Any secrets for a bumping MPG on 1998 305?

[GoToGuy]

Worked on and calibrated Aircraft weigh scales, for DND Canada. Each one could take a lot of LBs, KGs. One per wheel, too get a take off weight for a loaded C130.

Yeah, to get a new or corrected Zero Fuel Weight. At the C5 Galaxy Iso Docks had scales built into floor, wt check part of cycle.

 

[cubandeathgrip]

Wow, Great response.
Thanks for all the feedback, you guys are great.
The changes I like to make, after reading all the responses.

1: do a Highway lean.
How to make this mod? this mod interest me the most, sounds like a fuel flow mod.
I have the stock fuel injection for this year truck, like to research more on the fuel injection system.

2: replace stock air filter with K&N OEM fit/on amazon for 69$

3: EGR delete.
I how do I update ECU as to avoid an engine light?
Is there a instructions on GMT400.com for that?

4: open the exhaust .
Not looking for a loud sound, so maybe a chamber type muffler.
And a cat delete/or high flow. will the cat removed throw an engine light?

5:change rear end lube to synthetic.
BTW, I have a 14 bolt/semi floating axle/from what i can find on the internet about this truck.
305/6 lug/C2500
How do I find out what gearing I have?
I do about 70 mph on the highway, am around 1800 rpm.



thanks

the Grip

 

[Frank Enstein]

Simpsons? Skinner?

???????????????

 

[PlayingWithTBI]

1: do a Highway lean.
How to make this mod? this mod interest me the most, sounds like a fuel flow mod.

3: EGR delete.
I how do I update ECU as to avoid an engine light?

With a 0411 swap and get someone to flash it for you these will be included.

2: replace stock air filter with K&N OEM fit/on amazon for 69$

Don't waste your money, you already have a CAI from GM.

4: open the exhaust .
Not looking for a loud sound, so maybe a chamber type muffler.
And a cat delete/or high flow. will the cat removed throw an engine light?

A straight through muffler will give you better performance and economy. The flash tune will delete the downstream O2 sensors. If you remove the cats, it'll be quite a bit louder too.

Here's the results of an Engine Masters episode where they compared mufflers and 2-1/2" true duals against 3" Y single. Keep in mind duals with an H or X pipe will perform better. Bur, look at the difference in "Turbo" compared to "Straight Through" mufflers.

You must be registered for see images attach

 

[b454rat]

I put a 3" single flow thru muffler on my Tahoe. Borla XR1 muffler. I lost power and torque. I had headers, no cats, mandrel bent pipes, 2.25" to 3" Y-pipe, Borla, single 3" mandrel tail pipe stock location. When I put the cat back on is when i lost power. Dunno how, the stock was small from a patch, dunno how it would even rev. Sounded good tho....Oh and a tune for all that, along with no EGR or down stream O2s. Didn't notice a difference.

 

[df2x4]

2: replace stock air filter with K&N OEM fit/on amazon for 69$

Like PlayingWithTBI said, don't waste your money. I can tell you first hand that running oiled gauze filters in these trucks is a bad idea. You won't gain anything, and you'll introduce the possibility of a fouled MAF sensor due to oil and dirt buildup in the intake tubes. I have a drop-in K&N filter sitting on a shelf in the garage that I removed from my red truck years ago (along with a full K&N FIPK intake kit, also garbage) for these exact reasons. IMO the best filter to run in the '96+ factory intake is the ACDelco high capacity (K47) OEM paper filter. Part number A1301C.

www.amazon.com/gp/product/B000A6X56U

FYI, the only company who makes aftermarket intakes for these trucks which are an actual improvement over the stock setup is Volant. All the others (Like K&N) are an open box design that draws hot air from the engine compartment, Volant maintains a sealed box that draws cool air from the factory fender hole.

 

[cubandeathgrip]

Highway Lean Cruise​

How do I do it, what is needed?
I was a field tech by trade, fixing all types of computer hardware and reprogramming the new hardware.

I like geeky things, where can I find this info to tweak my truck?

 

[cubandeathgrip]

So what's the down side? It being disabled make no sense to me in a day and age with CAFE, unless maybe more emissions... maybe NOx?

How can I check to see if this is enable? I can this mod be done if needed?

 

[PlayingWithTBI]

I like geeky things, where can I find this info to tweak my truck?

Here's a forum pretty much dedicated to tuning. 1st you wanna decided if you should do the 0411 (and WBO2) swap or stick with your black box.

www.gearhead-efi.com/Fuel-Injection/forum.php

 

[honkon]

sell it and buy a corolla for daily
I dunno anything about this "highway lean" mod but the name alone sounds like a recipe for engine detonation, also makes me think of the problematic chrysler "lean burn" strategy from the 70s.