RoflCopter726

I have an '07 NBS ext cab LT1 with AFM and 20" wheels. I've had it about a year and five months and I've put 31,000 miles on it. My DIC reads an AVERAGE of 16.6 MPG. Most of my driving is combined highway and city, 20 miles on the highway to and from college doing 55mph with cruise control. The AFM seems to help out also, i can usually go close to 430-460 miles per fill up, so thats anywhere from 16.5 to 17.6 mpg. On the highway i made it from Houma, Louisiana to Hot Springs, Arkansas in one fillup by the skin of my teeth, i had about four tenths of a gallon left in my tank when I got there. Approximately 519 miles with a 26 gallon tank, thats 19.96 Mpg (20). I put a bottle of fuel injector cleaner in my tank after every 3,000 mile oil change, check the air in my tires every time i fuel up and keep them all at 31-32 psi<(insert Obama joke here), and drive as much as possible on cruise so the AFM kicks in as much as possible. So depending on your style of driving will ultimately depend on how much MPG you get in my opinion. From what i see in the other fullsize trucks out there, the NBS Chevy is no doubt the best choice if you're looking for good fuel economy. CMOS, I'm sure you'll enjoy the truck, I know I surely love mine!

therewolf

Here's food for thought. My 04 -2500HD-4X4-6.0L-342gears gets 18MPG highway, driven conservatively-8ft long bed with a fiberglass cap-K&N CAI & religious maintenance. With a bedcover,simple mods, and conservative driving,If my hog can do 18MPG, your 5.3 should do at least 20 if you play your cards right.

ukrkoz

i have 2000 5.3 vortec, 4wd, slightly lighter truck as mine is only extended cab. i do solid 17.4 to 18 average and 22 hwy. that's in seattle area, hills all over on daily commute.
humane driving style, HALO Brisk spark plugs, K&N air filter( i found from real life CAIs reduce mpg), synthetics all through. twice a year Seafoam through tankful.

Chevyguru

I know a guy that has an 07 crew cab 2wd with the flex fuel and LTZ pkg I think it has 3:42 gears. and He gets wicked milage sometimes just over 600 Miles to one tank. I have an 07 crew cab Z71 4x4 with 3:73 gearsI just puta throttle body spacer on it and I get 17 MPG combinedcity/hwy

Chevyguru

I tried running with the cruise on in my 07 nbs crew cab 4x4 and I find I do slightly better without it as I can coast or peddle it and therefore keep it in 4cyl mode longer.

ukrbyk

i do firmly believe that one can run better mpg with foot than with cruise. cruises are dumm.

as of guy getting 600 miles on his truck - well, there might be 2 reasons for it. 1. he has that bigger tank and runs it dry. then he gets nothing but average mpg; 2. yeah, i can also get 30mpg on my truck. if i forget to reset it to zero after refuel.

anyways, not the reason for my post.i just could not hold myself from posting this:
http://seattlepi.nwsource.com/local/..._needle20.html

sorry for the tease.

IAfarmer

I find driving at 58 mph on cruise yields 20 mpg easily. I've done it twice in the past month on E10. Drive slow and coast a lot, but don't annoy other drivers.

rruelas

I dont know about the 07-08 silverados, but on my 07 tahoe with the 5.3 with AFM, I can get it to stay in V4 mode more often by setting the cruise and manually turn off the a/c compressor by pressing the A/C button and leaving the windows up. I get the cabin really cold, then leave the Recirclation button on when I turn the A/C compressor off. It usually stays cool for a few minutes, but I normally only do this when driving at night or early morning. If you can take it, in the early morning, if you just use the vent and leave the a/c compressor off, you can get better mileage too. Also, if you want a little bit of an edge when passing or taking off at a red light, itseemsto giveyouback a little horsepower. Just my two cents

Ertsride1

I have a 2002 Z71 Ext Cab 4x45.3L with 85K. I have added a Dynomax Muffler, a S&B replacement air filter, andstockeverything else. I did a complete tune up when I purchased it about 7K miles ago and I noticed an average of 1 MPG gain. Right now I avg 14.8 to 15.8 MPG highway and in town.

bubba33

I have a 08 5.3 AFM extcab 4x4 3.73 18in tires. It got 16 on the hwy last week and avg 15. I have used E85 twice and it avg 12.5. It has 2500 miles on it I hope it gets better later on. My 03 cummins got 21 on the hwy and avg 18 and it was a 7500 lb truck.