335is speedometer running 3 mph faster

SilverII · 10-05-2010, 06:35 AM

Anyone else notice their speedometer showing 3 mph faster when compared to a gps?

michaelthepsycho · 10-05-2010, 06:38 AM

My 335i runs 4 mph faster than the Garmin. Usually manufacturers put "happy" speedos but who really knows which one's correct, eh?

serg1282 · 10-05-2010, 06:40 AM

As far as I've read it's done intentionally for legal reasons. Better to over-report than under-report speed.

Eights-n-Aces · 10-05-2010, 06:53 AM

It must be Tuesday. Time for the weekly "Dude, my speedo is reading fast" post.

anerbe · 10-05-2010, 08:51 AM

^ haha, this question has been popping up for years.

To account for different wheel/tire packages, etc... BMW does this to ensure their vehicles won't be liable for conservative speed readings.

Officer, I didn't know I was going 75 - my car is telling me I'm only going 68.

Blubaron79 · 10-05-2010, 09:56 AM

This has been talked about countless times on here. It's normal..

Tom K. · 10-05-2010, 10:17 AM

Quote:

Originally Posted by Blubaron79

This has been talked about countless times on here. It's normal..

True, but be aware that it varies with diifferent individual cars. I've had BMWs with the typical 3~4% error and some which were accurate within 1%. The OBC seems to give an accurate reading if you don't have a GPS.

BTW, it tends to be worse with BMW motorcycles. My '76 R75/6 was 20% optimistic at 100 mph.

Tom

jopa489 · 10-05-2010, 10:25 AM

Quote:

Originally Posted by serg1282

As far as I've read it's done intentionally for legal reasons. Better to over-report than under-report speed.

Correct. Strict EU regulations state that a vehicle can NEVER under-report the speed, regardless of what wheel/tires might be on the vehicle. To account for every situation, BMW offsets the speedometer display intentionally. This does not effect the odometer, since the car does know the true speed (as indicated by the poster above who correctly stated true speed can be seen in the OBC hidden menus), it's just factored into the speedometer gauge itself.

However, why BMW doesn't take this out for US-spec cars is beyond me.

MusclezMarinara · 10-05-2010, 10:27 AM

"Dont beat a dead horse when its down" RE POSTED

e90prelci · 10-05-2010, 12:20 PM

indicated speed and actual ground speed in different. the GPS is correct.

Express · 10-05-2010, 12:28 PM

Quote:

Originally Posted by Eights-n-Aces

It must be Tuesday. Time for the weekly "Dude, my speedo is reading fast" post.

HAHAHAHAHAH

10-05-2010, 06:35 AM	#1
SilverII Colonel 40 Rep 2,334 Posts Drives: '11 335IS Join Date: Jun 2010 Location: DFW iTrader: (0) Garage List 2011 BMW 335IS [9.66]	335is speedometer running 3 mph faster Anyone else notice their speedometer showing 3 mph faster when compared to a gps?
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10-05-2010, 06:38 AM	#2
michaelthepsycho Lieutenant Colonel 76 Rep 1,644 Posts Drives: 11 Montego Blue E90 335i Step Join Date: May 2009 Location: CA iTrader: (4)	My 335i runs 4 mph faster than the Garmin. Usually manufacturers put "happy" speedos but who really knows which one's correct, eh? __________________ Former car 2011 BMW 335i Step - Montego Blue / Chestnut Brown
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10-05-2010, 06:40 AM	#3
serg1282 First Lieutenant 72 Rep 333 Posts Drives: through Join Date: Jul 2009 Location: NJ iTrader: (0)	As far as I've read it's done intentionally for legal reasons. Better to over-report than under-report speed.
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10-05-2010, 06:53 AM	#4
Eights-n-Aces []D []-[] []_[] []< []\[] []_[] '][' 27 Rep 418 Posts Drives: 335i Convertible/Le Mans Blue/ Join Date: Dec 2009 Location: Weston, FL iTrader: (0) Garage List 2010 335 Convertible [0.00]	It must be Tuesday. Time for the weekly "Dude, my speedo is reading fast" post. __________________ 2010 E93 335i M LeMans Blue 2001 E 46 330ci Coupe/silver/black/Sunroof 1999 BMW R1200C Cruiser-Ivory & Blue
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10-05-2010, 08:51 AM	#5
anerbe Lieutenant Colonel 121 Rep 1,568 Posts Drives: Red E90M 6MT Join Date: Dec 2006 Location: BH, MI iTrader: (2)	^ haha, this question has been popping up for years. To account for different wheel/tire packages, etc... BMW does this to ensure their vehicles won't be liable for conservative speed readings. Officer, I didn't know I was going 75 - my car is telling me I'm only going 68.
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10-05-2010, 09:56 AM	#6
Blubaron79 Brigadier General 1435 Rep 4,724 Posts Drives: 2021 M340i xDrive Join Date: May 2009 Location: PA iTrader: (0)	This has been talked about countless times on here. It's normal.. __________________ Current: 2021 M340i xDrive Previous: '18 340i xDrive; '15 335 xDrive; '14 435i xDrive; '09 335 E92 xDrive
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10-05-2010, 10:27 AM	#9
MusclezMarinara Banned 262 Rep 5,018 Posts Drives: VALNCYA Join Date: Jan 2009 Location: Jersey iTrader: (23) Garage List 2011 BMW 1M [9.22] 2009 335i Sedan xdrive [9.34]	"Dont beat a dead horse when its down" RE POSTED
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10-05-2010, 12:20 PM	#10
e90prelci Private First Class 35 Rep 185 Posts Drives: 2007 e90 335i Join Date: Feb 2010 Location: socal iTrader: (6)	indicated speed and actual ground speed in different. the GPS is correct.
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