Decrease in gas mileage/ Hallpech stinger?
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Burning Brakes
Joined: Oct 2004
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From: Whitestone New York
Decrease in gas mileage/ Hallpech stinger?
Installed hallpech stinger intake yesterday, noticed my average gas milage went down... i KNOW COMPUTER WILL RECALIBRATE AFTER ABOUT 50 MILES SO THEY SAY.. Some say i will get better gas mileage with increase airr flow.... what you think..??
Melting Slicks
Joined: May 2003
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From: Massapequa Park, NY [This is Not an EXIT]
After one Day your average went down? I think you should give it more time.
Also don't forget you get worse mileage with the winter gas.
I didnt notice any change in mileage after the Stinger install, but definately noticed a change after the winter gas additives.
Also don't forget you get worse mileage with the winter gas.
I didnt notice any change in mileage after the Stinger install, but definately noticed a change after the winter gas additives.
Team Owner
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St. Jude Donor '05-'06-'07-'10
There is an idle relearn procedure that you can try to "hurry-up" the computer. I know with my Blackwing my mileage is great. I would suspect you will see it even out with a little time. What sort of difference are you seeing? Anyway, Here is a procedure that was posted on the forum some time ago:
Paul
Paul
The car will re-learn simply by driving it between 50-100 miles. Or, the actual way to do it more quickly, is the following procedure:
1) Insert key into ignition and turn to the “ON” position, but, DO NOT START THE ENGINE.
2) Open the engine compartment fuse box cover and remove the two 10 amp fuses from position numbers 16 & 23.
a) According to the manual there are two fuse boxes. Use the engine compartment fuse block for this procedure not the instrument panel fuse block.
b) Engine Compartment Fuse Block (correct one): 16 is Powertrain Control Module A and 23 is Powertrain Control Module B.
c) Instrument panel fuse block (wrong one): 16 is Air Bag, 22 is Body Control Module-Ignition and 23 is Body Control Module-Ignition 2.
NOTE: Your DIC will now display “check” messages for ABS, etc… Do not worry as this is normal.
3) Turn the ignition key to the “OFF” position.
4) Return to the engine compartment fuse box and re-insert both 10 amp fuses for positions 16 & 23.
5a) Idle relearn for an M6:
1) Start the engine and allow the coolant temp to reach a minimum of 176 degrees F. Allow the engine to run at this minimum temperature for at least 5 minutes.
2) After the 176 degree, 5 minute minimum run, shut down the engine for a minimum of 30 seconds.
3) Restart the engine and check for DIC error codes (there should be none).
5b) Idle relearn for an A4: (different)
1) Start the engine and allow the coolant temp to reach a minimum of 176 degrees F. Allow the engine to run at this minimum temperature for at least 5 minutes.
2) Allow the car to idle in DRIVE, with air ON and then OFF, for 5 minutes each, and then in NEUTRAL, with air ON and then OFF, for 5 minutes each.
3) Turn the car off for at least 30 seconds.
4) Restart the engine and check for DIC error codes (there should be none).
6) Drive car for a minimum of 30 miles at varying rpm settings and speeds. PCM will now re-learn and adjust for the new air flow and temperature at the intake.
a) If error codes persist, repeat steps 1-7. Make sure fuses are properly inserted before repeating steps.
b) Do not deviate from the sequence outlined above. If you do, restart the sequence from scratch.
c) Steps 1-4 are also necessary if you ever disconnect your battery or lose power for any reason.
1) Insert key into ignition and turn to the “ON” position, but, DO NOT START THE ENGINE.
2) Open the engine compartment fuse box cover and remove the two 10 amp fuses from position numbers 16 & 23.
a) According to the manual there are two fuse boxes. Use the engine compartment fuse block for this procedure not the instrument panel fuse block.
b) Engine Compartment Fuse Block (correct one): 16 is Powertrain Control Module A and 23 is Powertrain Control Module B.
c) Instrument panel fuse block (wrong one): 16 is Air Bag, 22 is Body Control Module-Ignition and 23 is Body Control Module-Ignition 2.
NOTE: Your DIC will now display “check” messages for ABS, etc… Do not worry as this is normal.
3) Turn the ignition key to the “OFF” position.
4) Return to the engine compartment fuse box and re-insert both 10 amp fuses for positions 16 & 23.
5a) Idle relearn for an M6:
1) Start the engine and allow the coolant temp to reach a minimum of 176 degrees F. Allow the engine to run at this minimum temperature for at least 5 minutes.
2) After the 176 degree, 5 minute minimum run, shut down the engine for a minimum of 30 seconds.
3) Restart the engine and check for DIC error codes (there should be none).
5b) Idle relearn for an A4: (different)
1) Start the engine and allow the coolant temp to reach a minimum of 176 degrees F. Allow the engine to run at this minimum temperature for at least 5 minutes.
2) Allow the car to idle in DRIVE, with air ON and then OFF, for 5 minutes each, and then in NEUTRAL, with air ON and then OFF, for 5 minutes each.
3) Turn the car off for at least 30 seconds.
4) Restart the engine and check for DIC error codes (there should be none).
6) Drive car for a minimum of 30 miles at varying rpm settings and speeds. PCM will now re-learn and adjust for the new air flow and temperature at the intake.
a) If error codes persist, repeat steps 1-7. Make sure fuses are properly inserted before repeating steps.
b) Do not deviate from the sequence outlined above. If you do, restart the sequence from scratch.
c) Steps 1-4 are also necessary if you ever disconnect your battery or lose power for any reason.
Racer
Joined: Jul 2004
Posts: 412
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From: Newport AR
Assuming the computer keeps the air/fuel ratio consistent before and after the change, mileage must decrease. More air requires more gasoline for the same rpm. You produce more power and better acceleration, but not more speed. The only way to increase air and gas flow and keep previous mileage is to change the rear end so that you get more speed per rpm. The only possible exception I can think of is when you run WFO in final gear all of the time, yet your engine will not pull to the rev limiter in final gear, and the extra air flow and gas flow increases your power, allows you to generate move revs and increases top end speed. Where's Keith Cameron when you need him?
Le Mans Master
Joined: Sep 2004
Posts: 5,707
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From: Los Angeles
Originally Posted by GMDGary
Assuming the computer keeps the air/fuel ratio consistent before and after the change, mileage must decrease. More air requires more gasoline for the same rpm. You produce more power and better acceleration, but not more speed. The only way to increase air and gas flow and keep previous mileage is to change the rear end so that you get more speed per rpm. The only possible exception I can think of is when you run WFO in final gear all of the time, yet your engine will not pull to the rev limiter in final gear, and the extra air flow and gas flow increases your power, allows you to generate move revs and increases top end speed. Where's Keith Cameron when you need him?
Safety Car
Joined: Apr 2004
Posts: 3,737
Likes: 10
From: Austin, Texas
Originally Posted by zinbaad
Installed hallpech stinger intake yesterday, noticed my average gas milage went down... i KNOW COMPUTER WILL RECALIBRATE AFTER ABOUT 50 MILES SO THEY SAY.. Some say i will get better gas mileage with increase airr flow.... what you think..??
My mileage went way down because with the improved throttle response and SOTP feel, my right foot got considerably heavier
Seriously, I've had my Blackwing in for about 7K miles now, and my gas mileage hasn't changed at all. When it's all said and done (PCM relearn), you won't see much of a difference.
Team Owner
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St. Jude Donor '05-'06-'07-'10
Originally Posted by GMDGary
Assuming the computer keeps the air/fuel ratio consistent before and after the change, mileage must decrease. More air requires more gasoline for the same rpm. You produce more power and better acceleration, but not more speed. The only way to increase air and gas flow and keep previous mileage is to change the rear end so that you get more speed per rpm. The only possible exception I can think of is when you run WFO in final gear all of the time, yet your engine will not pull to the rev limiter in final gear, and the extra air flow and gas flow increases your power, allows you to generate move revs and increases top end speed. Where's Keith Cameron when you need him?
All of this really needs to be backed up with a free flowing exhaust system as well to vent the exhaust gas post combustion. If you don't the engine needs to work a little harder pushing against the higher restriction during the exhaust stroke. (whew, I need a nap.)
Paul
Melting Slicks
Joined: Aug 2002
Posts: 3,164
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From: Lutz FL
Originally Posted by talon90
I don't entirely agree with you Gary. First the computer does not keep the ratio consistent. The actual air-fuel ratio required by the engine varies depending on engine coolant temperature and load. Thus, the air-fuel ratio is altered according to the running condition to satisfy the engine's requirements for complete combustion. Second, the addition of an aftermarket intake isn't only about more air, it's about a more efficient supply of air than with the generally more restrictive OEM intake. It's all about getting the right volume of air to the cylinder at the point of combustion for the intake stroke. A well designed air intake may provide cooler air than stock as well but the result is a more efficient supply of air, with less restriction such that the computer can adjust for optimal combustion and in theory may infact use less gas as a result.
All of this really needs to be backed up with a free flowing exhaust system as well to vent the exhaust gas post combustion. If you don't the engine needs to work a little harder pushing against the higher restriction during the exhaust stroke. (whew, I need a nap.)
Paul
All of this really needs to be backed up with a free flowing exhaust system as well to vent the exhaust gas post combustion. If you don't the engine needs to work a little harder pushing against the higher restriction during the exhaust stroke. (whew, I need a nap.)
Paul
Exactly what he said!
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Safety Car
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From: Taildragers rule! USA1
Chevrolet has already spent millions figuring this out. If all it took was a different air intake to increase gas mileage they would have had it on in a flash. GM is intensely interested in gas mileage.
ANY aftermarket mod is going to decrease your gas mileage. ANY mod (except the skip shift eliminator) will decrease drivability.
All you have to do is cruise this forum for a while. The vast majority of modders whine and complain how their car won't drive anymore, or becomes a road grader after lowering. And that is why all the modded cars lose value, both monetarily and functionally.
ANY aftermarket mod is going to decrease your gas mileage. ANY mod (except the skip shift eliminator) will decrease drivability.
All you have to do is cruise this forum for a while. The vast majority of modders whine and complain how their car won't drive anymore, or becomes a road grader after lowering. And that is why all the modded cars lose value, both monetarily and functionally.
Le Mans Master
Joined: Sep 2004
Posts: 5,707
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From: Los Angeles
Originally Posted by ztheusa
Chevrolet has already spent millions figuring this out. If all it took was a different air intake to increase gas mileage they would have had it on in a flash. GM is intensely interested in gas mileage.
ANY aftermarket mod is going to decrease your gas mileage. ANY mod (except the skip shift eliminator) will decrease drivability.
All you have to do is cruise this forum for a while. The vast majority of modders whine and complain how their car won't drive anymore, or becomes a road grader after lowering. And that is why all the modded cars lose value, both monetarily and functionally.
ANY aftermarket mod is going to decrease your gas mileage. ANY mod (except the skip shift eliminator) will decrease drivability.
All you have to do is cruise this forum for a while. The vast majority of modders whine and complain how their car won't drive anymore, or becomes a road grader after lowering. And that is why all the modded cars lose value, both monetarily and functionally.
Team Owner
Joined: Jul 2004
Posts: 24,652
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From: NJ
St. Jude Donor '05-'08
It is more about money then about gas mileage (though I think gas mileage is something because of the gas guzzler tax).
I read yesterday that AMERICAN AIRLINES saved $40,000 in 1987 by eliminating one olive from each salad served in first class (http://www.airlinequality.com/main/facts.htm).
Think how much GM is saving by not using better exhaust, rotors, CL, etc, etc, etc - it must be in the millions.....
I read yesterday that AMERICAN AIRLINES saved $40,000 in 1987 by eliminating one olive from each salad served in first class (http://www.airlinequality.com/main/facts.htm).
Think how much GM is saving by not using better exhaust, rotors, CL, etc, etc, etc - it must be in the millions.....
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When I installed my Blackwing, I didn't notice any change in gas mileage. Still got excellent MPG. Give it some time and see how it does.
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From: Anthony TX
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St. Jude Donor '08
I have an 02 ZO6 and was getting 28-30 MPG on the highway at 65-70 cruise on a stock engine and stock tune. I installed Stainlessworks headers, Random Cats, 3' exhaust and mufflers with a K&N filter in the stock air box and now I get 23-24 MPG under the same conditions!!!
I have put 1000 miles in the car since the MOD and can rule out that theory! The engine runs very strong without any problems.
The tune cant be that far off? Or can it????? Do you guys think a tune can bring the milage up? I did gain LOTS of HP and TQ according to the SOTP Meter! and my right foot doesnt have much to do with the decrease. I have tried to be nice and see if that made a difference! IT DIDNT! 
Please let me know what you think!
Thanks
Bill C
I have put 1000 miles in the car since the MOD and can rule out that theory! The engine runs very strong without any problems.
The tune cant be that far off? Or can it????? Do you guys think a tune can bring the milage up? I did gain LOTS of HP and TQ according to the SOTP Meter!
and my right foot doesnt have much to do with the decrease. I have tried to be nice and see if that made a difference! IT DIDNT! Please let me know what you think!
Thanks
Bill C
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From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
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St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
I have a Blackwing and mileage is the same.
Might I suggest.. um.. leaden foot?
Might I suggest.. um.. leaden foot?
Le Mans Master
Joined: Sep 2004
Posts: 5,707
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From: Los Angeles
Originally Posted by Bill Curlee
I have an 02 ZO6 and was getting 28-30 MPG on the highway at 65-70 cruise on a stock engine and stock tune. I installed Stainlessworks headers, Random Cats, 3' exhaust and mufflers with a K&N filter in the stock air box and now I get 23-24 MPG under the same conditions!!!
I have put 1000 miles in the car since the MOD and can rule out that theory! The engine runs very strong without any problems.
The tune cant be that far off? Or can it????? Do you guys think a tune can bring the milage up? I did gain LOTS of HP and TQ according to the SOTP Meter! and my right foot doesnt have much to do with the decrease. I have tried to be nice and see if that made a difference! IT DIDNT!
Please let me know what you think!
Thanks
Bill C
I have put 1000 miles in the car since the MOD and can rule out that theory! The engine runs very strong without any problems.
The tune cant be that far off? Or can it????? Do you guys think a tune can bring the milage up? I did gain LOTS of HP and TQ according to the SOTP Meter!
and my right foot doesnt have much to do with the decrease. I have tried to be nice and see if that made a difference! IT DIDNT! Please let me know what you think!
Thanks
Bill C
) Who knows, you may be missing out on a lot more hp increase with a tune? Having said all that there are some cases where changing the breathing can make it better but sacrifice efficiency at lower rpm. It's possible that the breathing at 1500rpm is all screwed up now but very good above 3k. Sounds like your mods are quite extensive for high rpm use. In other words, under equal acceleration rates the mods will allow the engine to perform with less fuel but while maintaining 1500rpm at highway speeds it may require more.
Burning Brakes
Joined: Jan 2003
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From: New Smyrna Beach Fl
Originally Posted by GMDGary
Assuming the computer keeps the air/fuel ratio consistent before and after the change, mileage must decrease. More air requires more gasoline for the same rpm. You produce more power and better acceleration, but not more speed. The only way to increase air and gas flow and keep previous mileage is to change the rear end so that you get more speed per rpm. The only possible exception I can think of is when you run WFO in final gear all of the time, yet your engine will not pull to the rev limiter in final gear, and the extra air flow and gas flow increases your power, allows you to generate move revs and increases top end speed. Where's Keith Cameron when you need him?
I disagree.... A vehicle with a given weight/drag coefficient/rolling resistance requires "X" hp to move at a given speed. Let's say 60 mph for the sake of discussion. Let's assume that it takes 25% throttle plate opening to achieve that "X" hp. This allows the correct volumn of fuel/air into the cylinders to produce the desired result. (enough hp to go 60 mph) without doing any internal mods (heads/ cam etc) a more efficient intake system will allow the correct amount of fuel/air at a lesser % of throttle plate opening. A normally aspirated engine has a vaccuum in the intake. The vac. is greater after the throttle plate. The engine sucks air into the cylinders. The more efficient intake allows more air in front of the throttle plate, the engine works less to get the correct air/fuel volumn to the cylinders. Thus, the throttle plate does not need to open as far to achieve the same hp. The difference may be very insignificant, and no change in mileage may be noticed, However, if the intake is an extremely efficient one, once the computer setles down, milage should increase slightly. Unless the "lead foot" mod has also been added.
remember.... yes, more air does require more fuel for a proper mixture. But you still need the same total volumn to produce the same hp. A more effecient system requires less throttle opening. Also...as I said above, without internal mods (increased compression ratio) you still need the same volumn of air/fuel at the correct ratio to get achieve the desired hp. The mileage really shouldn't change, all else being consistant with the car b4 the intake mods.
Last edited by SilverBullit02; Nov 11, 2004 at 09:03 AM.
