G37 Coupe

Anybody get terrible mpg?

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Old May 18, 2016 | 01:35 PM
  #91  
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Originally Posted by slartibartfast
Best mileage will be obtained at the lowest speed that the transmission will stay in top gear. For me, that's about 48 mph.
Yeah 48 seems right there in the happy spot. Pretty much the least amount of throttle required to maintain the highest MPH in the highest gear is going to be the best for any car. Every transmission will differ but for me in the 5AT, 48 is just about as good as it gets.
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Old May 18, 2016 | 07:03 PM
  #92  
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Originally Posted by Kris9884
Unimaginable huh? The 7 speed would be marginally better, still under 30mpg on the highway, that seems to be the absolute cap on these. Plus, the 5 speed is a proven reliability beast, its not as unbearable as you think .. The more I think about swapping in the 6 speed I have the more I think how much I'll miss the paddle shifters, I love those things for spirited driving days and don't miss the clutch AT ALL in the other 95% of my daily driving days. Hope your plastic CSC doesn't go out on ya dude..
I have jwt clutch with heavy duty slave cylinder. Yeah I've been through 2 slaves and I bought the external slave cylinder kit that broke on me. Yea. Been through it all. I had a stage two kit with a heavy pressure plate that kept breaking the slaves. And didn't realize that. Now I have a oem pressure Plate with heavy duty slave(:
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Old May 19, 2016 | 03:15 PM
  #93  
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Originally Posted by Kris9884
I didn't even get that exact, I just kept track of the miles driven from when the gas nozzle clicked off on the pump to when the dash said I had 25 miles remaining. I could possibly get a little better if it was a more consistent speed limit but from STL to my house it ranges from 55-75 MPH with numerous small towns in between where traffic picks up. I'll have to redo it when I go to Chicago or Dallas this summer. I REALLY want to break into the 30's on the 5AT.. High hopes maybe..
I have a 5at coupe and I have broken 30mpg many times and I am talking about roundtrips, one way is misleading. If I hypermile and stay around 62, I can do 31+ mpg.

If you want to use the cruise control then you should keep around 56mph and unless you have hills etc. you will probably break 30mpg.

5at's problem is when you get closer to 70 mph, the rpms are simply too high to get good mpg at that speed, 7at's tall 6-7 gears help a lot.

Also if you go below 50 the mpg of 5at will be almost the same as the mpg of 7at (around 45mph you will probably approach 35mpg).

Unfortunately we don't really know how much mpg 7at brings since the data is from different roads, different elevations, different fuel grade and these make a huge difference.
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Old May 19, 2016 | 05:15 PM
  #94  
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From: MO
Originally Posted by ThebigJ
I have a 5at coupe and I have broken 30mpg many times and I am talking about roundtrips, one way is misleading. If I hypermile and stay around 62, I can do 31+ mpg.

If you want to use the cruise control then you should keep around 56mph and unless you have hills etc. you will probably break 30mpg.

5at's problem is when you get closer to 70 mph, the rpms are simply too high to get good mpg at that speed, 7at's tall 6-7 gears help a lot.

Also if you go below 50 the mpg of 5at will be almost the same as the mpg of 7at (around 45mph you will probably approach 35mpg).

Unfortunately we don't really know how much mpg 7at brings since the data is from different roads, different elevations, different fuel grade and these make a huge difference.

Good to know. I used cruise control at about 75mph but there are several hills and slowdowns of traffic etc.. I would love to break 30 too.
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Old May 20, 2016 | 11:18 AM
  #95  
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I was tire shopping today and noticed my current tires (G-Force COMP 2) are terribly rated for gas mileage although they are very very highly rated performance tires. I wonder if I got the all seasons or just another brand for better mileage if that would make a noticeable difference? Not sure the loss in performance is worth the small gain in mpg though.
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Old May 20, 2016 | 11:22 AM
  #96  
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A thousand miles on the PSS, I can't say the mileage increased or decreased. Averaged around 24-25 mpg with mostly highway and backroad driving. About the same as I got last fall for the same trip.
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Old May 20, 2016 | 11:30 AM
  #97  
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Interesting chart. Keep in mind how much air resistance (at higher speeds) effects fuel economy.
Attached Thumbnails Anybody get terrible mpg?-capture.jpg  
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Old May 20, 2016 | 12:35 PM
  #98  
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Good find ^^ that adds some insight to it.. Apparently Diesel is where its at.
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Old May 20, 2016 | 02:03 PM
  #99  
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Frictional drag vs aero dragplot
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Missing is engine drag which is proportional to rpm. Thus the desire to drive in the highest gear at the lowest speed.

A Newton is a unit force and is equivalent to the weight of an apple at Earth's surface.
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Old May 20, 2016 | 03:21 PM
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So a Buick Park Avenue's most efficient speed is about 44.7 MPH
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Old May 20, 2016 | 05:02 PM
  #101  
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And that will be close to the same for most cars.
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Old May 21, 2016 | 03:03 AM
  #102  
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I avg about 280 miles on a full tank of gas running 87 octane.
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Old May 21, 2016 | 05:35 AM
  #103  
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180 miles...on a full tank.
just filled up tonight and it stopped at 11 gallons

...what?
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Old May 21, 2016 | 09:41 AM
  #104  
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Originally Posted by ibeg37s
I avg about 280 miles on a full tank of gas running 87 octane.
That's going to be based off of the nav screens averages since thelast reset, if ever. Go reset that in the mileage screen and see where it puts you for your current driving style.


Originally Posted by chinabean
180 miles...on a full tank.
just filled up tonight and it stopped at 11 gallons

...what?

Unless your gas gauge is wrong there's no way lol.. Its a 20 gallon tank so even if you wait for the light to come on there tends to be 2+ gallons remaining. Although even then there may be more, my roommate and I took his sedan to PCB last year and we drove it almost 100 miles after the light came on to the nearest gas station lol
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Old May 21, 2016 | 01:44 PM
  #105  
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I think it's messed up, my range on full tank says 220 but drops to 210 right after I drove out of the gas station and after driving about 14 miles the gauge shows 3/4th tank left..
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