Re: 164's AT SPEED, my story

[JALFAjr@xxxxxxx]

I don't know what the top speed for the 1991 164S' was supposed to be, but in
1993, my wife and I were in western Kansas on our way to Santa Fe, and we came
upon a long straight level stretch of deserted road in the late afternoon, and
I put my foot to the floor.  Before running out of acceleration room, the
speedo was reading 154 and still climbing, although very very slowly.  

Now, I know that Alfa's are notoriously optimistic on their speedos, (make
that all of the 14 Italian cars members of my family have owned) so the 154
MPH is suspect.  But since this was only the third week I had owned the car,
and hadn't had it out on the open road before, I had earlier in the day done a
speedo check using interstate mile markers.  I did this first at 60MPH and got
an actual speed of 57 MPH, so I said, AHA, 5% fast.  A litle while later, I
had enough clear road that I thought I would try the timing at 90 MPH and I
got an actual speed of 87 MPH, not the 85 I was expecting.   Taken together,
these seem to say that either the speedo is always exactly 3 MPH fast, or it
gets more accurate at higher speeds!  

Using the 5% correction, the actual speed at a 154 indicated was only 147 MPH,
or using the 3 MPH difference it was actually 151 MPH.  Either way, it was
fast.  (My personal selection is 151, but not just because it is faster, but
every test I did from 90 to 50 showed a 3 MPH difference, as opposed to a
percentage.   This included several of those roadside radar things that show
your speed as you go by.  (My current 95 Q  with the 215 Michelins reads about
3 MPH SLOWER than you are actually going at 50MPH.  I have not tested it at
other speeds with enough accuracy to say if it is always exactly 3 MPH over or
a percentage.)

John Justus 
1995 164Q (215/60-15 tires and a lower reading speedo than actual, radar
indication on Wednesday this week)
1971 1750 GTV (215/50-15 tires and at least a 10% optimistic speedo)

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