Speedometer Error

[Andre]

Has anyone verified their speedometer?

I have a Canadian model ZHP. The speedometer reads about 3.5Kph too high (about 2.2 mph). I suspect this is because of BMW Canada "cheaping out" on the gauges - i.e. they have used the regular 330i gauges due to the metric readings. I'm wondering if they did not take into account the slightly different rear-end ratio.

BTW, I verified the reading with two GPS receivers. When the speedo says I am going 100Kph, I am actually going about 96.5.

No big deal I guess, but it means my odometer will show higher than actual mileage.

 

[Zchild]

I've had my speedometer checked after a received a traffic ticket. I thought I would have a stronger leg to stand on during the legal proceedings with a report in hand. As it turned out my bimmer was precisely on point. I thought with larger wheels just maybe my speedometer would have been slightly effected, however after speeding $200.00 US, The service I paid found no derivation. Mine is US spec... purchased in Europe and shipped back to the US. Happy Motoring...
[driving2]

 

[tazza0712]

There has been a lot of talk about BMWs and most "luxury" cars having incorrect speedos, there have been articles in 'Car and Driver' but I don't have the links right now. They claim that BMWs have the most innacurate speedos with a deviation of up to 4% - you are normally going slower than what the actual speedo says. Take this as a good thing, the likeliness of sitting on the speed limit and being booked for speeding is reduced. Car watching out for driver's wallet??

 

[bmwrocks]

On my X5, I have verified that the speedo shows about 5 mph greater than actual speed. I did this by driving in a convoy with communication and asking what speed we were traveling at various points in time. Interestingly, the BC shows the correct speed. I showed this particular anomaly by resetting it while on cruise control and it shows 5 mph less than the speedo.

BTW, my 330 shows very close to the true speed on the speedo.

 

[Bmw 325i 7803]

I think this was brought up before, and the general consensus was that this was actually a good thing... I'm not complaining.

Actually this does not mean the odometer shows higher than actual mileage, since the computer is correct, the needle is not.

 

[Andre]

I think this was brought up before, and the general consensus was that this was actually a good thing... I'm not complaining.

Actually this does not mean the odometer shows higher than actual mileage, since the computer is correct, the needle is not.

Unless, in my case, all calculations are based on a normal 330i rear differential. The ZHP has different gearing.

 

[tazza0712]

I was paying attention to my speed a lot more today, and I realise that it does feel a lot slower than my previous car, and I also get a lot more tail-gaters, presumably because when I think I'm sitting on the speed limit, I'm actually doing under...?? I'm confused. Oh well, maybe it's just my imagination.

 

[Bmw 325i 7803]

Unless, in my case, all calculations are based on a normal 330i rear differential. The ZHP has different gearing.

I highly doubt BMW would fail to compensate for the ZHP's different gearing, even my car shows me going 2-3 mph faster than I really am going. This is done intentionally by BMW. You seem to be set on proving BMW made an engineering error...

Try the BC buttons instant speed calculation like suggested above.

 

[Andre]

I'll try the BC test.
I'm not set on proving anything - I was just wondering if others had the issue.

Remember, BMW "cheaped out" on my gauges to save making ZHP gauges for Canada. (They also show a 6500RPM redline). It's quite conceivable that they cut corners on the programming too.

 

[jonaphn]

i've been wondering how i've been going 200 MPH down the freeway. hm.