Dont fall into the trap of thinking that plugs, air filters and the like will do anything for your MPG.

A 5.3 will get about 16 city, 20hwy. Thats just how it is. Sorry.This is under the assumption that you dont have 38in tires.Dont spend any more $$ on parts. This is the gas mileage you have to live with.

My truck is an ECSB with the 5.3, 20s, and 3.73s. I get about 16.5 around town, and it will get 22 at 65mph. If I bump it up to 75mph, gas mileage drops to 18mpg.

 

A good tune is about the best thing you can do for mileage. Its the main thing I recommend for mileage; e-fans are another option but I didn't notice any difference when I put mine on.

 

What kind of truck do you have?

 

N/A, bolt-on 5.3L with 4L6xE & 4.10s - 18mpg (hwy) @ 70mph... that's with it mildly tuned (& a rich AFR).

 

Mines got a Stock 4.8 with Corsa Sport...16.5...but i drove the **** out of it everywhere!

Dustin

 

It's a truck with a big V8

 

As for free mods, if it's a 4wd, you can do the poor man's lowering job by getting some shorter U bolts made for the back, removing the lift blocks, and cranking down the torsion bars a bit. In theory, you have less wind resistance and should therefore get better mileage. You probably won't, but it won't be because you're not trying. I know, it sucks dude, but be thankful you live in USA and not Canada where regular gas is currently selling for $4.95 a gallon...

 

mine is about 16mpg in town if i cruise. If im not cruisin which im usually not then its about 12 or 13. and 22 on the hwy. and that was before the volant intake. i havent made any long distance trips with the intake yet to see the difference on the hwy.

 

04 rcsb w/5.3 ....k&n drop in and corsa exhaust

 

05 rcsb 3.73 stock 17's about 16mpg, i would get a tune and get used to it or buy a civic gotta pay to play man!