Is 20MPG possible

[Z-56 Hoe]

Yeah don't do the pump. I have to I will burn up a stocker quickly. Under sustained heavy throttle my stuck fuel pump starved my engine. And was a costly lesson to learn. Also I have a really good Tunner and have a full tune and retuned on a Dyno Jet dyno to optimize and tweak everything.

On a side note just doing CAI and cat back Exhaust won't do much at all but full exhaust I.E. Long tube headers (LT's) free flow cats or gutted cats , and performance muffler. And getting a tune for those mods will help a lot IMO.

Also what size tires and wheels are you running? Also what year is your rig? Does it have E-fans? What is your final drive ratio? What size gears do you have?

 

[ezdaar]

Surprised noone has mentioned using one of these yet.
Keep vacuum has high as possible during all driving conditions and watch your mpg go way up.
Vacuum Gauge

 

[dcarver]

Interesting info about the E85 Yates.

Z-56, I have an 03 suburban 2wd with stock tires and 3.73 rear end 4spd

 

[Z-56 Hoe]

Interesting info about the E85 Yates.

Z-56, I have an 03 suburban 2wd with stock tires and 3.73 rear end 4spd

What size tires? What are your driving habits? Do you slow start. From stops and coast?

What are the driving conditions? I.E. Heavy traffic like say Rush hour in a larger city with lots of Stop and go driving? If so that will kill your MPG!


I would sea foam everything , clean the throttle body, make sure tires are properly inflated and balanced, and then I would run some Lucas through her. If you don't already have a CAI get one and do more then a cat back and get a tune either a mail order BLACK BEAR or go to a local Tuner.

Watch your RpM gauge and try and keep the RPMs as low as possible. Use Cruise control when at all possible.

But how long do you see yourself with this Sububran? Will you be able to Recoop the money spent to achieve the better econmy ? I have had my Tahoe since brand new she is now 14 years old. And now she is more of a toy and not so much a Daily driver.

 

[dcarver]

Tires are 245/70/16. I have the torque app pro hooked up so I can view all necessary parameters.
My driving habits are really good. No jack rabbit starts, coast a much as possible, drive slowly on my half freeway/half city driving.
I have noticed that the throttle is way different that what i'm used to. Kinda half to push it semi hard to get it up to speed. It's not that the truck is slow though i mean 0-60 is just under 10 seconds so i don't think thats too bad for such a big vehicle.
I'm a little hesitant to do seafoam because it just had plugs and wires done alhtough I guess I could just clean them after.
I'll probably try some injector cleaner first.

I do plan on keeping the burb for 5 years+. I don't care for the nnbs although I think they are incredible to drive, I just can't look at them and I haven't seen a nnnbs in person to comment on them.
I first plan on doing the swiss cheese mod (once I get a new drill) and spectre intake tube, then I can't decide on just a magnaflow muffler or biting the bullet on some LT headers. Then I'll save up a while for the tune. Will the LT's and intake really screw with my air/fuel ratio so much as to warrant a tune immediately or could I get by for a while while saving up?

 

[Big Buttons]

If you get the LTs and get rid of your cats you will have to get a tune to delete the rear O2's. If you get the LTs and keep your cats you will need high flow cats, and I would still get a tune.

 

[dcarver]

Well I'd probably delete them because I've seen the magnaflow cats run about $200. I know the inspection guys pretty well to get away with it. I think I'll just do those 2 together and call it good. At least until I get the itch again lol

 

[Big Buttons]

LPP has some nice LTs with a ORY for $400 right now. I will be getting them next paycheck.

http://lpparts.com/store/page7.html

 

[dcarver]

Do you have to modify anything to get the LTs to fit?

 

[Big Buttons]

If 2wd usually not. 4wd yes for sure you will have to mess with the Y-pipe.

When you get them use your OEM gaskets. Aftermarket ones suck the D...