Trip Computer... Mine is Accurate...

Shipkiller · 06-02-2010, 07:23 PM

After three years on the Z4 forums, the reoccurring issue with the trip computer is that it is for the most part, too optimistic.

Mine must be 'broken' because mine seem to be very accurate.

When I bought the car in Feb, it had 4100 miles. Now it has 10.5K.

I always reset the computer and trip odometer every fill up and do the calculation to make sure of the numbers. My trip computer never seems to be more than .5 off of calculated and normally is only .1 - .2 off. While I don't record these numbers, I keep track for early determination of a engine issue that does not throw a CEL light. This helped me determine that my O2 sensors on my Roadster were bad a year or so ago...

I also wonder if they updated the algorithm on the 2008 models.

Any one else have a accurate trip computer?

I know this is a weird post. Just wondering/musing...

inTgr8r · 06-02-2010, 07:27 PM

I haven't checked mine.

Hawkeye · 06-03-2010, 08:48 AM

Mine is very very accurate as well. I track it in comparison to what Fuelly.com tells me for each fill up and it is usually spot on. maybe a few tenths off tops.

That being said I am averaging 27.2 mpg over the last 6 fuel ups! Much better gas mileage than I thought I got in my car.

Shipkiller · 06-03-2010, 11:50 AM

27.2. I am glad I am not the only one.

When I set the cruise at 75, I get 27MPG. I was expecting 22-24MPG.

That being said, when the RPM goes above 3K, the gas gauge starts to move much faster..

inTgr8r · 06-03-2010, 11:54 AM

Quote:

Originally Posted by Shipkiller

27.2. I am glad I am not the only one.

When I set the cruise at 75, I get 27MPG. I was expecting 22-24MPG.

That being said, when the RPM goes above 3K, the gas gauge starts to move much faster..

& so do you

Hoa · 06-03-2010, 12:05 PM

i get the same amount if i do hwy only. if i mix it with 50% hwy and 50% city, i only get 23.7mpg. i do have a heavy foot once in a while

Hawkeye · 06-03-2010, 02:13 PM

I usually travel between 80 and 90mph on the highway and still seem to get the good mileage. I also am usually spirited while driving around town

dekaliber · 06-03-2010, 04:49 PM

By trip computer being off, do you mean whatever algorithm it's using is misreporting estimated range, mpg, average speed, etc.?

I don't have enough data to say for sure on the M, but it hasn't given me a reason to doubt it. I kept a spreadsheet of each fillup and odo reading when I had the 3.0si, and I found it to be pretty accurate.

Sadly, accurate would now mean a whopping 15.8 mpg combined (heavily local) on the M.

Hoa · 06-03-2010, 05:05 PM

Quote:

Originally Posted by Hawkeye

I usually travel between 80 and 90mph on the highway and still seem to get the good mileage. I also am usually spirited while driving around town

i drove a 11 hour trip straight from miami to atlanta going 80-90 as well. the computer shows 24mpg. it was on cruise 95% of the time.

scottyD · 06-03-2010, 05:14 PM

My computer is also very close - within a few tenths of a mile per gallon...

60mph cruise on flat roads (a/c off) gets you around 38 to 40 mpg in the 3.0si. I'm still amazed at the fuel efficiency of these engines.

Hawkeye · 06-04-2010, 10:10 AM

Quote:

Originally Posted by Hoa

i drove a 11 hour trip straight from miami to atlanta going 80-90 as well. the computer shows 24mpg. it was on cruise 95% of the time.

That seems outstanding for an M. You have to remember I am in a 3.0si. Best MPG I got was doing exactly 70 for an entire tank (following someone, it sucked) and I got 33.7 mpg.

06-02-2010, 07:23 PM	#1
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	Trip Computer... Mine is Accurate... After three years on the Z4 forums, the reoccurring issue with the trip computer is that it is for the most part, too optimistic. Mine must be 'broken' because mine seem to be very accurate. When I bought the car in Feb, it had 4100 miles. Now it has 10.5K. I always reset the computer and trip odometer every fill up and do the calculation to make sure of the numbers. My trip computer never seems to be more than .5 off of calculated and normally is only .1 - .2 off. While I don't record these numbers, I keep track for early determination of a engine issue that does not throw a CEL light. This helped me determine that my O2 sensors on my Roadster were bad a year or so ago... I also wonder if they updated the algorithm on the 2008 models. Any one else have a accurate trip computer? I know this is a weird post. Just wondering/musing...
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06-02-2010, 07:27 PM	#2
inTgr8r Lieutenant General 2426 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	I haven't checked mine. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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06-03-2010, 08:48 AM	#3
Hawkeye Brigadier General 2070 Rep 4,365 Posts Drives: '07 Z4 Coupe, '21 X3, '16 GMC Join Date: Aug 2007 Location: Iowa iTrader: (0) Garage List 2016 GMC Sierra SLT [10.00] 2008 Yamaha R6 [9.00]	Mine is very very accurate as well. I track it in comparison to what Fuelly.com tells me for each fill up and it is usually spot on. maybe a few tenths off tops. That being said I am averaging 27.2 mpg over the last 6 fuel ups! Much better gas mileage than I thought I got in my car. __________________ 2007 Z4 3.0si Coupe • 6 MT • Black Saphire Metallic • PP • SP 2016 GMC Sierra SLT Z71 Premium Plus 4x4 2017 Harley StreetGlide • Denim Black • V&H Tune 2021 BMW x30i • Phytonic Blue Metallic • Fully loaded
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06-03-2010, 11:50 AM	#4
Shipkiller Colonel 187 Rep 2,138 Posts Drives: Me Join Date: Oct 2007 Location: Virginia Beach iTrader: (3) Garage List 2008 BMW Z4M Coupe [8.50] 2003 BMW Z4 Roadster [8.33]	27.2. I am glad I am not the only one. When I set the cruise at 75, I get 27MPG. I was expecting 22-24MPG. That being said, when the RPM goes above 3K, the gas gauge starts to move much faster..
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06-03-2010, 12:05 PM	#6
Hoa Major 513 Rep 1,356 Posts Drives: BMW Join Date: May 2010 Location: GA iTrader: (9)	i get the same amount if i do hwy only. if i mix it with 50% hwy and 50% city, i only get 23.7mpg. i do have a heavy foot once in a while
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06-03-2010, 02:13 PM	#7
Hawkeye Brigadier General 2070 Rep 4,365 Posts Drives: '07 Z4 Coupe, '21 X3, '16 GMC Join Date: Aug 2007 Location: Iowa iTrader: (0) Garage List 2016 GMC Sierra SLT [10.00] 2008 Yamaha R6 [9.00]	I usually travel between 80 and 90mph on the highway and still seem to get the good mileage. I also am usually spirited while driving around town __________________ 2007 Z4 3.0si Coupe • 6 MT • Black Saphire Metallic • PP • SP 2016 GMC Sierra SLT Z71 Premium Plus 4x4 2017 Harley StreetGlide • Denim Black • V&H Tune 2021 BMW x30i • Phytonic Blue Metallic • Fully loaded
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06-03-2010, 04:49 PM	#8
dekaliber Major 74 Rep 1,143 Posts Drives: '07 Z4MC, '11 JCW, '18 Z06 Join Date: Mar 2008 Location: Los Angeles iTrader: (1)	By trip computer being off, do you mean whatever algorithm it's using is misreporting estimated range, mpg, average speed, etc.? I don't have enough data to say for sure on the M, but it hasn't given me a reason to doubt it. I kept a spreadsheet of each fillup and odo reading when I had the 3.0si, and I found it to be pretty accurate. Sadly, accurate would now mean a whopping 15.8 mpg combined (heavily local) on the M.
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06-03-2010, 05:14 PM	#10
scottyD Private First Class 2 Rep 136 Posts Drives: 07 3.0si Coupe Join Date: Oct 2007 Location: DC/Baltimore area iTrader: (0)	My computer is also very close - within a few tenths of a mile per gallon... 60mph cruise on flat roads (a/c off) gets you around 38 to 40 mpg in the 3.0si. I'm still amazed at the fuel efficiency of these engines.
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