ive got a 5.3 and 4l60e in my 87 silverado s/b. 3.08 gears and im getting what i feel is shoty gas mileage. im pulling a mear 16.11 mpg freeway. im cruising at 60-80 (80 @ 2000 RPM) with the crappy 3.08's i should be getting better no?
i left a message with nelson performance to see about getting a tune, so i will have to wait for them to call me.
**if you have some wicked cool setup and get superb MPG, i dont care. your post will only be taking up e-space

basically wanting a stock 5.3 truck with any gear (4.10 and lower, pref. closer to the 3.08 - 3.23's) and what gas mileage you get.
thanks!
clint

 

04 crew cab mods in sig 3.73 29" tire 13.5 city. have not been on highway since cam swap. my father-in-law has a stock 06 crew with 3.23 and he gets about 16 mixed driving. both 2wd

 

05 rcsb with 3.23s only mod is a generic cat back but according to my gauge i get between 17 and 18 in mixed but mostly city driving, highway is around 22.

 

05 CCSB 2wd mods intake,exhaust,w4m tune, stock tires,323s.. at best ive seen 19.8 but im at 19.4 now.. mostly highway. around 65mph

 

I have 2 trucks, a modded 2003 GMC RCSB Z71 and a stock 2005 GMC ECSB Z71.

The "stock" 2005 Z71 has 4:10 gears and if I use my cruise control on the Highway I'm getting right at 19.2 MPG. It dosen't even have a K&N filter....bone stock

My 2003 Z71 however with 3:73's, Eaton LSD, Transgo Shift Kit, Valve Body upgrade, GM CAI, Pacesetter LT's, Nelson Tune and 275/70 R16....is getting 17 MPG on the Highway. Only about 15 in city driving.

 

the first one must have a k&n sticker atleast lol jk

ill tell u what, after i added the catback my mpg went up nicely.. the tune didnt do anything until i took it out to get retuned.. then it dropped from 19.6 to 19.2, i will be puttin the pcm back in and see if it goes up.

 

I get about 20-22 on the highway. It varies with speed.

 

04 CCBB 5.7L Radix 3:73 Stock SS wheels and tires 19-21 MPG on the highway.

 

Thanks for the replies... i guess my haas just needs to be tuned professionally. since my job is 17 miles all freeway i will post up a new MPG after i get a hold of nelson performance.
clint

 

A tune should help alot, but I still think you should be getting better highway mileage. With those 308's you should be getting some killer mileage on the highway, 80 mph at 2 grand!! I hit maybe 70 mph at 2 grand in my 2001 Z71!! It is bone stock ECSB, 5.3, 4L60, 373's, and it gets 19 mpg on the highway crusing at 65-70 mph. It has no tuning, cai, catback, efans, nothing bone stock 5.3.