IMA versus HSD: The Honda Accord hybrid versus the Toyota Prius

As the Accord hybrid is just days from officially hitting the market, what are the main differences between these hybrids?

Is one a Honda and one a Toyota, and that is really the main difference?

No. Both Honda and Toyota have been leaders in hybrid technology, but they have taken different paths.

The Honda Accord hybrid is built, like the Civic hybrid, on Honda's Integrated Motor Assist (IMA) system. A simple system, Honda sandwiches an electric motor between the traditional engine and transmission. Additionally, the Accord offers VCM, or variable cylinder management. Thus, fuel can be saved by reducing the gasoline engine, deactivating one or multiple cylinders, and relying more on the electric motor.

The electric motor of the Accord hybrid receives it's energy from deceleration and breaking which recharges a battery to power the electric motor.

The Honda Accord hybrid; however, cannot run fully on the electric motor alone.

Toyota's Hybrid Synergy Drive (HSD) is a more complex hybrid powertrain than the Accord hybrid. With a unique, more efficient gasoline engine and planetary automatic transmission, the Prius can accelerate from rest to 30-plus mph on electric power alone.

This feature allows the Prius to run solely on electric power during traffic or stop-and-start driving. Thus, especially in traffic and urban driving, the Prius is much more fuel efficient than the Accord.

On the highway; however, the Accord hybrid is more in line with the Prius, though it offers a speedier drive than the Prius.

More information on hybrid cars.