2.3 L 4-Cylinder: Fluid Economy & Ford's Solution

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When Ford needed a fuel-efficient engine worthy of the Mustang name, the company chose the 2.3L Eco-boost engine, but did it accomplish what Ford intended?

The 2.3 L Eco-boost is a turbocharged four-cylinder engine used to power various Ford Motor Company cars, SUVs, and trucks beginning in 2015. First appearing in the Lincoln MKZ, the engine is known for appearing in the Ford Mustang primarily, producing 310 hp and 320 lb-ft of torque.

As Ford Motor Company unveiled its sixth-generation Mustang in 2015, the Detroit automaker gambled on a new design and an even newer engine to power its pony car sales. Ford’s new 2.3L Ecoboost engine development would offer great potential because it was cheap to build, had excellent fuel economy, emitted less pollutants, and produced enough power to be worthy of a Mustang pedigree. Coupled with the fact that heavy-handed Chinese tariffs on V6 and V8 engines had hampered Ford for years, the company banked on its new four-cylinder to pave the way in an emerging international Asian market. While many wondered how a four-cylinder engine could ever be good enough for a Mustang, the little powerhouse proved itself more than capable, and soon, Ford was using the turbocharged motor in more than just its iconic sports car. Today, Ford counts on the 2.3L Ecoboost to power some of its most popular vehicles. Let’s look at this little engine that has risen above its potential to see how Ford used it to revolutionize its sales and appeal to a new generation of buyers.

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What is An Ecoboost Engine?

EcoBoost is the name for Ford’s family of turbo-charged, direct-injected engines that power various models in their lineup. Introduced in 2009, the engines are designed to provide similar power outputs of much larger displacement engines but with better fuel efficiency, less greenhouse gas emissions, and cheaper production costs. For Ford, the technology was a four-leaf clover, checking all the boxes it needed to compete in an ever-changing global marketplace.

Ford introduced the 2.3L Ecoboost initially in the Lincoln MKC and, shortly afterward, in the 2015 Mustang. The engine had found its way into the high-performance Focus RS and other Lincoln vehicles within a year.

Over the years since the first Ecoboost engine was released in 2009, the engines have been offered in various displacements, from a three-cylinder 1.0 liter to a 3.5 V6 engine. Ford uses a form of technology on its entire lineup, from the smallest Fiesta to the largest Expedition. Ford felt that the Ecoboost was a more versatile way of accomplishing their goals than any diesel or early hybrid technology modifications might offer. It is considered to be one of the best production engines ever.

The Features Of The 2.3L Ecoboost Engine

The 2.3L Ecoboost engine and the second-gen 2.0L Ecoboost are produced in Valencia, Spain. While both engines share a similar bore size of 3.45 inches (87.55 mm), the 2.3L has a longer 3.70-inch (94 mm) stroke compared to the 2.0L (3.27 inches - 83.1 mm). The engine uses a reinforced aluminum engine block with aluminum alloy heads to reduce weight but with more significant oil passages and main caps than its smaller sibling. With a forged steel crankshaft and high-density steel connecting rods, the engine features aluminum alloy pistons with steel piston ring carriers and low-friction coatings. Internal oil jets coupled with large oil and cooling passages help increase the lubrication at the bottom of each piston, drawing from a deep sump oil pan and powered by a chain-driven oil pump.

The 2.3 L 4-cylinder is a double overhead cam motor with chain-driven camshafts, an aluminum cylinder head, and high-strength alloy pistons. Each of the four cylinders has two valves, one intake and one exhaust, with the intake valve of 32.5 mm (1.259 inches), which it shares with the 2.0L Ecoboost. Ford designed larger exhaust valves of 30 mm (1.18 inches) and fashioned the integrated exhaust manifold with three high-flow ports to improve airflow for the twin turbocharger.

Ford designed the engine with its Ti-VCT (Twin Independent Variable Camshaft Timing), giving the engine the ability to advance or retard the timing of the intake and exhaust valves independently of each other. The result is additional torque (especially at lower rpms), increased fuel economy, and lower emissions.

A significant part of the engine’s power output is derived not just from the fact that it is turbocharged with variable cam timing but also because it has gasoline direct injection (GDI). The high-pressure fuel injector is placed strategically inside the combustion chamber, which sprays the fuel directly onto the top of the piston. As the spark plug fires, the gasoline burns more efficiently, providing a cleaner burn, producing more power, less emissions, and greater fuel efficiency. A high-pressure fuel pump at the back left of the engine bay supplies fuel to each injector. (Ford’s 2.0L Ecoboost was the first naturally aspirated engine with GDI technology, appearing in the ‘12 Ford Focus in 2011).

The turbocharger is twin-scrolled (which was a favorite modification for many four-cylinder engines in 2015). Car companies like Hyundai, Kia, BMW, and Audi successfully used it, and Ford applied the technology to their four-cylinder to help produce power numbers to compete.

The Performance Of The 2.3 L Ecoboost Engine

The 2015 Mustang is the best-known use of the 2.3L Ecoboost engine. It produced 310 hp and 320 lb-ft of torque, and when tested by Motor Trend in the fall of 2014, the new Mustang exceeded expectations, producing a 5.6 second 0 - 60 mph time and 14.1 second quarter mile time @ 98 mph. While MotorTrend quickly pointed out that the new four-cylinder would not replace the powerful V8, it was a much-improved engine over the anemic V6s that Ford had been churning out.

Ford trumpeted its new engine to the public, proclaiming best-in-class fuel economy and the numbers seemed to bear out their excitement. The 2.3L Ecoboost produced 32 mpg on the highway, which seemed too good to be true to young Mustang owners who wanted speed but didn’t want to waste their money at the gas pumps every week. The engine was paired with a six-speed manual or six-speed Selectshift automatic transmission.

The Production Numbers For The 2.3L Ecoboost Engine

Regarding Mustang sales, the redesigned pony car has been well-received. In 2015, Ford posted significant gains in Mustang sales, selling over 110k Coupes (along with 30k Convertibles) that year alone. While Ford anticipated that the smaller four-cylinder would open up international markets in a way they had never encountered, most global sales were V8s. At the same time, the Ecoboost engine accounted for most of its domestic sales. The demand for the Ecoboost in Europe was so small that Ford dropped the engine, preferring to promote the eight-cylinder engine in 2021.

While the Mach-e Mustang has undoubtedly eaten into the 2.3L Ecoboosts sales, Ford continues to offer the Mustang and is one of the last car companies to offer an internal combustion engine sports car. Many other companies have announced plans to switch to electric motors for high-performance vehicles.

The Issues With The 2.3L EcoBoost Engine

While the 2.3 L has enjoyed great success over the years, several issues have been reported with the motor.

Carbon Build Up

Most direct-injected motors suffer from excessive carbon buildup, and the Ecoboost is no exception. Since no fuel flows over the intake valves as with regular port fuel injection engines, the valves retain carbon deposits from the explosion inside the combustion chamber. While many gasolines have cleaning agents and additives, these chemicals are not enough to keep the build-up of burnt fuel and air from happening. As the carbon builds up, the airflow tends to become more restrictive, which can lead to a loss of power and fuel economy.

While there are carbon cleaning services (which are probably needed if you are encountering symptoms), owners can keep the issue to a minimum with regular maintenance. Be sure to get oil changes down routinely and use the correct fuel for your vehicle.

Leaking Head Gaskets

Early versions of the 2.3 Ecoboost engine had head gaskets that tended to seep. While this is not a problem for more recent engine iterations, Ford did find it happening on early Focus RS and some Mustang engines. While the 2.3L is a relatively new engine, and many early motors are just now approaching 100k miles, the issue is worth watching. A leaking gasket can continue to seep until it becomes a full-blown leak, causing the oil to burn away on other hot engine components. It is a relatively easy repair if you suspect a gasket leak.

The Specs Of The 2.3L Ecoboost Engine