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 take a closer look at what it is and why EFI is important for the small engines you find in generators, lawn mowers, and other equipment. Knowing the benefits of electronic fuel injection can help you decide if you need to pay extra for your next zero steering, alternator, or other purchase.
Table of contents
- What is EFI?
- What are the advantages of EFI?
- easier to start
- automatic height adjustment
- More stable power
- better fuel efficiency
- less emissions
- less maintenance
- What are the disadvantages of EFI?
Electronic fuel injection replaces the need for a carburetor to mix air and fuel. EFI is exactly what it sounds like. It uses electronic controls to inject fuel directly into the engine's manifold or cylinders. While the auto industry has enjoyed the technology for decades, it's uncommon in small engines.

What are the advantages of EFI?
easier to start
How many times have you started your alternator by adjusting the choke first?
You don't have to worry about electronic fuel injection. It's good for both hot and cold starts, eliminating one of the major pain points of using a small engine.
automatic height adjustment
As you move from 100 feet of elevation in central Florida to over a mile in the Rocky Mountains, you need to adjust your fuel/air mixture to keep your engine running well. EFI does this automatically through its electronic controls.
More stable power
Thanks to the electronic control provided by EFI, your alternator engine always runs at its most favorable throttle and air mix settings. With electronics, you never have to wonder if everything is set up just right. You'll get consistent power and peak horsepower levels without any guesswork.
better fuel efficiency
Electronic fuel injection improves the engine's fuel efficiency. It's not uncommon to see claims of 25% improvement here. This works well on two levels. First, you spend less on gas—a big deal for professionals who depend on generators day in and day out.
A second benefit is that you don't have to top up the tank as often as you ask the generator for more watts. This may only save you a trip or two during the day, but you'll appreciate fewer work interruptions.

less emissions
Because EFI engines deliver air and fuel in a more precise manner than carbureted engines, they generally produce fewer emissions, improving fuel efficiency. Atomization of the fuel also helps to burn the fuel more completely.
less maintenance
Question – What is the most common maintenance you perform on your generator?
If you use it occasionally, your alternator will most likely end up in the shop for a carburetor cleaning or replacement rather than anything else. For professionals who rely on the generator more frequently, oil changes, spark plug changes and filter cleaning may be necessary (all of which are easy to do yourself). No matter what boat you're on, there's no need to maintain your carburetor.
EFI is also better at avoiding fuel sticking. Because the injection process atomizes the fuel, it burns more completely without leaving residual fuel like carburetors do.
What are the disadvantages of EFI?
The main difference you'll notice at first is that EFI is a more expensive system than a carbureted (carburized) engine. If your budget allows you to choose between the two, the advantages are worth it in my book.
Going forward, repair costs are likely to be higher. Electronic fuel injection is a more complex system. When something goes wrong, repair costs can be higher.

Special thanks to Jim Cross from Briggs and Stratton Commercial for his insights into this article. Check out their Vanguard engine to see what the company is doing with small engine technology.