speedo drive

[nistri]

Hi Colin,

According to contemporary road tests run by Quattroruote magazine on different Fulvias, the speedo is usually overestimating the real speed by 7 % in practice regardless of the absolute speed value or the type of instrument (Jaeger or Veglia). Several Fulvia owners have (even recently) confirmed with accurate timing that this is still the case despite the passing of many years.

Curiously (and unrelated to this thread and section) the speedometer of the Appia was thought by contemporary reviews to be exceptionally accurate and I can say that at least for my car it is still the case now.
Best regards
Andrea

[ian]

When the holiday traffic quietens down, I will have a test with a borrowed sat nav

[ColinMarr]

Thanks Andrea,

I had guessed this might be the case, but I didn’t want to hear it! I would have preferred my speedo to be accurate. I suppose I will just have to drive 7% faster to compensate!

Best wishes,

Colin

[YKR 567J]

And then there's the weakening of the spring as they get older, causing them to over-read even more. I'm afraid I don't have my LHD HF any more (how do I go about changing my forum name, by the way?) but its kilometric speedo was wildly optimistic. From memory, a true 70mph/113km/h corresponded to an indicated 130km/h/81mph.

I thought my car unexpectedly rapid when I bought it - after all, it made enough noise for the indicated speed to be convincing - but plugging in a Road Angel told me the truth. The error increased proportionally as speed rose, the one I've just mentioned being about 15 per cent but at 31mph or 50km/h it read 55, so 'only' 10 per cent out. The odometer was about 10 per cent adrift too, strangely, even though the car was on the right 175/80 R14 tyre size. All those HFs on lower-profile, smaller-diameter tyres you see must have speedos which portray pure fiction. I wondered about trying to find some sort of speedo drive gear which would make the odometer accurate and thus bring the speedo somewhere near reality, but never pursued it.

John

[fay66]

Hi John,
Sorry to hear you no longer have the HF.

To change your any of your details click on 'Profile' at the top and you should be able to modify from there.

Brian
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