What is EFI? Understanding Electronic Fuel Injection’s Benefits

Vanguard EFI Engine

What is EFI? The short answer is Electronic Fuel Injection. But you probably didn’t come here just to figure out what the acronym stands for. So let’s look more closely at what it is and why EFI is important for the small engines you find on generators, mowers, and other equipment. Understanding the benefits of electronic fuel injection can help you decide if the additional cost makes sense on your next zero-turn, generator, or other purchase.


What is EFI?

Electronic fuel injection replaces the need for a carburetor that mixes air and fuel. EFI does exactly what it sounds like. It injects fuel directly into an engine’s manifold or cylinder using electronic controls. While the auto industry has been enjoying the technology for decades, it’s not as common in smaller engines.

Vanguard EFI Engine

What are the Advantages of EFI?

Easier Starting

How many times do you go to start your generator by adjusting the choke first?

You won’t have to worry about that with electronic fuel injection. It works for both hot and cold starting, eliminating one of the major headaches of using small engines.

Automatic Altitude Adjustments

As you move from the 100′ elevations here in Central Florida to the mile+ elevations in the Rockies, you need to adjust the fuel/air mixture to keep an engine running well. EFI does that automatically through its electronic controls.

More Consistent Power

Thanks to the electronic controls that EFI offers, your generator engine is constantly running at its most advantageous throttle and air mixture settings. With the electronics doing the work, you never have to wonder if you have everything set just right. You’ll be getting consistent power and peak horsepower levels where they should be without any guesswork.

Better Fuel Efficiency

Electronic fuel injection improves your engine’s fuel efficiency. It’s not uncommon to see claims of 25% improvement here. That’s good on two levels. First, you’re spending less money on gas – a big deal for Pros that rely on a generator day in and day out.

The second benefit is that you’ll have to refill the tank less frequently when you’re asking your generator for more watts. This might only save you a trip or two during the day, but you’ll appreciate the reduction in productivity interruption.

Briggs & Stratton Generator

Fewer Emissions

Since EFI engines deliver air and fuel with better accuracy than a carburetor engine, they generally produce fewer emissions to go along with the improvement in fuel efficiency. Atomization of fuel also helps burn the fuel more completely.

Less Maintenance

Question – what’s the most common maintenance you’re performing on your generator?

If you’re an occasional user, chances are your generator ends up in the shop for a carburetor cleaning or replacement more than anything else. For Pros that rely on a generator more frequently, it’s likely oil changes, spark plug changes, and filter cleanings (all of which are easy to do yourself). No matter which boat you’re in, there’s no carburetor to maintain.

EFI does a better job of avoiding fuel gum up as well. Since the injection process atomizes the fuel, it burns more completely without leaving behind the residual fuel that a carburetor does.

What are the Downsides of EFI?

The main difference you’ll notice out of the gate is that EFI is a more costly system than a carbed (carbureted) engine. If your budget allows you a choice between the two, the advantages are worth it in my book.

Looking further down the road, there are potentially higher repair costs. Electronic fuel injection is a more complex system. When something goes wrong with it, it’s likely going to be a more expensive repair.

Vanguard EFI Engine

Special thanks to Jim Cross from Briggs and Stratton’s commercial division for providing insight into this article. Check out their Vanguard engines to see what the company is doing with respect to small engine technology.

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