I just read this... I think we have the same issue...

 

Nope. Mine's 2 mph off.

 

Ok I get it that the digital readout of the speed does not match the GPS always, but does the distance traveled match the GPS? THAT is what is important. Most speedometers have a few accurate points and a lot of inaccurate points ..... especially the old magnetic drive cabled speedometers. Next time I am on the PA Turnpike I'll check mine against the mile markers.

 

Driving through a "speed check" machine in a 40mph zone, I slowed until it read 40. At that point, my speedo read 36, and I thought wow, one of those it pretty off.

After picking up a Garmin Nuvi 660, I found, like many of you, that the car speedo seems off. One thing that's odd to me, though, is that it is not a percentage error. My GPS reads 40 while my speedo reads 37. However, at 80 on the GPS, the speedo reads 77, as oppossed to the 74 that you would think it would say. Always off by 3mph.......

 

Well, according to the Utah State Trooper who ticketed me last Wednesday, my speedo is right on the money. :impatient

 

My answer is "yes". See my post above..

 

This is the printed information I received from the dealer in Indianapolis.

Subject: Maximum Permissibloe Speedometer Error
Models:

 

This is the printed information I received from the dealer in Indianapolis. It is dated May 1996 from Woodcliff Lake, NJ-Product Enginnering

Subject: Maximum Permissible Speedometer Error
Models: All
General Information: A certain amount of "speedometer advance" is necessary to compensate for negative tolerances in tire diameter, electronic controls, and other factors. This advance reduces the risk of the speedometer displaying a speed that is less than the vehicle's actual speed.

The amount of speedometer advance can be calculated by inputing a frequency (using the DIS Tester, "Kombi Test Schedule") that corresponds to a given speed and noting the speed that is indicated by the speedometer. The maximum permitted speedometer advance is 10% of the actual (input) speed plus 2.4 mph.

Example:
Actual Speed = 50 mph
50 mph x 10% = 5 mph; 5mph + 2.4 mph = mph
There fore, the permissibloe displayed speed is 50 to 57.4 mph

(Note: the displayed speed must never be less than the actual speed).

No repairs should be attempted if the speedometer advance is within 10% + 2.4 mph.

NOTE: The amount of speedometer advance has no effect on recording of accumulated mileage in the odometer display. The odometer records total mileage digitally and does not incorporate any "advance" tolerances.

Warranty Status: Information

.............................End of Document ..........................
So ... do the math when you drive the Mini and don't do the math when you drive anything else.

This is the best we can get from one of the finest automobile manufacturers in the world?

Does this sound like BS to you?

When my office remodeling is done (a couple of days) I will scan the document and try to post it.

 

That's crazy to be so far off. Someone should come up with a circuit that goes in line with the speedometer and allows the owner to dial in a correction factor.

From what I've read, they've done the same thing with the water temperature gauge (it doesn't show actual values within a certain range.) I wonder what else they've dumbed down.

 

"I wonder what else they've dumbed down"

Obvisously us for one thing! Guess we are going to need a top watch to see where we really are at an indicated 60mph. Any know what the + or - is of a gps unit??

 

I've been told by several sources that if you have at least 3 satelites, a GPS is extremely accurate. This includes an instructor at a coastal navigation class.

It is good to know that the odo is independent of the speedo for warranty reasons (assuming we can believe them), and to allow us to accurately calc our fuel consumption.

 

Attached is answer from Product Engineering in Woodcliff Lake, NJ

What do you think?

 

I finally got to test my speed against a Garmin GPS. It's only 2 mph slower than indicated. I guess all those cars hurrying to get in front of me are getting their rocks off passing a MINI!!