2008 535i 18.3 mpg???
03-26-2010, 06:25 AM
#21
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My Ride: 530i n52
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Sigh. I'll just leave these here for you to review:
BMW e46 style 68 17x7.5 - 21 lbs
BMW e46 style 71 18x8 - 21 lbs
Granted they are not your example 18" and 19" but it should give you the idea that your weight can remain the same even by one inch larger diameter.
Coefficient of friction <- most important. It's the reason all the high MPG cars and bicycles have skinny little tires; cuts down the drag.
Uh, because it's cheap. And in the case of the engine cover it is to reduce noise. Has nothing to do with weight.
BMW e46 style 68 17x7.5 - 21 lbs
BMW e46 style 71 18x8 - 21 lbs
Granted they are not your example 18" and 19" but it should give you the idea that your weight can remain the same even by one inch larger diameter.
Coefficient of friction <- most important. It's the reason all the high MPG cars and bicycles have skinny little tires; cuts down the drag.
Uh, because it's cheap. And in the case of the engine cover it is to reduce noise. Has nothing to do with weight.
03-26-2010, 06:34 AM
#22
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love how this thread turned into a physics discussion 
03-26-2010, 08:47 AM
#23
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My Ride: 545i Sport Package, Black/Grey. Got it July 09.
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maybe your MAF sensor's dirty?
still I'd be pretty happy with 18.3 mpg
I get about 16.5 and I drive highway a lot
and like a grandma (80% of the time)
still I'd be pretty happy with 18.3 mpg
I get about 16.5 and I drive highway a lot
and like a grandma (80% of the time)
03-26-2010, 10:48 AM
#24
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My Ride: BMW E60
Model Year: 2016
One of the forces at play here is called Moment of Inertia. You can have a 17" 22 lbs wheel and a 20" 20 lbs wheel. The 20" wheel requires more power to accelerate due to Moment of Inertia even though it's lighter. Different tires and how wide they are also increases/decreases rolling resistance and Moment of Inertia.
03-28-2010, 10:34 AM
#25
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My Ride: 2008 535xi Monaco blue / beige Dakota leather , sport package , premium package ,cold weather package , nav , iPod connectivity
I get lik 11 12 new York city and I use ds all the time
03-28-2010, 12:45 PM
#26
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My Ride: 2010 535xi
03-28-2010, 01:21 PM
#27
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My Ride: 2008 528i, Space Grey, Nav, PDC, Premium, Sports, Grey Leather, Xenon, Cornering...
That is weird... My car always gives me great mileage per gallon. I get about 800 miles to the fillup. I think that is good.
03-28-2010, 03:39 PM
#28
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The e60 is a heavy car and city driving will yield horrible mpg on average, especially start/stop and rolling into and out of parking lots during lunch rush. There are days I ride a good traffic flow 6 miles to work, tapping pedal like granny and arriving with a short lived grin of 24 mpg reading. By lunch time the same trip reset of 6 miles is now down to 19 mpg after inching in and out of parking lot with the lunch bunch. The very next day taking the same route to work, if traffic flow ain't optimal 5+ red lights, the iDrive gizmo geezer is now sticking it to me with a reading of 18 mpg.
So to combat this owner/operater cost, at least from what I've read about the free flow exhausts which can typically increase on average by 1 - 2 mpg. Engine breathes better, runs cooler, lighter T304 steel blah blah...but enuff to give me a glimpse of hope that if my city average increases from 17 to 18 mpg at current gas price. I can get my return on investment
on the RPi exhaust in about 12 years! So I justify myself with a motivation to go out and blow loadsa money on an exhaust! Now is this logical thinking or am I fooling myself? 
Does anyone agree or disagree that 30+ lbs lighter freer flowing exahaust can help increase average mpg?
So to combat this owner/operater cost, at least from what I've read about the free flow exhausts which can typically increase on average by 1 - 2 mpg. Engine breathes better, runs cooler, lighter T304 steel blah blah...but enuff to give me a glimpse of hope that if my city average increases from 17 to 18 mpg at current gas price. I can get my return on investment
on the RPi exhaust in about 12 years! So I justify myself with a motivation to go out and blow loadsa money on an exhaust! Now is this logical thinking or am I fooling myself? Does anyone agree or disagree that 30+ lbs lighter freer flowing exahaust can help increase average mpg?
03-28-2010, 05:50 PM
#29
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My Ride: 545i Sport Package, Black/Grey. Got it July 09.
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03-28-2010, 06:44 PM
#30
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My Ride: 2010 535xi
Thanks! These sound like wheels I'll never be able to afford, but they look stunning! 
16 lbs!!!
16 lbs!!!