Toyota is facing numerous accusations that its 2013 Prius model cars are causing fuel economy to drop by 5 miles per gallon in city driving after undergoing recall to fix the car’s hybrid electrical system. The contention of users prior to the recall and subsequent repair is that the electrical system is prone to overheating and frying itself.
The repair became even more controversial than the problem it is trying to fix amid further allegations that the electrical systems are still overheating even after the system fix. Now comes the even bigger problem of fuel economy drop.
Close to 800,000 Toyota Priuses in the U.S. were recalled in 2014 in an attempt to address the overheating problems. A lawsuit filed last year by one of Southern California’s largest Toyota dealers, Roger Hogan, alleged that the software fix did not address and solve the overheating problems that usually result to an abrupt loss of power. The National Highway Traffic Safety Administration is also now reviewing the related complaint by the dealer.
Independent academic experts say that it is likely that the software change reduced the car’s fuel efficiency. A class lawsuit brought this month in federal court forwards the allegation that Toyota “concealed from consumers that the software reflashed decreased the fuel efficiency- defeating the very purpose of owning these hybrid vehicles."
Experts who are also hybrid vehicle engineers at major academic research centers said that Toyota’s documents show that it modified not just the software that controls the inverter’s function, but also the software in the vehicle’s powertrain control computer that determines how much power is supplied to the transmission by the gasoline engine and by the electric motors.
Experts further explained that the inverter boosts the car battery’s 200 volts to about 500 volts for the electric motors and converts the battery’s direct current to alternating current. When the brakes are applied, the power flows in the other direction to charge the battery.
Experts said Toyota’s modification reduced the power being supplied by the battery and in the process, increased reliance on the Prius’ four-cylinder gasoline engine. That is the reason, still according to experts, why the car’s fuel economy possibly dropped and its emission increased.
Toyota did not respond to the issues when confronted by the media. It only said that it is ready to defend itself from the allegations hurled against them.