Flat spots on all four tires

If a wheel drags you don't get a flat spot, you get premature wear. A flat spot, or more correctly a bald spot, comes from locking a wheel. Antilock brakes should minimize the risk of this, but hard braking can be hard on tires.

Tom

 

Some towing numbnuts probably dragged it onto a flatbed at
one point. Ask about its service history and how it got to the
shop if not under its own power on any occasion.
.
_H*

 

like they said above, the only way to flatspot a tire is to lock it up and skid (the only way for a malfunctioning brake to do that is if it locks up).

you can, however, cause tires to go out of round if you leave your car sitting still for a long time, but we're talking reallllllly long time. like years.

 

I'm going with hobbit's numbnuts explanation. Er. . . not meaning anything about hobbit, just that I think he is right that this probably happened when the car was dragged onto a flatbed tow truck.

 

It seems doubtful to me that a single 20' drag onto a metal flat-bed truck would cause enough friction to flat-spot all four tires. Maybe a drag down the block would do it, but 20'?

 

I saw two brand new airplane tires flat-spotted from landing with locked brakes. That must of been surprising.

Tom

 

No, this story doesn't add up. If the ABS is offline, the dash will light up and that is kind of hard to miss. It's also kind of hard to miss the effects of locked wheels

Back in the day, I've had to slam the brakes to avoid cars sailing through red lights or stop signs, and a few times for deer. You lock the brakes at highway speeds, there is no f***ing way not to know it

Plenty of sound effects and special effects, especially once you grind to a stop in a cloud of cooked tire rubber. Yes, locking all four wheels at highway speeds will flat spot them

But to not notice that you've locked all four wheels? Even assuming - however unlikely the case - that there is no dash warning of inopperative ABS?

Uh-uh

 

It it was a small plane, say a 150 or 172, that would be a good way to flip it over on landing

 

Cessna 150 with a nervous student pilot. The pilot was pressing hard on both pedals, inadvertently locking the wheel brakes.

When the plane taxied back to the hanger, it went "whump, whump, whump" as it rolled over the flat spots.

Tom

 

Lucky for the pilot that only the tires got flat spotted. Easy enough to replace tires

 

I'm going with the flatbed drag theory. The previous owner ran out of gas or killed the battery twice, had it dragged into a dealer both times, and then got disgusted with the car and sold it. I hope that you had a dealer thoroughly check it out at the last guy's expense before you bought it.

 

Why would the wheels lock up if you run out of gas? Or a dead battery?

 

Electricity is needed to move the parking pawl out of the way. Every Prius has an immobilizer - no power, you're immobilized. You'll run out of power shortly after running out of gas. Wheels won't turn when the car is dragged (mostly on pavement, not smooth metal) and tire tread wears away.

 

All the scenarios to cause this within 500 miles seem too unlikely for words. Even a brutal towing episode would affect two wheels, not four. This looks like a manufacturing/warranty issue to me.

 

After owning a towing company for many years, and having to drag a locked up vehicle on a flatbed on several occaisions, I can say for certain that a 20' very low speed drag up a bed will not cause noticeable flat spots.

 

That did not happen.

Here is how I managed to flat-spot all 4 tires, in the early 80's:

I was going around 70 mph near St George, Utah, when a guy in the breakdown lane suddenly pulled into traffic. I mashed the brake pedal in the '75 Chevy Monte Carlo I was driving, and all 4 wheels locked up

Lot's of nice sound effects from all 4 tires grinding into the Interstate. The driver of the other car appeared quite elderly and kept veering back and forth between the shoulder, the left lane, right lane, and back across to the left lane, as if thinking "why are all these cars behind me? Maybe I'll try to steer this way NO this way NO this way..."

I missed him by a coat of paint and rust, and had nice thump-thumps from underneath.

If the ABS isn't working, the dashboard lights up. If you had still locked up all 4 Prius wheels, you would have known about it from the sound effects.

It didn't happen

 

Maybe prior owner got the car in a sideways skid, taking ABS out of the equation.

 

Could be, what was the option package again? Did it have VSC?