I have 205/50/16 tires and aftermarket wheels on my 2011 R56S. Stock was 195/55/16. Even with the stock tires and wheels, the speedo was off by 4 MPH at 50. 50 indicated is registered as 46 MPH on roadside speed warning signs, without fail. Same with my current setup. Sooo...4 MPH off at 50 would indicate 8 MPH off at 100, right? At 100, that would be an 8% difference. So I assume that when my odometer gets to 100k miles, that I have actually put only 92k miles on my MINI. Or am I missing something here? My MINI racks up enough miles, without getting 8k added over 92k of driving. Any math majors want to help me out on this one? MINI dealer has told me that no fix exists for the speedo error.

 

The speedo is deliberately set high by BMW/MINI in the software. It does not affect the odometer, which is accurate.

It seems that a new thread is started on this same topic every week.

 

+1.

I think it's a product of handheld navigation units and phones with nav apps that display gps mph that get everyone asking. Although I already knew the technical aspect of how BMW mini read and display miles per hour and odometer readings I find myself verifying the difference when on an empty road using cruise control. As others my car displays 3 or 4 mph higher then gps mph in fact all my cars do. MINI. BMW and MAZDAS

ITs no big deal but if it's your first time lease and you got a 10k a year plan I guess one could feel like they are getting cheated.

There are more important things to worry about in this day and age.

As always. Your mileage my vary (YMMV). Ha Ha. lol.

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Laws make it illegal for auto manufacturers to install speedometers that register less than the actual speed but allows them to install speedometers that are up to 10% over the actual speed. It's not hard to figure out which way they're going to go.

 

Different tire sizes do alter the facts by a bit. To know for sure what difference it makes use this calculator:
http://tire-size-conversion.com/spee...r-calibration/

 

 

and this topic comes up often, google is your friend.

 

Made me go look. I've got 68 links to MINI and general automotive websites all relevant to MINI stuff, all collected after several years of need and blatant curiosity. SOOPERCOOPERINFO.com, which is currently off line but expected to return fairly soon, is a huge data base of MINI resources consisting of thousands of links all categorized. All it takes is a little patience to do the research and record where you find the good stuff.

 

The Internet Wayback Machine has SCI archived:

https://web.archive.org/web/20140110...ooperinfo.com/

The speedo thing is very well known. If you can read the OBD2 bus (e.g., with a ScanGauge, UltraGauge, or app like Torque) you'll see that the speed the car thinks you are going is a lot closer to actual road speed. It definitely is affected by tire size, though.

 

Thanks, guys. I will check that tire size/speed change calculator. But it is the same difference as it was with the stock tires. Not fully understanding how the odo could be correct, even if the speedo isn't. Guess it's in the software, as stated. I was mostly concerned with the odo being accurate, so no worries. Could a programmer go in and "adjust" the software to make the speedo more accurate? Maybe when I am getting a tune?

 

It's not a mini thing. It's federal law in the US. All cars have this accuracy issue.

 

I checked the tire size/speed difference link. It shows only a 1.5 MPH difference between my stock tires and my new ones at 100 MPH. So...195/55/16 to 205/50/16 is not very much of a change.

As far as all cars having this issue, not the cars I work on for a living! They have Certified speedos, as they are Police Interceptors. Tested and re-verified/certified once per year. I really don't think I am asking for a LOT here...just for my speedo to be more accurate than 8 MPH fast at 100 MPH (92 actual indicated as 100). I really hope there is something that can be done with software changes. Maybe I am nuts, but I think with all of the technology in modern cars and thier design, the speedo should be a no-brainer to get right. My 67 Chevelle is off on the speedo quite a bit, but she is highly modified, so I kinda expect that. But...I can simply change the speedo drive gear in my Chevelle in order to get the proper speed reading, if I wanted to. The ramblings of a simple man. Humor me some. It's the small stuff that drives me nuts. LOL!

 

There is an adjustment available in NCS Expert programming. See post #4: https://www.northamericanmotoring.co...ml#post3546148

 

I believe that's for the digital display only, the analog dial is not changed.

The BMWWhat app for Android and iOS also has this setting.

 

From line 10 on that spreadsheet:

"Will make the speed on the tach more correct instead of 2-7 MPH faster than actual speed if set to nicht_activ."

 

I was surprised to see it was so far off, I bought a 2012 R55 a few weeks ago and this was my first road trip 4 hrs. long, with my GPS, and yes at 75 mph the speedo and tach both showed 79 mph, B.S.. One would think that this should not be an issue with all the technical crap in the car, and how can you be sure that the odometer is accurate. I guess I will have to check that aspect, but wont be easy due to the digital system, any suggestions

 

Like others have said. The MPH difference isn't a mistake. It's built in on purpose for various reasons So the digital age has nothing to do with it.

Checking your odometer is EASY and very analog. Go to your nearest highway and rest your trip odometer on one of the mileage posts. They are supposed to be exactly 1 mile apart. Do this a few times at different spots on the hwy just to confirm.

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I rent cars every week and run my GPS in all of them. Every rental speedometer runs 3 to 5 mph faster than my GPS regardless of make and model.

 

It was only when GPS devices became common place that the public understood that the speedometer on their cars read low.

At least when pulled over for speeding you can honestly say "No officer, I really don't know how fast I was going."

If it really bothers you then code it out like mentioned above.

Edit: removed duplicate information.

 

Ya, I checked it today on the HWY, and the odometer part is correct. I have and old Opel that is the same way, but it is more like 10% off, 70 mph = 77 on the speedo. I just didn't expect it to be 4 to 5 mph off being new, heck my 05 Jeep GC was only 1 to 2 off at hwy speed.

 

According to my opinion The speedo is deliberately set high by BMW/MINI in the software. It does not affect the odometer, which is accurate.

 

Even with the odometer, "accurate" is relative. The diameter of the OEM tires vary by size and change by another half inch or so as the tread wears down.

 

i have found motorcycles to have same error over actual speed. Kaw's and BMWs. My R55S
seems to be near 10% over? Or else I drive close to 90 a lot, alone with other interstate traffic?