Volt and Prius Debunk Myth That Hybrids Have “Twice the Problems of Battery-Electric Vehicles”
In our reporting on electrified vehicles of any type, be it a hybrid-electric, Plug-in hybrid-electric, or battery-electric vehicle, one common comment from readers is this: “Hybrids and plug-in hybrids have all the problems of an ICE vehicle along with any issues a BEV might have.” A second common comment is that “Since ICE vehicles have a thousand times the moving parts of a BEV, they have many more repair and maintenance needs.” We exaggerated a bit on that second comment, but you get the idea.
HEV - Hybrid-electric vehicle. Such as the Prius Hybrid. Such vehicles can travel short distances on electricity alone and normally use their electric drive to augment the gasoline engine’s abilities.
PHEV - Plug-in hybrid-electric. These vehicles have an electric drive system capable of operating in EV-only mode for as many as 50 miles before reverting to hybrid drive.
BEV - Battery-Electric Vehicles, or “battery-only.”
ICE - Internal combustion engine. The word “vehicle” is often dropped. For example, “driving ICE.
Electrified Vehicle - Any vehicle that has an electric drive. Including HEVs, PHEVs, BEVs.
Theory - Simple Machines Are More Reliable
As an engineer by education and former employment, the idea that a more complex machine would be less reliable is easy to grasp. I get it. More stuff, more stuff to break. However, engineers also learn to “test the theory.” We decided to do just that.
Most Reliable Vehicles Are Hybrids
We considered which electrified vehicle has the best body of reliability data for us to consider. The slam dunk answer is the Prius Hybrid. This car has been around longer than the modern age of battery-electric vehicles. There is an abundance of reliability data from which we can gauge if a car that can propel itself using only electricity for short stretches but can also act as a hybrid vehicle using its internal combustion engine really is more unreliable than a battery-electric vehicle.
We first turned to Consumer Reports. There is no better warehouse of automotive reliability data. Consumer Reports uses owner-reported data to rank how well a given model and model year vehicle performs in many ways. Most notably, reliability. Consumer Reports uses a 1-5 scale with 5 being the best possible reliability score.
When we researched the Prius we found that it has an unbroken streak of perfect reliability from 2009- 2021. The Prius earns a 5/5 from Consumer Reports for each of those years. 12 consecutive perfect years. The Prius Prime plug-in hybrid-electric vehicle is a special trim of the Prius. It has earned a 5/5 reliability score from Consumer Reports every year it has been built from 2017 to 2021. "The Prius is a regular among our most reliable cars, and this is because it is a Toyota, which tends to be toward the top of our brand reliability rankings," said Steven Elek, Senior Automotive Data Analyst at Consumer Reports.*
Toyota also scores highly on the J.D. Power Vehicle Dependability Study (VDS). This study ranks vehicle brands by the number of defects owners of three-year-old models report. Toyota makes a mix of vehicle types and has the highest number of electrified models and the highest number of unit sales of electrified vehicles in America. Notably, Toyota has had no battery-electric vehicles for sale for the past three years. Toyota ranks near the top of all brands, and its Lexus division, again, a leader in hybrid vehicles, is number one.
The Least Reliable Vehicles Are ICE and BEV
Using the same data, it is apparent that Tesla’s battery-electric vehicles are last in terms of both Consumer Reports rankings and also close to last in overall brand reliability rankings. Tesla’s highest-scoring vehicle is the Model 3 and it only earns a ⅗ from Consumer Reports.
The Chevy line is the most interesting. Consumer Reports has good data for the Volt PHEV, the Cruze ICE, and the Bolt BEV. Looking at the data, it is clear the Bolt is tops. However, the Volt does quite well. Look beyond the data to recent news and we feel the Bolt is disqualified. A very large percentage of the Bolts made are being recalled now for the third time and many are having complete battery replacements due to ongoing fires.
Honda Makes PHEVs, ICE, and HEV cars, all from a similar template. In the Honda line, both the HEV and PHEV cars earn perfect 5/5 ratings and the ICE car is lower at 3.5.
Why Are PHEVs and HEVs More Reliable - An Easy Answer
The reason that HEV and PHEV vehicles are more reliable despite seeming more complex is simple. They are not more complex. Modern HEV and PHEVs eliminate many of the most common ICE vehicle failure points. Many have no timing belt, no accessory belt, no starter, no alternator, and many other pain points have been modernized. For example, spark plugs are now a once-per ownership change, and not expensive. All vehicles now use electric steering. And HEV and PHEV vehicles also have regenerating braking systems that reduce brake maintenance - just like BEVs.
Conclusion - Theory Is Not Yet A Predictor Of Reliability
Clearly, a future of simpler vehicles holds promise. However, Toyota, Chevy, Honda, and other brands have already proven that HEV and PHEV vehicles are already more reliable, and in fact simpler in some ways, than old-school ICE vehicles. Tesla has been in business for 18 years and has models with ten-year reliability records. Yet, the BEVs from Tesla consistently score low on reliability studies. Which of course, are answered by Tesla owners.
There are many great reasons to buy a battery-electric vehicle. They are fun to drive, they are much quieter than conventional cars, and they save owners money on energy costs, as well as repairs and maintenance. However, as today’s PHEVs and HEVs have proven, these advantages are not unique to BEVs and in fact, the other green vehicle styles may have an edge in some areas. Notably reliability.
*The quotation from Consumer Reports was added shortly after this story's initial posting.
John Goreham is a long-time New England Motor Press Association member and recovering engineer. John's interest in EVs goes back to 1990 when he designed the thermal control system for an EV battery as part of an academic team. After earning his mechanical engineering degree, John completed a marketing program at Northeastern University and worked with automotive component manufacturers, in the semiconductor industry, and in biotech. In addition to Torque News, John's work has appeared in print in dozens of American newspapers and he provides reviews to many vehicle shopping sites. You can follow John on TikTok @ToknCars, on Twitter, and view his credentials at Linkedin