# Trip through southeast usa



## Flyingman (Sep 13, 2009)

Snipe656 said:


> Strange that when I log my daily trips in do not detect odo reading differences between my cars. Now I want to actually pay attention to it to see if the BMW is off.


I think the garmin GPS is pretty dam accurate. And if one is off they are all off since they are using data from same satellites.

That said, I noticed that my mph were approx 3mph slower on the gps than the Odometer/Speedometer on the car. This was true unless I was going slower, in the 40mph range it is only about 2mph off.

I know there is an entire discussion about this somewhere on this forum.


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## Snipe656 (Oct 22, 2009)

The discussions I have read on it say the speedo is off on purpose but the odo is correct. I will just have to pay attention now. I know three days out of the week if all I do is go to work and back that it will be 89 miles. But most my driving the past couple of months has included side trips. It has been 89 miles in a number of cars though so now curious if it is in this one too.


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## Flyingman (Sep 13, 2009)

Snipe656 said:


> The discussions I have read on it say the speedo is off on purpose but the odo is correct. I will just have to pay attention now. I know three days out of the week if all I do is go to work and back that it will be 89 miles. But most my driving the past couple of months has included side trips. It has been 89 miles in a number of cars though so now curious if it is in this one too.


Actually, I will have to double check the Odo. I was assuming it was off like the Speedo. The MPG is definietly off like the Speedo, reading approx 5% better than actual.


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## Snipe656 (Oct 22, 2009)

I always reset my mpg, average speed, and trip odo on the car with fillups then I record on my phone the miles traveled based on the odo(not the trip one) to give me my mpg for that tank. The number reported by the car and what I do "on paper" are usually pretty close to one another but never exactly the same although not off by 5% since that would mean a tank the car said was 28mpg would be something like low 29s? I am definitely not seeing that big of a difference between my numbers.


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## Flyingman (Sep 13, 2009)

Snipe656 said:


> I always reset my mpg, average speed, and trip odo on the car with fillups then I record on my phone the miles traveled based on the odo(not the trip one) to give me my mpg for that tank. The number reported by the car and what I do "on paper" are usually pretty close to one another but never exactly the same although not off by 5% since that would mean a tank the car said was 28mpg would be something like low 29s? I am definitely not seeing that big of a difference between my numbers.


Which supports my theory that both the speedo and the odo are off by the same amount of error.

I just did a 3,000 mile trip and my Avg MPG was shown in the 33mpg range. The actual was something near the 31mpg range.

It's possible I have made an error in adding up the gals I used, but the gps definitly confirms that my speedo is off by 5% on the high side, so it is only logical that everything else driven by that output like mpg, avg mph, odometer, etc... are all off by the same % error.


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## Flyingman (Sep 13, 2009)

Oh, by the way. If I lived in an area of the country with poor quality roads, I would most likely not have sports package suspension and high aspect ratio wheels, or I would definitely take out the insurance on those. Man, some of those roads are down right rough.

I am blessed with very good roads where I drive here in South Florida! :bow:


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## Snipe656 (Oct 22, 2009)

I just checked and back last fall when I used my 335d for daily driving I have numerous 89ish mile round trips. All of those were recorded using the cars odo. That is the amount of miles I have recorded in several other cars for this trip over the past 6 years that I have been doing it. I do not have a gps to compare things to but find it odd I would get the same basic number with the odo in so many cars if this one is off.


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## csecard (Oct 17, 2009)

Flyingman said:


> Which supports my theory that both the speedo and the odo are off by the same amount of error.
> 
> I just did a 3,000 mile trip and my Avg MPG was shown in the 33mpg range. The actual was something near the 31mpg range.
> 
> It's possible I have made an error in adding up the gals I used, but the gps definitly confirms that my speedo is off by 5% on the high side, so it is only logical that everything else driven by that output like mpg, avg mph, odometer, etc... are all off by the same % error.


I've checked my odometer with the GPS and they are identical. The consumer protection people comedown hard on the car companies when the warranty is up faster than it's supposed to be. Just ask Acura.

The speedometer is off and it drives me nuts.


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## wxmanCCM (Feb 17, 2010)

Just got back from a trip from East Tennessee to Western New York and back. 1461.1 miles on 38.8 gallons = 37.66 mpg. Speeds ranged from 70 to 85 mph (wife tends to drive 80-85 mph; I tend to stay within 5 mph of the speed limit).

Got somewhat better mileage on our return trip (38.8 mpg) than the trip going there (36.7 mpg), probably because we got stuck in a traffic backup near Pittsburgh in which we went about 5 miles in an hour and 15 minutes.


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## Flyingman (Sep 13, 2009)

wxmanCCM said:


> Just got back from a trip from East Tennessee to Western New York and back. 1461.1 miles on 38.8 gallons = 37.66 mpg. Speeds ranged from 70 to 85 mph (wife tends to drive 80-85 mph; I tend to stay within 5 mph of the speed limit).
> 
> Got somewhat better mileage on our return trip (38.8 mpg) than the trip going there (36.7 mpg), probably because we got stuck in a traffic backup near Pittsburgh in which we went about 5 miles in an hour and 15 minutes.


Well, I must be doing something wrong then. I was expecting around 36mpg as advertised.

I did see some of these numbers during certain segments, but overall it was down in the low 30's.

Still enjoyed the ride though!


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