RE: High RPMs at highway speed?

["Dan Sinclair" <sinclair@prospro.com>]

I too have wondered about this one.  I understand that a close-ratio gearbox
provides better acceleration and power, especially from smaller engines, but
I've always thought a taller 5th gear (or perhaps a 6th gear) would be a
welcome addition in my car.  Clearly, if you're driving the car hard and
fast, your typically using 2nd,  3rd and 4th gears anyway, so why not make
5th a true overdrive?  As it is in my 90, 5th is just a few 100 RPM taller
than 4th.  My girlfriend's '88 Accord, however, loafs at 55 in fourth and
absolutely lugs in 5th at 55.  She reserves 5th for interstate cruising at
70+mph, and even then she's only pulling 2,600 or so.   5th is a big jump
from 4th in her Honda.

When my parents bought their 4000 in 1982, we were told by the Audi dealer
(I know, lips moving - lies emanating...) that the European models had
taller gearing than the US models because the Germans believed that the US
market would never be driving over 55MPH by law, thus they maximized the
ratio for a limited spread, topping out at about 65.  My parents' 4000 was
in fact designated a 4000S-4E.  The 4E included a taller eurospec 5-speed
gearbox.  In fact, the '82 4000 had a much taller 5th gear than my '88 90
does now, and it was running a 1.6l 4 cylinder.  I certainly think my 2.3l 5
would be able to manage with a little taller gearing.  Can anyone confirm a
different gear ratio for European spec equivalents?

-Dan

Dan Sinclair
1988 Audi 90, 70K mi.
Walla Walla, WA (soon to be Portland, OR).
Pics&details: http://131.107.68.28/a4.org/registry/details.asp?car=761

-----Original Message-----
From: owner-quattro@audifans.com [mailto:owner-quattro@audifans.com]On
Behalf Of Clough, Samuel
Sent: Monday, June 07, 1999 5:01 AM
To: 'Audi Quattro'
Subject: High RPMs at highway speed?
Importance: High


Ok, so I've always wondered this, but I've never asked anybody and I figured
it was time to submit my question to the infinite wisdom of the list.  Why
do our cars run such high RPMs on the Interstate?  In the A6 at 80mph it's
turning 3,600.  Should you cruise around 90 (of course totally theoretical)
the RPMs are just about on 4,000.  None of the American or Japanese cars
I've ever driven turn anything like this.  Most of them seem to just be
getting to 3K at around 80/85. It seems to me that a German car designed for
the Autobahn would have a higher top gear.  If I drove this car like I
assume it was intended to be (ie Autobahn) and assuming the gearing between
USA and European cars is similar, I'd be cruising at or over 5k.  I mean how
long can the motors last being driven that way?  It just seems to me that
with the gearing on the car I'm putting unnecessary wear on the motor with
long highway drives.  Am I crazy, or are these cars so bulletproof that they
are immune to the wear affects of higher RPMs?
TIA,
Samuel
95 A6Q (loves the far side of the speedo)

Samuel W. Clough
INVESCO Retirement Plan Services