gear ratio [ no yrs in your ? , but the mega cab implies newer ] 3:55 - 4:10 in older , 3:73 - 4:10 newer , the lower number giving the better maillage but less gearing for pulling , so your stuck without changing the gears , lots of money with a 4x4 , maybe $ 2,000 + ,
Then how you drive .
I would think the biggest differance in the 2 trucks in your question is the duals , the lack of should make a 1-2 mpg all els being the same , the trans opption I would guess to be the least diff.
If your looking at trading [ that cost $$$ ] you could spend the same $$$ to change gears to 3:55s or lower # , then a few dollars to mods for more power to make up for the gearing .

 

[Jarrett]

Both Trucks Are O6's. The Mega Cab Has 3. 73 Gears With 235 Tires At 70 Mph I'm Running 2400 To 2600 Rpms, Averaging 13 Mpg.

 

[idlap]

Something Isn't Right

My '07 2500 4x4 has 3. 73s and at 70mph the tach reads 1900rpm.

I've haven't made dedicated highway run yet but with 60/40 highway/city driving I get 16-17 mpg depending on my driving style.

 

[DBentley]

You didnt say how many miles are on your mega.

Im sure we will see a increase in mpg at 20 or 30k. (I hope cause at 2600 my milage is 15ish around town driving like a old lady)

 

[tgrfan2]

Both Trucks Are O6's. The Mega Cab Has 3. 73 Gears With 235 Tires At 70 Mph I'm Running 2400 To 2600 Rpms, Averaging 13 Mpg.

My 2006 turns between 2000 and 2100 at 70. It gets 15-16 mixed driving and 17+ at 75mph on the I. That is comparable to the mileage I got with a 2000 2500 SO 47re with 4. 10s. I just had it reflashed Friday and don't know how that will turn out yet. The last truck I had reflashed was a 98 GMC 5. 7 and they managed to kill the power and mileage!

 

[Jarrett]

Ihad 16000 Miles On It Its Not Mine Anymore . Traded It For A New 2006 2500 Auto. my 2002 And My 2006 Were Both 6speed I Hope This Auto Will Hold Up As Well. i Like The Why It Feels.