Date: Fri, 18 May 2001 03:27:41 +0100 From: Johannes H Andersen <johsnopsamsafish.com> Subject: Re: RMP to MPH ratio?
Mats wrote: > > On Mon, 14 May 2001 12:06:58 GMT, "Kyle Kontney" <themoznopsamr.com> > wrote: > > >Hello all, > > > >I have two SAAB 900S cars. They have a slight difference and was wondering > >if anyone could tell me if this is adjustable, or if this is normal. Please > >note: these are Automatic, not manual shift, 4-door non-turbo. > > > >The 88 900s gets better gas mileage, and the RPM to MPH is about half > >numerically. For example, if I am traveling at 70 MPH, my RPM is 3500. > > > >My 89 900s has a different ratio. For example, 70 MPH, my RPM is 3800. > > > >So I am wondering if there is something wrong? > > > >What is the acceptable RPM for the speed ratio? > > There is probably nothing wrong, the autotrans on those cars came in > three different gear ratios, I think that you can see what model of > transmission you have by looking at a small plate on the gearbox. > > On the classic 900 autos I have had, one did about 3000 rpm at 55 mph, > and another that did 2800 at the same speed. > > The one that did 3000 rpm at 55 mph had the same gear ratio that an > 4-speed manual had. The 5-speed manual was a little better, did about > 2400 rpm at 55 mph. > > /Mats Three speed automatics! That would explain the busy engine. Some time ago, I borrowed a 2.0 Ford Sierra automatics, three speed. I found the engine rather busy for a 2.0 at motorway speeds, but thought at the time that this was the price for the convenience of an automatics at city driving. Nowadays, we have 4 or even 5 speed automatics. Johannes