Can someone enlighthen me as to why most Ferraris have thier speedometer on 20km/h when lieing idle?
Many, many Italian cars have traditionally had tach's and speedo's whose needles are stopped from going all the way to 0. It's just the way they are.
It's not just F that do this, most modern cars truncate the low end of the speedometer (on my '89 Honda they very cleverly labeled the 5 mph needle position as "0" so it looks like the needle is resting at "0" when it really isn't). The reason that they don't/can't use the very low end of the speedometer is that modern cars measure the rotation of a multi-pole magnetic ring for determining speed. At very low speeds, the errors in the angular relationships between the magnetic poles (and their resulting field) cause the measurement to "bounce" (At high speeds, the system is counting many revolutions of the ring so a small error in any one pulse gets averaged out to nothingness). For example, if one of the magnetic poles is shifted a little towards the previous pole that also causes the pole after the shifted pole to appear a little late -- so the speedometer might me reading 4 mph, 6 mph, 5mph, 5mph, 4mph, 6 mph, 5mph.... Is this your biggest problem in life ...
You are correct about the current cars but the Italians have been doing it since at least the 30's that I know of.
I'd just give them credit for being honest sooner -- older mechanical systems suffer from the same "bounce" effect at very low speeds due to the non-constant frictional losses appearing as a greater variation in the whole.
