In theory, the slip at speed should be less than 3% even under a load. Any slippage results in heat which has to be carried by the cooling system. This is why most modern vehicle use some means to lock up the converter or direct couple the trans.

Dennis

----- Original Message -----
From: Allen Hill
Date: Thursday, January 11, 2007 5:15 am
Subject: Re: RPM?MPH
To: vanagon@GERRY.VANAGON.COM

> FWIW, I have always figured that due to the automatic vs.
> standard trans
> that the auto trans would need higher rpms for any given speed
> due to
> slipping in the torque converter and transmission.
>
> Route 66 Rider!
> Ramon Hill
> Live Long and Be Free
> =======================
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> Behalf Of
> Geza Polony
> Sent: Wednesday, January 10, 2007 8:20 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: RPM?MPH
>
> That's a higher speed than my '84--at 4,000 rpm I'm reading 60
> or close to
> it.
>
> The relationship between rpm and speed should be rock-solid unless
> something's slipping--either your clutch or your back tires, as
> on gravel.
> How old is your clutch plate?
>
> Vanagon speedo's are almost always optimistic. The Bentley says
> 8% higher
> than real speed is acceptable up to Dec. '84 IIRC, slightly less
> thereafter.Glad they weren't making moon rockets.
>
> Geza
>
>
> On Wed, 10 Jan 2007 16:28:31 -0500, Mike Stainbrook
> wrote:
>
> >HI All-silly question time:my late 85,with 4 speed stick,at indicated
> >3500 RPM,I get speedo reading of 62 MPH. is this about right?-is
> >freeway average,I get a little better down hill,little less up
> >hill..reason for asking is that the box seems to be a bit
> slower in
> traffic-clutch wear?
> >thanks Mike
>