Re: Cruise Control speed setting 1 mph out.
Posted: Wed May 16, 2018 5:24 pm
No it's not related to tyre size. Mine is always 1mph over setting on cruise control. Either doing 40mph r 80mph. It is software related IMO. Can't understand why some are different to others tho. That's just strange.santa wrote: ↑Wed May 16, 2018 5:04 pmThe Optimum here in Scandinavia is the top spec with 18" wheels and there is No difference with My 16" winter wheels.Strangways wrote: ↑Wed May 16, 2018 2:54 pmSanta, I don't know what spec the Optimum is, but I would guess it has 16" wheels. All the people who say there HUD is showing 1mph faster have 18" wheels. The difference in the overall circumference is 1" bigger on an 18" wheel. If the speedo has been based on revolutions of the 16" wheel then the car will actually be travelling faster if it is on 18" wheels. 70 mph on the 16" wheels will equate to 70.8 mph on 18" wheels.
Has that solved it or did I guess wrong on your wheel size?
My Cruise control is spot on, only going up and down hills, will the speedo go over or under the set speed and pretty quickly find the correct speed again.
That's why I thought it might be the miles conversion that does it.
And the speedo is quite precise compared to the gps: 80 kmh on GPS is 82 kmh on the speedo/HUD on 18" wheels, on My 16" wheels it's more like 83/84 on speedo is 80 kmh on GPS.