What to do about the speedometer error in the BMW, any ideas?

I have a '03 525i and have noted an error of about 10-12%. When I'm going 75 mph on the speedometer, I'm only going approxmately 67 mph. I've checked on other BMW sites and everyone is having this problem. Why is this allowed? Has anyone been able to get this fixed? This adds 10-12% to the total mileage that is shown and for a lease vehical is could cost you some serious bucks.What to do about the speedometer error in the BMW, any ideas?Yes, this is a common problem among many BMWs and in fact is engineered deliberately to err on the side of caution. BMW USA wants to avoid lawsuits where people say "had I known I was going that fast, I would have slowed down and my injuries would not be so severe from that accident." It is harder to make such a claim if you were talking about "had I known I was going so slow..." When BMW errs on the side of cautoin, they are basically trying to avoid the above "type" of scenario. So, to some extend, the "error" is deliberate. However, if it is too off, and your car is under warranty, you can have your local BMW dealer replace the gauge cluster with a "hopefully" better calibrated gauge cluster speedometer.



That said, the problem is only apparent in the speedometer. It does NOT affect your odometer or tripometer. A relatively accurate speed signal is received from the sensor in your car's differential. The error is simply in the calibration of the speedometer to that signal. The accurate signal is used for your odometer, tripometer and trip computer (OBC). No worries about inaccurate odometer and "lost mileage" on your lease.



One way to get your accurate speed is to hold the car steady at a particular speed. Go to your OBC trip computer and reset the "avg speed". Since you're at a constant speed, the new "avg speed" reading will be your real speed at that moment. You will see that the speed signal is relatively accurate compared to what is shown on your speedometer.



Besides everything else above, you can throw off the accuracy of the speed signal with incorrectly sized tires/wheel combinations.What to do about the speedometer error in the BMW, any ideas?
They must have a recall if the problem is that prevalent check the dealership or consumer websites.What to do about the speedometer error in the BMW, any ideas?I would assume you do not have the stock tires on this car, BMW doesnt have errors in anythingWhat to do about the speedometer error in the BMW, any ideas?
Three points,

1. If your tyres are worn the speedo will over-read the true speed, the calibration is based upon a given size of wheel. Worn tyres are smaller and go round faster for the same speed on the road, the speedo can't compensate and shows a higher speed than the true one.

2. Most speedos are actually calibrated to slightly exaggerate your true speed this is to avoid problems with you inadvertently going over a speed limit and getting caught.

But it helps with bragging too, no one complains if their car goes faster than the maker claims, if it goes slower there could be trouble.



3. Don't worry about the mileage recorder it will usually be correct even if the speed reading is a bit high, but the same factor of worn tyres can affect this too.



Hope this helps.What to do about the speedometer error in the BMW, any ideas?bmw's have always read about 5mph faster than your really going. i think it is that way for most cars. make sure you have the right tire wheel size installed on your car.