My second OEM HVAC blower is starting to whine after only 3.5 years in service, so I thought I'd test one of the aftermarket blowers from Amazon. I measured the power consumed on HI, and the difference was substantial. The OEM blower draws 215W, and the $35 Amazon blower draws 116W. The power draw was also lower at each of the lower settings. My guess is most of the aftermarket ones are similar. It was subjectively hard to tell how much difference there was in the airflow, but it was definitely some.

On the plus side, the aftermarket blower has the cutouts needed to fit the '03, even though it was marketed for 04+. I buy the 2004+ blowers and cut out the plastic channel to fit the '03 (or swap the motor to the '03 housing) instead of spending the extra $100 or more that the '03 blower commands.

So for now I put some lithium grease into a hole I drilled in the bottom of the OEM housing, and we'll see how long that stays quiet. I'm really bummed that this Toyota blower had problems after 3.5 years when my first one lasted 19.

If you want to measure how much air the blowers are moving you can copy what drone and AC aircraft pilots do to measure propeller thrust. Just find a scale that can measure in grams (or fractions of an ounce), hold the blower a fixed distance from the scale, and see what the scale reads when the blower is on. If you repeat the test the same way with both blowers the results should be accurate enough to compare the blowers to each other.