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MPG

This is a discussion on MPG within the Firebird / WS6 forums, part of the Vehicle Specific category; Not sure if this is the right forum, but anyways, recently I've been getting 17.5-19 mpg, I've changed my plugs ...

  1. #1
    Member Red99TA's Avatar
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    MPG

    Not sure if this is the right forum, but anyways, recently I've been getting 17.5-19 mpg, I've changed my plugs (AC Delco Iridiums), MSD 8.5mm Superconductor wires were put on when plugs changed, and fuel filter, did all of this about 2k miles ago, as far as mods go, I have an SLP lid and cai with K&N filter and cutout, everything else is stock. I try to shift between 1500-2 rpm, sometimes I get on it (5-6 times a week maybe, I've had the car less than 2 months but it is my daily driver so I try to not beat it up too much). I drive about 25 miles round trip every day, 8 of it city and the rest highway. Any advice will help and its an m6 btw, thanks

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    Member egod's Avatar
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    i am about the same, i think getting on it takes a lot more than you think. Are you using 93 octane, which kind, do you always use the same, how are you calculating it?

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    Veteran Hi-Po's Avatar
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    5-6 times aw week... I do that everytime I drive the TA. Just have to.

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    Member Red99TA's Avatar
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    I do use 93 octane, I take however many miles are on my trip and divide it by however many gallons it took to fill up, it took 14.xxx and I had 250 miles on the trip, I usually use QT but today I filled up at valero

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    cammed & slammed Kaotic_ws6's Avatar
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    Quote Originally Posted by Red99TA View Post
    I do use 93 octane, I take however many miles are on my trip and divide it by however many gallons it took to fill up, it took 14.xxx and I had 250 miles on the trip, I usually use QT but today I filled up at valero
    in the city and highway i average 22 if i drive it decent but if its all highway nothing else i get 28- 30

    i thinks thats decent for 420rwhp
    1999 mbm Z m6/ forged 346, lt's, wires, ls6 intake, sts rear turbo.

    *SOLD*2002 black ws6- <Bolt ons, ls6 heads, mild cam, dyno tune, full susp. and 4.10s> --440rwhp/395rwtq

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    Member egod's Avatar
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    Quote Originally Posted by Red99TA View Post
    I do use 93 octane, I take however many miles are on my trip and divide it by however many gallons it took to fill up, it took 14.xxx and I had 250 miles on the trip, I usually use QT but today I filled up at valero
    If you stay consistent with the mileage and gas station i would go have it dyno'd. Maybe they can find something on the log that might be off and cause the lower mpg. It sounds like you've done all you can with the air and spark, anything else that would cause it would probably throw a code, like an o2 sensor or something.

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    Member Mike's TA's Avatar
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    Make sure you check your tire pressure as well. One of the simplest things that effects gas mileage that gets over looked easily.

    You're not driving around with the cutout open all the time are you?

    Also, do you still have stock exhaust?

  8. #8
    Impounded
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    Clean the maf and change your pcv valve with the new style fixed orifice (luberfiner part 1009 at the otterzone).

    If that doesnt help change your 02 sensors, they get lazy over time.

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    Sarge for AAG Emperor hutch1999's Avatar
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    I bet your getting on it more than you let on, to get better mpg you must first lighten your foot.

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    Member Red99TA's Avatar
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    cut out is open all the time, I don't see how that would cause worse mpg since its right before the muffler, and the exhaust is still completely stock besides the cutout, I had to change my MAF because it was causing the rear O2's to read wrong, the O2 codes are gone (nothing in history, pending or current), and I may look into the PCV change, next time I fill up I might cap off the cutout to see if there is a diff, but like I said I don't see how it would so enlighten me if you will, thanks

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    Member Mike's TA's Avatar
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    Quote Originally Posted by Red99TA View Post
    cut out is open all the time, I don't see how that would cause worse mpg since its right before the muffler, and the exhaust is still completely stock besides the cutout, I had to change my MAF because it was causing the rear O2's to read wrong, the O2 codes are gone (nothing in history, pending or current), and I may look into the PCV change, next time I fill up I might cap off the cutout to see if there is a diff, but like I said I don't see how it would so enlighten me if you will, thanks
    Well, I know that when I drove around for a week without a muffler, I only got around 17-18 mpg when I normally get 22.

    Of course, Like others have been saying about you, I might have gotten into it a lot more than I realized that week because I liked the sound of it.

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    Quote Originally Posted by Red99TA View Post
    cut out is open all the time, I don't see how that would cause worse mpg since its right before the muffler, and the exhaust is still completely stock besides the cutout, I had to change my MAF because it was causing the rear O2's to read wrong, the O2 codes are gone (nothing in history, pending or current), and I may look into the PCV change, next time I fill up I might cap off the cutout to see if there is a diff, but like I said I don't see how it would so enlighten me if you will, thanks
    did you go back with a stock MAF or what did you use?

  13. #13
    Member Red99TA's Avatar
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    the maf is stock

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