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Old 10-12-2010, 11:14 AM   #1
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What affects your MPG?

Hi,
What is the average MPG are you getting in mixed mode driving.. I read on forums that people get 20-22mpg... I barely get 17mpg (60% back roads, 30% highway) and I don't drive very aggresive. and I have a 2000 base 2.7L manual transmission.

Since it's lower then what I read here.. something must be wrong..
I changed spark plugs/tubes, battery has 1year, MAF is 3yo (it's 125...01 version), new engine oil (syntec 10w40), tires are aligned/balanced with 70% thread remaining.
Engine is smooth as silk.. and I usually try to keep above 2500RPM but rarely go over 4-4500 RPM

So what else could affect my mpg?

Thanks
Sasha
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Old 10-12-2010, 11:32 AM   #2
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I drive aggressively 40% and 'normally' the other 60%. Mileage is 2/3 highway 1/3 city.

17.4 mpg

Driving style, shifting rpm, tire pressure, weight, etc all play a part.
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Old 10-12-2010, 11:42 AM   #3
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I usually get 16-17 mpg around town. The 22-27 mpg range is when I have it on cruise control on very long trips and the cruise is set to 65.

What affects my MPG? Putting my right foot into it all the time... if I only had more HP I wouldn't do this as often—but my MPG would probably be a lot lower then.
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Old 10-12-2010, 12:01 PM   #4
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Quote:
Originally Posted by sasha055
Hi,
What is the average MPG are you getting in mixed mode driving.. I read on forums that people get 20-22mpg... I barely get 17mpg (60% back roads, 30% highway) and I don't drive very aggresive. and I have a 2000 base 2.7L manual transmission.

Since it's lower then what I read here.. something must be wrong..
I changed spark plugs/tubes, battery has 1year, MAF is 3yo (it's 125...01 version), new engine oil (syntec 10w40), tires are aligned/balanced with 70% thread remaining.
Engine is smooth as silk.. and I usually try to keep above 2500RPM but rarely go over 4-4500 RPM

So what else could affect my mpg?

Thanks
Sasha
i see what your problem is,you rarely go over 4-4500 rpm...your car is dying of boredom
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Old 10-12-2010, 12:07 PM   #5
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My car is 2.7 which is smaller engine.. and 16-17mpg is mixed driving.. city only it drops to 14-15mpg..

I'm just worried something is wrong and I should fix it..
I think for now I'll just bring it more often to redline.. and stop looking at stupid mpg

Thanks
Sasha
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Old 10-12-2010, 12:32 PM   #6
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I get about 22mpg in mixed driving and up to 30mpg on the highway. Maybe your OBC is wrong. Try measuring the old fashioned way. Fill the tank, log the mileage, drive the car. On next fill up note the gallons added and just divide miles driven by gallons used.
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Old 10-12-2010, 01:10 PM   #7
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Thanks Tpless, that's exactly how I measure it.. I didn't do OBC hack yet.

Thanks
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Old 10-12-2010, 01:17 PM   #8
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Short trips with long warm-up times could make your numbers go down?
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Old 10-12-2010, 01:21 PM   #9
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My right foot.
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Old 10-12-2010, 01:25 PM   #10
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That is low. I can easily average 20MPG in mixed driving, and I'm not driving like grandma either.
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Old 10-12-2010, 01:34 PM   #11
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Find gas stations that sell 93 octane Pure Gas (no ethanol). My gas mileage improves at least 10%. Even 91 octane Pure Gas yields better results.

http://pure-gas.org/index.jsp?stateprov=IL
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Old 10-12-2010, 02:03 PM   #12
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I've also found non-ethanol blended gas can improve performance, but certainly not 10% in MPG. I've seen a couple HP and maybe a fraction of one MPG difference. I've also measured small timing differences.
disclaimer: this was all on my 1999.5 A4 turbo.
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Old 10-12-2010, 02:27 PM   #13
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I get around 16-17mpg, mostly city driving with a very heavy foot. I also have 18x10.5 wheels with 275 rubber, that doesn't help either
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Old 10-12-2010, 02:27 PM   #14
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I'm not lookiing to increase hp/mpg via better fuel or other means (well maybe in future) right now I'm concerned that I'm overlooking something that is not right and I want to get to the root cause

Thanks
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Old 10-12-2010, 02:38 PM   #15
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Are you running 18 or 19 inch wheels? This can sometimes throw off the mpg.

What exactly do you mean by backroad driving? Lots of turns and hills can also lower mpg very quickly.

If your engine is running smoothly and if your local mechanic/dealer says that everything checks out, then I wouldn't sweat. As I mentioned before my City/Hwy ratio is the same as yours and my mpg is also very similar
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Old 10-12-2010, 02:59 PM   #16
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I've noticed that whenever I take some of my girlfriends for a ride, I experience a sharp decline in MPG.
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Old 10-13-2010, 12:56 PM   #17
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Quote:
Originally Posted by Pat
I've also found non-ethanol blended gas can improve performance, but certainly not 10% in MPG. I've seen a couple HP and maybe a fraction of one MPG difference. I've also measured small timing differences.
disclaimer: this was all on my 1999.5 A4 turbo.

In my 2006 Boxster S I easily go from 22-24 MGP to over 26 MPG.

In my 1997 911 (993) Turbo I easily go from 14-16 MPG to over 18 MPG.
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Old 10-14-2010, 06:05 AM   #18
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Other things that effect mileage...

Quote:
Originally Posted by sasha055
Hi,

I changed spark plugs/tubes, battery has 1year, MAF is 3yo (it's 125...01 version), new engine oil (syntec 10w40), tires are aligned/balanced with 70% thread remaining.
So what else could affect my mpg?

Thanks
Sasha
Hi Sasha

You forgot to mention tyre pressures, tyre widths, and having a clean air filter would change things too. Not to mention a lot of cold starts with no warm up, stop and start driving etc.

My 2011 987 has an upshift indicator to increase mileage by telling you when to use a higher gear, in case you can't figure it out for yourself! LOL
BTW I am getting 23-24mpg right now and the car has under 500 miles on it fwiw.

Just drive it and enjoy it! It will never be a Prius.. thank God!

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Old 10-14-2010, 06:32 AM   #19
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The biggest consumption factor for me is leaving the car in fourth at highway speed, sure it would achieve better mpg in fifth but the power on tap and ability to corner and truly enjoy the car are enhanced in when driving it in the powerband.
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Old 10-14-2010, 08:33 AM   #20
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Thanks everyone.. I'll stop worrying about mpg and drive it more aggressively.. gas prices are overrated anyway

Thanks
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