Most common 2018 Toyota Prius problems
Share of the 37 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Toyota Prius complaints by model year
Best Prius years: 2021, 2020, 2018. Years to avoid: 2011, 2010, 2007, 2006, 2008. Compare all years →
2018 Toyota Prius recalls (1)
Electrical system › Wiring
Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain 2016-2018 Toyota Prius vehicles. A portion of the engine wire harness connected to the hybrid Power Control Unit (PCU), could contact the cover at this connection and wear, causing an electrical short circuit.
Remedy: Toyota will notify owners, and dealers will inspect the engine wire harness assembly and replace it if damage is found. A protective sleeve or protective tape will be included to prevent any future damage.
NHTSA defect investigations
Federal safety investigators have looked into a possible defect involving the 2018 Toyota Prius:
Pedestrian alert sounds
NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles.
What 2018 Toyota Prius owners say
Windows, wipers & sunroof
Was driving around 35 mph and my right side mirror blew up. The back blew off and the mirror was shattered and hanging. Nothing hit it. Contacted Toyota and the parts have been on a stop, but there is no recall. It has been 4 months.
The car is inadequate in the winter. When it snows I can't keep the windows clean. They changed the fittings and I can't even put winter blades on the car. Also, and this applies to almost all new cars as well, the LED lights freeze over. It's a safety hazard not to have lights that work. And it's a safety hazard to have to get out of the car in dangerous conditions to try and scrape ice off the windows and lights. The front and rear lights get caked with ice and snow. This picture is of my windshield after an hour of warming up. The wipers stay caked with ice. And when I turn them on, this is what happens. They smear the windshield with ice. They smear it with water too. I can't squeegee water with ice. I'd love to trade it in, but everyone has LED lights. They're a safety hazard. And these issues are keeping me from buying a new car. …
Engine & cooling
The contact owns a 2018 Toyota Prius. The contact stated that while driving at an undisclosed speed, the engine constantly overheated. An unidentified warning light was flashing on the instrument panel. An independent mechanic inspected the vehicle and became aware that the coolant reservoir was empty. One month later, the same failure reoccurred. A second independent mechanic inspected the vehicle, and the coolant reservoir was empty. The vehicle was taken to a dealer. The dealer diagnosed the vehicle with a coolant leak into the head gasket. The dealer advisor referenced a customer satisfaction program as the cause of the failure; however, the vehicle was over the mileage limit for the program. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 188,000.
The contact owns a 2018 Toyota Prius. The contact stated that while having a routine oil change, the contact was made aware that there was no coolant in the coolant reservoir. No warning lights were illuminated. The contact was constantly adding coolant to the coolant reservoir; however, the following day the coolant reservoir was empty. The failure had occurred on several different occasions. The vehicle was taken back to the residence. The vehicle was not diagnosed or repaired. The contact researched and was made aware of TSB Number: 013519; however, the VIN was not included. The manufacturer was notified of the failure. The failure mileage was approximately 89,100.
Lights
The automatic high beams will occasionally fail to operate and are stuck in low beams until about 2 minutes have passed, or until the automatic high beams switch is turned off to disable the system. This seems to be a software issue, as it seems to occur when an approaching vehicle passes by with bright lights. When this happens, all high beams are disabled for a couple of minutes, even if the high beam lever is switched to low beams and back to high.
Both taillamps holding moisture. Could cause electrical issues or fire. .. same year and model car have same reported issues and were fixed by manufacturer. This vehicle is the same but different level.
2018 Toyota Prius engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 1.8L 4-cyl hybrid | CVT | FWD | 58 / 53 / 56 |
EPA ratings. Class: Midsize car.
Frequently asked questions
Is the 2018 Toyota Prius a good car?
Based on 37 owner complaints filed with NHTSA, the 2018 Prius rates better than average: 85% fewer complaints than a typical year of the Prius at the same age. It is one of the best Prius years by this measure. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2018 Toyota Prius?
The windows, wipers & sunroof — 6 complaints, 16% of all complaints for this model year, most often about rearview mirrors/devices › exterior. Next are the engine & cooling (5) and lights (5).
How many recalls does the 2018 Toyota Prius have?
There is 1 recall for the 2018 Toyota Prius, the most recent from September 5, 2018 (wiring). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Toyota Prius?
The best years by complaints, compared at the same age, are 2021, 2020 and 2018. Years to avoid or approach with caution: 2011, 2010, 2007, 2006 and 2008. See the full Toyota Prius years comparison.
At what mileage do 2018 Toyota Prius problems happen?
The median mileage reported in complaints is about 10,000 miles; 80% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.