BBC has a post on the insight that the benefits of a hybrid are dependent on the use, location and driving patterns.

Hybrid cars are good for the environment, right? Their ability to switch to battery power means more miles to the gallon, and lower greenhouse gas emissions.

These things are true, however recent research suggests that preciselyhow green hybrid vehicles are may depend on traffic levels, road design and, perhaps most intriguingly, national driving styles. It also shows these vehicles provide significantly greater environmental benefits in cities in India and China, where there are hardly any hybrids, than they do in places like Tokyo and Los Angeles, where they are most common.

What is funny that the BBC positioned this paper as research was needed. If you ask the question of when will you use the electric battery system. When accelerating, braking, and at rest, then the answer is kind of obvious. if you drive consistent highway miles the electric battery system is going along for the ride with a weight penalty.

When the computer generated vehicles were “driven” according to the real world driving data, the hybrids generated fuel savings of 48% in India and up to 55% in China, compared with around 40% in the US.

Why the discrepancy? At low speeds, such as found in many cities, the internal combustion engine is inefficient, and so in the hybrids the electric motor took over. Energy recovered through regenerative breaking – when the electric motor is allowed to run backwards as a generator when the car is slowing – was, as expected, the main reason why they hybrids were much more efficient.

The second most important factor surprised the researchers. “We forgot about the aggressiveness of the driving styles,” says Gopal. “Dense traffic and aggressive driving styles favour hybrids.”

In India and China, driving involves a lot of accelerating and braking – which can both be done more efficiently with an electric drive train versus a petrol engine.

ExtremeTech provides a perspective for gas vs. hybrid vs. diesel.

Here’s the broad answer: Go with gasoline if you’re a low-mileage driver, hybrid for city driving, and diesel for high-mileage (mostly highway) driving.

The mainstream gasoline engine is best if you drive less than 7500 miles a year because the savings on fuel won’t match the premium you’re likely to pay for a hybrid or diesel car.Hybrid is the winner if you cover a lot of miles in stop and go city driving or on clogged expressways, where braking recharges the battery that powers the electric motor. It helps if you’re easy on the throttle and brake early and smoothly in a hybrid.

I drive 3,000-4,000 miles a year so gas is my option.