Cruise control - wrong speed

[bulkier]

Hi,
I bought Peugeot 308 SW 2009. and I notice that my real speed is 5km/h less than what I set on Cruise control!

e.g. I set 85 km/h but my speedometer and GPS (app on phone) show 80km/h.

Does anybody had similar problem or have an a idea what could cause this problem?

Thanks!

[xantia_v6]

I think they all do that. The cruise control agrees with the speedometer speed, but both are 5 to 10% optimistic.

Unlike some other makes of car, I don't think that there is any way to adjust it.

[Hell Razor5543]

Something to remember is that all vehicles must NOT be travelling faster than the speed indicated by the speedometer (legal requirement in most countries). Most (if not all) manufacturers set their speedometers to show a speed slightly greater than the actual speed. That way the manufacturers are not liable if you get done for speeding slightly over the speed limit.

[bulkier]

Well I had same Peugeot but 2010 and cruise control and speedometer show same speed.
Now in this 2009. Peugeot, cruise control ALWAYS show exactly 5km/h more than speedometer!
And GPS phone navigation show same speed as speedometer.

It is just strange... I will get used to it but I would like to hear if anybody else have same problem...
And what is normal behaviour: should cruise control and speedometer show same speed?

I understand that everything can/is adjust a little bit less/slower... but why this difference?

[PaulC5]

If you have a code reader that does live data see what speed that shows. It might be the speedo needle has been moved on its spindle and not set correctly. On our C5 the needle came loose since it had cracked but I glued it back on but could have set it at any speed if not careful.

[GiveMeABreak]

It's normal for there to be a variance on most PSA vehicles. Mine also has a discrepancy between Cruise set speed and actual speed. This is by design and is usually preset in the BSI.

[GiveMeABreak]

I know that on the C5 X7 there's a tolerance set of 3 KMH, but on many later vehicles that parameter is automatic and no longer a variable in the BSI (non-configurable as it is not present).