Gareth wrote:waremark wrote:Mr Cholmondeley-Warner wrote:Watch the rev counter and the speedo, and see if they actually drop in exact proportion.
How could it be otherwise?
The speedo and rev-counter 'follow' since they're not direct mechanical linkages. If there are magnetic components, they are more likely to be less linear than if they are corrected by electronics, which probably introduce greater lag.
The chap who reverse engineered the VW ECU while looking at dieselgate said the rev counter display value depended on a large number of factors, only one of which was engine speed
(I think much of the fiddling was around the idle point so regardless of actual changes in engine speed due to load for aircon etc, the rev counter would show a constant, steady idle, which is apparently more reassuring to customers than telling them what the engine is actually doing).
I believe SWMBOs temp gauge on the Octy is much the same (ie very shortly after starting the car it sits perfectly in the middle, and I suspect would have to go outside a fairly wide range before reflecting this on the gauge). Apparently this is progress