Gas Milage 4.8l With 3.73

[ndhonor]

I am thinking about upgrading my rear gear ratio from 3.23 to 3.73. I have the 4.8L V8 NBS CCSB

 

What gas mileage are you getting with 3.73? Even if you have the 5.3L or the 6.0L.

 

Thanks

[FREAKENHYE]

Depends, on the FWY on 65 with CC on averaged 23.9 MPG for 80+ miles.

 

07 New Body EXT CAB 5.3L, 3.73 gears, 20" rims, headers, exhaust, intake, 3 degrees advance timing, with TQM removed on 91 gas.

 

City is about 16-18 if i granny it.

[pm26]

I am thinking about upgrading my rear gear ratio from 3.23 to 3.73. I have the 4.8L V8 NBS CCSB

 

What gas mileage are you getting with 3.73? Even if you have the 5.3L or the 6.0L.

 

Thanks

 

What mileage are you getting right now with the 3.23 gears? When not hauling or towing, 3.73 gears will drop your mileage by 1-2 MPG.

[GatorFan]

Mine is not the CC but I do have 3.73 gears with my 4.8L. Running 33" off road tires I still get 22 MPG on the road (driving 75+ MPH) and about 19 in the city. I have done some mods so that probably (maybe) helped with the MPG if I could keep my foot out of it.

[pm26]

Running 33" off road tires I still get 22 MPG on the road (driving 75+ MPH) and about 19 in the city.

 

Only with the 75 MPH + tailwind.

[ujtruck]

avg 17 mpg local and freeway(highway) driving, I didn't not see 20 recently due to winter may be...

[bassadict69]

I have the 4.8 with 3.73 running 285's & get about 13mpg mix between city & highway. But, this is on an unadjusted speedo for the difference with the tire size.

[papapump51]

5.3 engine 3/73 gears I get about 17 to 20 depends how much i romp on the gas - in FL where I am even city driving is almost highway so not alot of stop an go

[ken1mod]

I have never gotten less than 18 nor more than 19 in 4000 foot altitude mixed city (mostly short trips) and highway driving. I squeak the tires daily but I do know how to coast up to stoplights. I use regular quality oils and cheapest gas. Truck runs sweetly with 130 thousand miles on her. No clicks or noises from engine. I use valvoline 10-40. Also my mileage is the same in summer with a/c on as winter with it off. I get over 400 miles between fill ups. I tried synthetic oil once and my leaktight truck and Acura started leaking like an old Detroit diesel. Foolish me. Back to Valvoline which took me to 130k flawlessly and quietly.

 

The "driving ahead of the truck" is very important. Seeing that a light is red and getting off the gas is where mileage happens in city driving. I definitely recommend 3.73 gears on a 4.8 or 5.3 (I have a 5.3) unless very heavy towing is planned. Letting the engine turn a bit faster is not a bad thing and seems to have little effect on mileage plus, I believe higher tail gears are easier on the transmission because it is moving the power as rpm rather than torque.

 

Ken

[2004GMC1500CC]

I am thinking about upgrading my rear gear ratio from 3.23 to 3.73. I have the 4.8L V8 NBS CCSB

 

What gas mileage are you getting with 3.73? Even if you have the 5.3L or the 6.0L.

 

Thanks

 

I get about 14-15 in town and 18-19 on the road with my 04 5.3L 373 CC.

[Volucris]

O7 CC 4WD 4.8 3.73 everything stock, camper shell, crappy off brand 7-11 gas. - 17.6 mpg at the last fill up. It's 16 to 20 for me. Once I got 22, but that seems to have been a freak occurrence, unfortunately.

[strafingmoose]

Man, you guys from down south got great gas mileage comparing to us northern folks.

 

I understand why Americans buy more trucks and SUVs than us

[-Devil-]

i get on average 17 to 19 mpg per tank .. but i am running the 323's with a 4.8

[cerbomark]

Dont do it! I had a 07 CC NBS for 5K miles(with 4.8./3.23) and traded it in. It will down shift constantly under the slighest load , especially if you put 20 s on. I m was lucky to get 18 highway with that truck. My 6.0 can get 18 highway under 65-70MPH. At 55 I can get another MPG. Get a ecm tune if you didn t already, that will help. You really can t compare everyones MPGs like this, there are too many variables.

[unit731]

I have the 4.8 with 3.73 running 285's & get about 13mpg mix between city & highway. But, this is on an unadjusted speedo for the difference with the tire size.

 

 

I think this is a little more realistic.