Toyota Prius
Problems & Worst Years

Braking is the defining concern for the early Prius, and the 2011 model year makes that case emphatically: 407 total complaints, the highest volume in this batch, with six rated safety-severity. Brake actuator failure alone accounts for 76 reports and brake booster failure another 60, and a further 20 describe the brake pedal going to the floor during a braking event — collectively, well over a third of the year's complaints describe some form of the car failing to stop as expected. A secondary theme involves the engine consuming oil and running low on pressure (30 reports), plus 20 complaints about headlights failing frequently.

By 2016, the picture changes almost entirely. Total complaints drop to 87 and none are rated safety-severity, but a new and unrelated issue dominates: windshield cracking, both from minor impact (26 reports) and, more strikingly, without any impact at all (18 reports) — together more than half the year's complaints. Brake booster failure reappears in smaller numbers (8), alongside engine stalling during braking and general electrical system issues. Recall 18V579 is on file for this model year.

The shift between years is worth noting for a buyer: the 2011 Prius's brake concerns are serious and safety-rated, while the 2016 model's leading issue is a glass defect that, while inconvenient and costly to replace repeatedly, isn't flagged as safety-related in this data. A pre-purchase test should include a firm brake pedal check and a hard stop from speed regardless of year, and a visual check of the windshield for any prior cracking pattern on 2016 examples.

As with every year in this dataset, these are complaints owners chose to file with NHTSA rather than a controlled measurement of failure rates, so treat the totals as a guide to what's worth inspecting rather than a guarantee of what any specific car will do.