When my front heater blower worked, it really only seemed to make a difference when I was sitting still or driving 35 MPH or less.  My blower motor fried recently, and I have not replaced it because I have noticed that at cruising speed (anything above 40 MPH) the fresh air blowing in is at least as powerful as the blower fan was.  I am not saying that is how it is SUPPOSED to be, but that's how mine is\was. FWIW.
Peace, John Baker

On Mon, 14 Jan 2002 08:38:25 -0600 Chris Stann <ChrisS@INFORMS.COM> wrote:

This Sunday I spent 10 hours dismantling the dash, adding insulation,
reconditioning the air flaps in the air box and replacing my dead heater
blower motor.  Yes, I put it back together.  I'll have pics coming too.

Now that the blower motor is working I noticed that the air speed, or the
force of the air coming out of the vents is rather disappointing.  At the
highest speed it seems equivalent to driving at 25 MPH with air flaps open.
Considering it's the same blower as the one in my rear A/C unit, I expected
an air blast, rather than an air breath.

How's yours?  How would you describe your heater blower performance?

Chris.