Just curious. Whenever I go by a radar sign it says I am going 5 MPH slower than what the speedo says.

I just tried a portable NAV and it reports the same thing.

Is this something I should have taken care of at a MINI dealer or is this just a cruel way to get us thinking we are going fast?

Edited: if this is the case does this mean I am racking up miles faster than I need to since I assume the Speedo is tied to the odometer?

 

This is par for the course for many cars, includint the MINI.

 

The speedometers in just about all cars and motorcycles are a little bit "optimistic". I've never heard an official reason for this, but the cynic in me just figures the manufacturers are trying to avoid a class-action lawsuit in case a bunch of people got speeding tickets and their speedometers were shown to be reading too slow.

 

I guess I should have mentioned that my 30+ year old porche had the same issue but I thought it was because it was old. They are off by almost exactly the same.

 

you can either get your speedo to be right or your miles to be right but not both.

 

Didn't I hear somewhere that BMW sets their speedometers at +3MPH?

 

Note that there are tire size options on the MINI. The tires change but the speedo doesn't. My regular tires seem to be about 2-3 mph off at 55. I'm not sure of my winter tires yet but it seems like 4 or so. By the way, the radar signs seem to be pretty consistent but not always right.

 

I've heard of the speedometer reading fast on purpose and it sounds really stupid. I'd love to have my speedometer calibrated to read correctly. I don't know how they operate, but I bet it is just a software value that could be changed. Heck, I'd even sign a waiver saying that I am an adult and can deal with knowing my real speed .

This "speedometer reading fast" sounds as goofy to me as buying a watch that can only be set 5 minutes fast to help you not be late for appointments. Come on! ... and what makes it worse is they don't even give proper divisions on the speedometer for us to compensate for the speedometer "error".

Ok, I'll go take my medication now

 

You can change it yourself if you want...


I broke down my speedometer once because I was playing around with different face place colors. I had to take the needle off, and if you don't put it back in the right place (like me the first time), the speedometer will be way off. My speedometer was reading about 20MPH off my actual speed when I first put it back together. I fixed it, of course .

Using the same logic, one could easily break down the speedometer and move the needle slightly to represent your actual speed.

Then again, I have the MINI NAV in my car, so I do NOT have the digital readout of speed. I guess you couldn't really do anything about that...

 

i think it's normal. and similar to that of tire pressure gauge biases if
the gauge is consistent and you know where you're at, you'll know wat
to do.

 

I have found this on mny cars but always on eurpean cars. I got cursious once as to why and was surprised what I found out in my research.

Apparantly, at least in Germany most likely all of europe, the car compnies are heavily fined for each car they build that the speedomeer goes over the speed limit by even one mile per hour. Cars are sampled at random from the production run as well as jsut speedos themselves.

The thing is it doesn't matter if the speedo is for a european car or an export they will be fined if they are off.

What the companies have done to protect themselves is made it an industry standard that all speedos are calibrated to 5mph (or whatever equivelant kph) to keep from having this to deal with.

 

This thread was interesting to say the least. I never thought about my speedometer to be "off". I'll have to have someone follow behind and tell me what speed they were doing to keep up with me....Hummmm, maybe the next state trooper I pass will oblige me.

 

That would be a nice trick but what is to say the person following you does not have the same problem?

 

Yep - the "chase car" will almost certainly have the same problem. The best way to check your speedometer is with a GPS unit that displays vehicle speed. I think most of the Garmin units are accurate it 0.1 MPH.

 

So, do you think the milage reads accurately, but the speedometer is off? If the mileage and spedo read fromt eh same place, does that not mean that the car actually has less miles than reported? It would suck to be over say 1,000 miles on a lease when it was overestimating milage by 2000.

 

BWM is notorious for speedos that read higher than actual MPH. I think this is a safety feature. BMW knows that we all drive 10 MPH above the posted limit, therefore by having a speedo that reads 5 MPH faster than true speed, we are only 5 MPH over, and in most situations, within the margin of error for radar cops, ergo no ticket.

 

Well, the error is usually a percentage of indicated speed, and is generally less than 5%. So if both the speedometer and odometer were inaccurate by that same amount, it would take 40,000 miles of driving before the odometer would be off by 2,000 miles.

In most cases, though, the odometer and speedometer are calibrated individually. In the older cars that have cable-driven speedometers, the odometer is driven directly off of the cable through a series of gears, while the speedometer needle is driven by a spinning magnet. That's how you calibrated the speedometers in the older cars - by moving the magnet closer to or further from the needle. Doing this left the odometer calibration unchanged, since it was gear-driven.

With the newer vehicles that use electronic pickups to sense wheel speed, I believe that that speedometer can still be adjusted without throwing off the odometer, which is generally pretty accurate from the factory.

 

I wonder the exact same thing about my MC every time I drive home. I guess it's normal. I always pass the speed check point at around 40mph and the sign indicates I'm going 35mph. It's nice to know it's a normal occurance and not some oddity that's proprietary to my MC. lol

 

It is a conspiracy to end your warranty coverage 3,000 miles early

 

8-10mph off. That's what I discovered after my wife followed me home off the lot in Spike and I couldn't figure out why she was going so slow. She was wondering why I was in such a hurry. So I set the cruise on my Titan at 70mph and she was doing 60mph according to her speedo. I know my Titan is dead on do to previous encounters with Mr. Radar gun.

 

This is so true, mine is off by 5mph and I figured it was because it was a BMW. This means, of course, that when I was doing 80 and it felt like a cloud I was actually only doing 75..... guess I'll try again just keeeding!

 

I bumped an old thread because I found an answer that may help others.

My speedo is not off a percentage. It is off by 5mph no matter how fast I am going. At 35 it reads 30 and at 75 it reads 70. I've tested it with my GPS and Speedview (Android App) with the results being identical.

So my speedometer is coming apart and I am finally going to be able to tell my speed without doing math. Yay.

 

My 2010 is off by a percentage of about 6% compared to my Garmin.

 

My 2 cents:

I've compared the reading on my MCS with both my Garmin, the portable radar display our county sherriffs keep moving about for our convienence and against the Prius and I consistenly get a +3 MPH difference on the MCS. But in my opinion (unfortunately not shared by our local law enforcement) speed limits are mearly suggestions!

 

Posted by MatI think that the troopers are merely suggesting the posted limits. Nevertheless, they maintain the option of speeding citations for those who don't accept their suggestions.