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Yes, I did search and read several posts, but I need to throw this out there. I have a 2005 E46, Auto(I know, I know), 32,xxx miles. Car is driven local, rarely on the highway. Oil changed religously. Air filter is clean. Premium gas only. MPG now is 16.6 mpg and it seems to be getting worse. Any advice? THANKS!
 

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16.6 local only is pretty good for NYC driving.
 

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what did you get before?
spark plugs? Check them. IF fouled, they will have a negative impact on gas mileage
Tire pressure?
Tranny and diff fluids. Car may or may not benefit from fresh fluids.
 

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I get around 19-21 in city (35mph speed limit kills me).

Change your fuel filter...or at least run some octane booster/fuel injector treatment.
 

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or at least run some octane booster/fuel injector treatment.[/QUOTE]

I dont believe these work..well not the octane booster. I think there is a post about this around here somewhere :hmm:
 

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That sounds about right for an auto in NYC. There isn't really anything you can do to get better MPG in NYC short of getting a Prius.
 

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Yes, I did search and read several posts, but I need to throw this out there. I have a 2005 E46, Auto(I know, I know), 32,xxx miles. Car is driven local, rarely on the highway. Oil changed religously. Air filter is clean. Premium gas only. MPG now is 16.6 mpg and it seems to be getting worse. Any advice? THANKS!
If in NYC then probably just a tad low. Out of nyc, probably more than a tad low.

My 328 won't see below 22 mpg when my average mph is 25...just for reference.

Biggest mileage theft is the thermostat. Take the car on a highway and see if your temp gauge drops below dead center. It will then rise to normal temp in city driving...that's the sign of a 'stuck open' broken thermostat.

Other ideas will help too, but if you've just noticed a change, bet it's therm.

Of course, mpg will be improved a little by a number of little things, all contributing a bit each. Air filter, fuel filter, plugs, cleaning maf, Techron to clean injectors a few times a year, an intake leak would also cost you mpg...most common is lower intake boot, but at the time that cracks, I suspect other rubber things will be dried out and also contribute a little bit to bad mileage. And any of these things could be an issue and wouldn't throw an cel until they're pretty bad.

Good luck, HTH

If you are in or near the city, and want to get your car scanned with a real scanner to see what's in there stored up, let me know. I'll get you into my buddies shop in Union, NJ, not that you couldn't go on your own, but he'll read codes for free for any fanatic. Autozone will also do this but only gives generic OBDII codes; better than nothing and not a bad idea periodically to see what's been stored as a fault, even if it isn't turning on the CEL.
 
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