Hi first time to the thread and I had a question?

First the story I was motoring one afternoon with my portable gps

and I found out that my speedometer was reading 75 and the gps was reading 70.

Now what baffled me the most was that I was running my stock tires?

Do all minis have this problem or is it gust my car?

 

Yes, your speedometer reads fast. Apparently it's required in Europe that the speedo read slightly fast (exact amount seems to be a topic of discussion.)

 

I've had 17 cars in 25 years of all shapes and sizes, and every one had a speedo (and ODO) that read 3-5% higher than the actual speed - and with stock tire size. It is the manufacturer's way to reduce litigation risk and ensure optional larger tires don't put you in a compromising position. I'm sure there are better reasons, but I believe nearly all cars come from the factory that way.

There are a number of ramifications - some advantageous to the manufacturers:
- warranty expires sooner
- mileage appears to be better

I use GPS as an indicator now.

Regards

 

According to prior threads on NAM (you can search if you want), in Germany it is illegal for a speedometer to read low so they are set to read high. The formula suposedly is:

R = Real speed
D = Displayed speed

D = R - ((0.1 * R) - 2.5) all im MPH.

 

I questioned this early on. On the MINI anyway, the speedometer and odometer are not tied together as they are on most other vehicles. So even though the speed may be wrong, the odometer is actually recording the proper distance driven.

Or so I was told...

 

Hmm, yeah I was wondering about that. I'm using a PocketDyno for measuring 0-60 times and its supposed to stop calculating when I reach 60mph, but I always need to get the speedo between 65 and 70 before it registers. Now I know why.

 

BMW odometers almost always seem to be dead on. Try this. Next time you are on a long road trip, look for highway signs with a distance of say a couple of hundred miles. Then check your indicated mileage and the road signs as you get closer to your destination. I have always found that my odometer is almost always dead on, and I could even tell that one of the signs approaching Boston was wrong.

(5% error of 200 miles is 10 miles.... so you would definitely notice if your odometer is 10 miles off at the end of the trip)

BMW speedometers always read high due to German regulations, but BMW odometers are much more accurate than that.

 

That’s not as true as you think.

My dad has a bmw m roadster and it also has a

5% arror on the speedometer.

 

5% on the speedometer, yes. Is there any error on the odometer?

 

not that i have discovered

 

I can verify what Katana states after driving 9,200 miles across country this summer. Every time I hit an "odometer check" on the highways, my 328i read dead on. I mean REALLY dead on! We even slowed down at the start and end of the 5-mile stretch to see where we lined up with the markers...dead on, I tell you!

However, the spedometer reads about 3 mph fast as measured simultaneously with a Garmin Street Pilot, Garmin Etrex Vista and a DeLorme Earthmate and the 328i's speedometer.

Theo 8^)

 

With my old BMW, I also used to set my OBC display to instantaneous speed. One way this could be done in the MINI is to find a flat stretch of highway and use cruise control. Then keep resetting your avg speed. If you set your cruise speed for right at 70mph, your average speed will probably display something like 68 or 67mph.

 

I recently took over a MCS (rescued you might say) and was ready to take it to the dealer for this very problem. Thanks for the insight everyone. My speedo reads anywhere from 5 to 7 mph faster than "average speed" on the on-board computer. I verified against our 2 other cars (both US made) and found this to be true - now I just don't look at the speedo, but look out for the highway patrol!!

---
Indi Blue, blue lapis, Federal SS595 tires, all else stock right now.

 

I tend to watch my tach. when motoring,I like a high reading speedo