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Help me improve my mpg

Old 03-17-2008, 08:57 AM
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dudegetalife
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Default Help me improve my mpg

I have a 2004.5 roadster with 58k miles

before i bought it they topped off all the fluids and did an oil change. Tires/ wheels are aftermarket but they are checked once every week/week and a half at discount tire so they always have the correct psi.

I am only getting about 190-200 miles per tank ( i fill up with 13-14 gallons) and the computer tells me i'm getting 16mpg. ( all city trying to keep rpm's under 3k and brake gently)

Any things that i can do to get my mpg up to at least 18 like my previous car a mustang that was a v8??
Old 03-17-2008, 09:36 AM
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kelsey_kaye
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drive on the highway more..... i only get around 17-19ish in the city.
Old 03-17-2008, 09:38 AM
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ZKansasZ
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I have the same problem...and its costly since our car needs 91+ octane...

Anyway, should we need to keep the RPM from 1800-2200 for good mpg?
Old 03-17-2008, 09:42 AM
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cheshirecat79
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City mpg is terrible. Your figures aren't that far off the mark.

I haven't found a way to get 20mpg in the city regardless of driving style and shift points.

Take it on the highway for 10 miles uninterrupted at around 70mph and see what your mpg is. If it isn't over 20 you have an issue.
Old 03-17-2008, 09:56 AM
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dhwang80
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checked your air filter? Mine had a bunch of fall leaves blocking air flow.
Old 03-17-2008, 10:00 AM
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cp2
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Mine was doing the same. about 16 mpg, mixed city and highway and it says I did an average of 21 mph. Last week I took someone else's and advice and tried as much as possible to stay under 3000 rpm and whadya know, I actually went to work and back all week on the same tank when I was used to filling up at least on thursday. I can go up to 80 mph in 6th I believe which is faster than I need to go, but sometimes I'm in a rush. Try it out and get an oil change and air filter change as well. I just did, so maybe my mileage will get even better.
Old 03-17-2008, 10:01 AM
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kham25
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I get 16.3 MPG on my Stock 07 Normal i guess
Old 03-17-2008, 10:04 AM
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dudegetalife
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what is the oil presure needle supposed to be whenever your idleing????

Anyone want to post a howto link on changing/cleaning air filter?
Old 03-17-2008, 10:06 AM
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y_b_lamron
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I didn't believe it until I saw it for myself but my mpg went up a little bit after putting nitrogen in my tires.
Old 03-17-2008, 10:26 AM
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rockinbboy
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Originally Posted by dudegetalife
what is the oil presure needle supposed to be whenever your idleing????

Anyone want to post a howto link on changing/cleaning air filter?
About 15 or 14 psi I think. The stock needle should be about half way though the quarter mark (so an 1/8 of the full gauge)
Old 03-17-2008, 03:05 PM
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dudegetalife
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Originally Posted by rockinbboy
About 15 or 14 psi I think. The stock needle should be about half way though the quarter mark (so an 1/8 of the full gauge)

mines between 0 and a quarter when idle.

Just got a new oil change, anyone know what might be wrong??
Old 03-17-2008, 03:09 PM
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blasian
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Last fill up I had 23MPG with mixed driving. I never had a fillup in the teen MPG range...
Old 03-17-2008, 03:11 PM
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Catchmeifyoucan
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best you can do is to unplug 3 ignition wires. This will increase your mpg from16mpg go 32mpg.
Old 03-17-2008, 04:22 PM
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blaukal
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Originally Posted by Catchmeifyoucan
best you can do is to unplug 3 ignition wires. This will increase your mpg from16mpg go 32mpg.
Old 03-17-2008, 04:30 PM
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LHsilver350z
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also one of your spark plugs could be bad. i had one go bad and i was only getting 14 on highway and was like WTF. replaced them and it was fine. wierd i know
Old 03-17-2008, 04:33 PM
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06g35meister
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try putting in a round or two of techron, that stuff works like a charm, i put in a bottle every 1000 miles, and its GREAT for the fuel system...
Old 03-17-2008, 04:38 PM
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LHsilver350z
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ya forgot to add injector and fuel system cleaner. Im a tech and would try that since its only like 20 bucks
Old 03-17-2008, 05:35 PM
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dudegetalife
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when should you normally replace the spark plugs/wires on a z , on the mustang you replaced them every 70k....
Old 03-17-2008, 05:57 PM
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LHsilver350z
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i would every 60k on a Z. dont worry about the wires themselves. just the plugs
Old 03-18-2008, 02:04 AM
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cp2
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Hey, does all the extra additives REALLY work for fuel preservation and stuff? I never really believed in it.
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