So very soon here I'll be doing my plenum and replacing a bad pre-cat o2 sensor. I'm currently getting 8-9mpg. Hoping to get at least up to 12mpg area once it's finished.

Sound plausible? Might just do a whole tune-up while I'm at it.

 

Do at least the cap and rotor while you have the manifold off. It just doesn't get any easier than that.

As for gas mileage.... I can give ya a definite maybe.

 

Lol, I figured it shouldn't be too hard for a 318, but time will tell.

 

Very plausable.

 

 

The only way I can get my (5.9l 4WD, sporting 265/75 all-terrain tires) truck down to 9MPG is to get all kinds of stupid in city driving. My usual level of stupid, when I go there, will get me down into the mid-10's. Without going stupid, I get 12-13 city. I could probably gain 1MPG just by emptying my toolbox but that's something I'll never do. On the highway running 75MPH or better I get 15+ depending upon how much headwind I encounter.

So, yeah, it's realistic with a good tune-up but those taller tires of yours might get in the way if you're spinning 3.55:1 gears.

 

^ im basically the same as you...


and yes you can boost those mpgs right up doing that....and if you have the deathflash, you need to eliminate that with a tuner.

 

I'd love to get an SCT from Hemifever... doubt the wife will go for it tho.

 

Its eaiser to ask for forgiveness than permission.

 

On the Cap/Rotor, any brand in particular to look for or will ACDelco work?