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Why do hybrids get great city gas miles?

A hybrid badge on a vehicle
A hybrid badge on a vehicle

Saving money at the fuel pump is great, and hybrid vehicles are an excellent way to get more miles out of every gallon of gas. But what makes hybrids so efficient, especially when it comes to gas mileage when driving in the city?

For starters, know that hybrids use an internal combustion engine with at least one electric motor and a battery pack. The electric motor relieves the load on the gas-powered engine, which in turn helps improve fuel economy.

But not all hybrids are the same. There are variations and important things to consider for any car buyer considering putting a hybrid in their garage or driveway. You should consider what type of car you do the most. Then determine whether better mileage in the city or on the highway is best for your gas budget on the road.

Let’s start by looking at what drives hybrids and how everything from fuel economy to linear speed can get a boost from this automotive technology.

How do hybrid cars work?

Unfortunately, no mechanical blueprint covers today’s ever-expanding range of hybrid vehicles. What is easy to understand is that a hybrid generally provides better fuel economy than a vehicle that runs solely on a petrol engine. Credit goes to the hybrid’s electric motor and battery pack for those extra miles, especially when driving around town.

“Hybrids have better mpg in the city because of the slow speed,” explains Brian Moody, editor-in-chief at KBB.com. “The start-and-stop function allows the car to use the electric motor more. Most hybrids that accelerate slightly use the electric motor for the first few meters, then the petrol engine kicks in.”

The three main categories of hybrid cars are mild hybrid (MHEV), hybrid and plug-in hybrid (PHEV). Each helps to improve overall fuel economy. Some are better than others in terms of mileage over non-hybrid models.

Should I use EV mode?

The short answer is an emphatic “absolutely”. The goal of any hybrid is to put the electrical components to work and save money on gas. A hybrid powertrain does not require maintenance. If an EV mode is available, it’s a good idea to use it as often as possible.

“When driving in town or at low speeds, a hybrid makes the most of the electric part of the hybrid gas/electric setup,” says Moody. “For example, if you’re stuck in heavy traffic and crawling along, you’re mostly using the hybrid’s electricity.”

What can make the biggest difference in fuel economy is which type of hybrid powertrain boosts the vehicle you drive. For example, some hybrids can only run on electricity, while others can’t.

City mileage vs highway mileage: what’s the difference?

Hybrids improve mileage, although certain variations have an edge on city and highway fuel economy. Knowing which type of hybrid suits your driving needs is the best way to start car shopping.

A mild hybrid couples a gas engine to a small electric generator mated to a compact lithium-ion battery. This adds electrical assistance during acceleration and restarts the engine using a start-stop system. Unlike a hybrid or PHEV, an MHEV’s electrical power cannot fully power the vehicle, so the mileage gain is smaller.

Hybrids like the Toyota Prius use electric motors and battery packs that work with gas-powered engines and shared transmissions. A hybrid keeps its electrical system charged by using heat and energy supplied through regenerative braking when decelerating.

Hybrids can only drive electrically, often only at lower speeds and over short distances.

A PHEV has the same general layout as a hybrid. However, it comes with a bigger and more powerful battery pack. This allows a plug-in hybrid to go electric for 10 to 40 miles, depending on the make and model.

Unlike a regular hybrid, a PHEV must be plugged in to fully charge its battery pack.

How to get the best gas mileage for your hybrid car

Don’t worry, you don’t need to drastically change your driving habits or maintain a turtle-like pace to get the best fuel economy in your chosen hybrid. But if you’re determined to spend your life on the fast lane of any highway, the needle on your hybrid’s gas gauge will likely drop just as fast.

That’s because the drivetrain works harder to maintain speed, explains Moody. “At high speed, when the vehicle encounters more wind resistance, the gasoline engine turns more often to keep the vehicle at highway speeds.”

It’s good to know that many PHEVs can drive electrically at highway speed over limited distances. On the other hand, compared to a standard hybrid, the heavier weight of a PHEV powertrain can reduce fuel consumption in the city and on the highway once the battery pack is depleted.

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