PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Why Bad Gas Mileage?!

Thread Tools
 
Search this Thread
 
Old May 8, 2009 | 01:35 AM
  #1  
Xtreme57's Avatar
Thread Starter
TECH Regular
iTrader: (6)
 
Joined: Feb 2003
Posts: 434
Likes: 0
From: Nj
Default Why Bad Gas Mileage?!

Hey guys,

Disregard the h/c setup in my sig - i am currently running h/c from an 03 Zo6 along with all the other mods in the sig (LTs, Underdrive, home ported TB, etc). I split a copy of LS1edit with a friend who has an 02 Z28.

Once we put on the Ls6 stuff in my car we used flashed my car with his stock tune and made only VERY minor changes, YET i still seem to get poor mpg (18 avg with a 50/50 city/highway split, and at BEST 220 miles per tank - that is down to the 'check gauges light btw).

I can't figure out why I get the mpg I'm getting - I drive VERY conservatively. No hard throttles, no redlines anymore, low rpm shifts, very grandmother-y quite honestly. So I can only assume it could be the tune.

Any thoughts as to why this is going on?
Reply
Old May 8, 2009 | 09:44 AM
  #2  
Old Geezer's Avatar
TECH Senior Member
iTrader: (3)
 
Joined: Jun 2004
Posts: 5,639
Likes: 71
From: GA, USA
Default

NE data logs??
Reply
Old May 8, 2009 | 12:40 PM
  #3  
Xtreme57's Avatar
Thread Starter
TECH Regular
iTrader: (6)
 
Joined: Feb 2003
Posts: 434
Likes: 0
From: Nj
Default

Originally Posted by Old Geezer
NE data logs??
I'll get them and post asap.
Reply
Old May 8, 2009 | 06:04 PM
  #4  
Pharcyde50's Avatar
11 Second Club
iTrader: (11)
 
Joined: Aug 2005
Posts: 574
Likes: 0
From: St. Petersburg, FL
Default

I raised my cruising timing up some which helped. You can also adjust O2 r/l vs airflow mode to help out some. I lowered my values in airflow modes 6-10 to 350. A log with a wb O2 would be the best though.
Reply




All times are GMT -5. The time now is 09:13 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE