Odometer Speed vs GPS Speed - United Bimmer Community

**kvadgama** · 11-04-2006, 08:49 AM

I'm not sure which speed is correct.
I put my car in cruise at 70 mph and also have my GPS on.
GPS indicates that i'm going 65mph whereas odo is right on 70mph.
Any thoughts?

Thanks

K

**celsdogg** · 11-04-2006, 09:31 AM

BMW speedometers are about 6% optimistic.

**defkon99** · 11-04-2006, 09:58 AM

COULD IT BE that your tires are bigger ?

drz · 11-04-2006, 10:48 AM

BMW speedometers are a few mph fast. Use your trip computer to determine your actual speed.

By the way, the odometer is the display with the numbers that tells you how many miles your car has traversed.

DEATH2000 · 11-04-2006, 02:02 PM

Quote:

Originally Posted by celsdogg

BMW speedometers are about 6% optimistic.

Why is that?

drz · 11-04-2006, 03:58 PM

It is to ensure that people do not violate speeding laws as a result of their speedometer. I think many manufacturers do this.

**xsperf** · 11-04-2006, 09:17 PM

^^ wtf, really? why the hell do manufacturers care? if 90% of speeding tickets are a result of BMWs.. hell thats popularity!

**celsdogg** · 11-04-2006, 10:09 PM

Quote:

Originally Posted by DEATH2000

Why is that?

i dont know, but I read it from Mike Miller, from Bimmer Mag and have read it several other places.

its interesting to note that i have found that it is true in both of my bimmers.

while my wife goes 75 down the highway in her subaru, both bmw's read 80.

**Rooz** · 11-04-2006, 10:44 PM

Quote:

Originally Posted by defkon99

COULD IT BE that your tires are bigger ?

That has a LOT to do with it...

**xsperf** · 11-04-2006, 10:53 PM

Quote:

Originally Posted by celsdogg

i dont know, but I read it from Mike Miller, from Bimmer Mag and have read it several other places.

its interesting to note that i have found that it is true in both of my bimmers.

while my wife goes 75 down the highway in her subaru, both bmw's read 80.

lol wat if teh subaru is wrong

**mullethunter3** · 11-05-2006, 12:09 AM

i pass "radar shooter thingys" at what my car says is 40 and the read out isdf 37. so, i go by that... i guess.

**celsdogg** · 11-05-2006, 09:44 AM

Quote:

Originally Posted by xsperf

lol wat if teh subaru is wrong

it was the same way with her jetta.

nick_318is · 11-05-2006, 08:02 PM

I have also done what Amanda has done and I almost always end up going faster on the odometer then the radar says.

**215BIMMER535** · 11-05-2006, 08:12 PM

i noticed that from day one with my car, oh well, if you know the amount to adjust for actual speed who cares

**celsdogg** · 11-05-2006, 10:37 PM

^^^ i take it as it is. kinda keeps me safe

from the law. . .