I was stumped by that as well, especially since the Prius sold in Europe and Japan has 4 wheel disc brakes. And I have had some rear brake lockup/squeal when I've had to panic stop with the prius. It's just a short lockup and skid, then it seems to regain control. Never had that happen in any of my 4 wheel disc brake cars.DuncanNixon2004 said:Does anyone know why the Prius has front disc brakes, but rear drum brakes?
I assume that disc brakes are more efficient, possibly lighter, and maybe even cheaper. They're a proven technology. My '77 Mercedes has 4 wheel disc brakes.
Japanese 2004 Prius comes with rear drum brakes.Jonnycat26 said:I was stumped by that as well, especially since the Prius sold in Europe and Japan has 4 wheel disc brakes.
I don't agree this.DaveinOlyWA said:if your brakes are dragging, then disc brakes have a much smaller surface to drag on and would create less friction, not more.
I think, if that were the case, people would be replacing disc brakes every few hundred miles, or the pads would be a few feet thick.ken1784 said:I don't agree this.
I believe the pad is always touching to disc to produce friction, and the drum brake can be free from the friction.
Does anyone have any comments?
I'm not saying discs are cheaper than drums.DaveinOlyWA said:if you dont think drums are cheaper than you have never done a brake job on your car then.
You can't extrapolate this way... see below why.I don't have info concerning rear shoes but conventionally there seems to be a 3 or 4 to 1 ratio on replacement of shoes so extrapolation puts the Prius shoes needing checking at 450,000km and replacing at 600,000km!
Regen braking has nothing to do with rear brakes, since it doesn't involve brakes at all but only electric motors, which are linked to the front wheels. So the answer is : 100% front, 0% rear. And that's why rear brake shoes should last approximately the same as in other cars.Maybe regen braking is easier to engineer/implement? What's the percentage of regen coming from the front, if any, versus the rear?