Bad gas mileage

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Jan 25, 2008 | 05:12 PM

TCW

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From: Richmond, VA

Bad gas mileage

I just went through my second tank since buying the car and i got 14.9mpg. No mods other than cutout, 124k mis, M6, 1999 Transam. Any ideas? Also I just replaced the clutch so I have been taking it real easy(as well as freshly rebuilt tranny).

Thanks

Also it has skip shift, and I try to keep rpms around 1-1.5 when cruising. No CEL(check engine light) or sel w/e its is called.

Jan 25, 2008 | 05:26 PM

Choppers

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try a tune up and fuel filter also maybe a seafoam

Jan 25, 2008 | 05:51 PM

TCW

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Hmm ill do seafoam but only because I want to smoke up the neighborhood, you only get to do this once with 124k of junk, or twice at 248 if it makes it.

Jan 25, 2008 | 11:27 PM

Formula413

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If it's mostly city miles, that's not really out of line. Are you running premium? And don't overlook simple stuff like tire pressure.

Jan 25, 2008 | 11:37 PM

01riceeater

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correct tire pressure +seafoam+new fuel filter should yield you about 3-4 more mpg in the city.

Jan 25, 2008 | 11:45 PM

stefan256

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get a lighter foot

ive heard alot about the seafoam deal seems to help alot of people so i would try it

Jan 25, 2008 | 11:58 PM

ae13291

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From: san fernando valley, california

new spark plugs and wires!! fuel injector cleaner along with the new fuel filter! i always use lucas injector cleaner

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Jan 26, 2008 | 08:16 AM

TCW

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Well it is 95% city, dont know why I didnt think of that in the first place. But ill do the fuel filter & seafoam(in the sticky you put in fuel as well so that checks off injector cleaner) and see what happens.

Jan 26, 2008 | 08:16 AM

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One Bad Z

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Check one at a time in order.
: Tire pressure (not going cause a HUGE decrease in mpg like you have but its a safety factor & will help tire life)
: Fuel Filter
: Plugs & wires
: 02 Sensors
: New exhaust cats
: New or clean the air filter
: Tune

Jan 26, 2008 | 10:05 AM

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silver30th

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yikes buddy, i can avg. around 18-19 if not into the 20s in town...thats when i baby it

Jan 26, 2008 | 04:38 PM

#12

TCW

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Well did the seafom treatment on the sticky and smoked up a 100ft x 20 ft section of road. Now to change the fuel filter after I run through this tank of gass as well as the oil. Then plugs and call it a day.

Jan 26, 2008 | 05:02 PM

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Formula413

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You could also check your PCV valve, take it out and make sure it rattles. A stuck PCV valve can hurt mileage.

Jan 26, 2008 | 07:45 PM

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wssix99

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I don't think you have anything to worry about. On a stock drivetrain after 60K miles, I was getting 12 mpg on pure city (Chicago) driving and 26 mpg on the highway.

After doing a carbon treatment on engine, I got an additional 3 mpg in both the city and on the highway.