In the city, I get about 12, highway 15 driving easy on 93 octane, both with the AC off.
On E85 city driving, it's about 8-9, highway is about 13-14... but it's so much more fun on E85

Before the supercharger, headers and cam, I would get about 14 city and about 18 highway (20 if I could keep it at 63-65 the whole time).

Curious about what other people are getting ON A REGULAR BASIS (not this one time going downhill with the wind behind you). Post up yours and what your current mods are


My current mods (since sigs change over time):
2003 Tahoe Z71 5.3 FlexFuel: Radix MP112 10psi, GT2-3 cam, CTS-V h/e, LPP LT's, KB BAP, 75# inj, Wheatley E85 tune, 40k cooler, servos, HD2 kit, '05 fans, 22" Magnaflow, Hotchkis sways, panhard bar, trailing arms, Edelbrock IAS, 3.73s, hydroboost, '07 brakes

 

I get about 7-8 on the streets and 14.9 on the highway with just cruising and no boost at all... But its about to get worse... Mine is all on 93.

 

You stole my cam. I have just about the same rig with TVS2300. If I baby it, I can get 12 in mixed use. I'm about to swap out the cam to try to get a little better mpg. I drive it about 40K miles per year. I'm hoping power doesn't go down too much with a little less cam. If it does, so be it. Trying to haul *** in a 5K lb truck is a little insane....at best

 

Tank avg is ~15 about half and half highway and city And I do burn outs and wot pulls a few times a week

 

Stock - 4.8 / 4l60E / 3.23 Gear / OEM 20's ~28 inch tire

16 mpg 50/50 city highway ...... 19 mpg interstate

Now - 4.8 / ISKY triple 12 / 4l80E / 4.11 gear / circle D triple disk / meth injection / FIC 74#'rs / 305 35 r24 (30.5" tire)

8 mpg 50/50 city highway ...... 14 mpg interstate

Funny how this started as getting some extra power, while keeping mileage close to the same

 

Haven't went on any trips with the 80e. with the 60e rcsb. turbo. 5.3 3.42s i was averaging 16 and getting 20 on long highway trips.lots of wot pulls on bad days really brought it down lol

 

Mine gets right around 13 all city and 18 highway ac off 15 with it on. It got the same bone stock. I'm making plans on how to improve it. We will see....

 

i get 11 around town and on a recent 200 mile trip i got a solid 14 mpg on the freeway driving 70-80 mph.

 

I just had my TVS 1900 installed on my 4.8 5MT RCSB. I just took my truck down to McKinney from SW MO to have the Maggie and LT's installed. I averaged 20MPG. On my way home I averaged 19.5 and that was with some goofing off. I've eliminated the need to downshift on hills which helps. Ran 91/93 both ways.

Around town I've guzzled about 3/8" of a tank since yesterday. I bet I'm averaging about 9/10 MPG since yesterday's fillup. This thing is a hoot.

 

8.5-9 city and 15 hwy. pump 91 mods in sig