Mercruiser 4.3 Oil Type & Capacity [November 2022]

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Mercruiser 4.3L was first introduced in 1991 by Mercury Marine. It is a series of V8 two-stroke engines used in trimarans, tenders, inflatables and personal watercraft. I’ve included below all you need to know about oil type and capacity.

Did you know that there are several different classes of Mercruiser 4.3L engines? It’s true, and if you own a Mercruiser 4.3L engine it’s important that you know what type of oil to use.

Mercruiser 4.3L engines are some of the most popular engines on the market today. It’s no wonder either, as they have withstood the tests of time and continue to provide reliable power for years to come — its 30+ year old motor has been used in automotive competitions across the country.

Read More about – Mercruiser 3.0 Oil Type & Capacity

Whether you plan on using your Mercruiser 4.3L engine for racing or just want a reliable power source for your favorite fishing boat, you need to learn everything you can about this powerful engine. The engine type, oil type and oil capacity will help you better understand what makes your Mercruiser 4.3L special and how to prepare it for use.

Mercruiser 4.3L Oil Capacity

The Mercruiser 4.3L oil capacity is 4.5 US Quart. Detail for different serial range are as follows.

Ser. # Range: 0A331455 – 08773242

Ser. # Range: 0F803800 – 0K999999

Oil Capacity: 4-1/2 US qt (4.3 L)

Ser. # Range: 08773243 – 0M299999

Oil Capacity: 4-1/2 US qt (4.3 L)


Ser. # Range: OL012009 – 0M299999

Oil Capacity: 4-1/2 US qt (4.3 L)


Ser. # Range: 0M300000 and up

Oil Capacity: 4 US qt (3.8 L)

MCM 4.3L & MPI

The manufacturer recommends using synthetic blend 20W-40 or 25W-40 for Mercruiser 4.3 engine.

The 4.3L Mercruiser engine is a marine engine made by Mercruiser (a division of Johnson Mercruiser Inc). The first use of the 4.3L was in 1989 for the 1990 year model boat. This is a V6 3-bank configuration motor – three cylinders, each with its own combustion cylinder head. It is a true marine engine that has a separate block from the crankshaft and crankcase area. Because of this unique design it requires specific lubrication methods to help protect it from corrosion, cavitation and wear. These important features benefit both you the owner, and your mechanic or service person servicing the 4.3L engines.

As we all know, lubrication is one of the most important elements to engine longevity. You take pride in your boat and don’t want to compromise the performance of your boat, so it’s vital that you choose the best Mercruiser 4.3L oil type for your engine.

So without further ado, lets list some of the best marine engine oils you can use for the best performance of your Mercruiser 4.3L engine.

1. Quicksilver 25W-40 Synthetic Marine Engine Oil

If you own a 1997 – 2004 Mercruiser 4.3L engine, you should use a high-quality synthetic engine oil like Quicksilver 25W-40 Synthetic Marine Engine Oil.

Why? Here are three reasons that make it the best engine oil for your boat’s Mercruiser 4.3L:

There’s a reason why Quicksilver is the most recommended marine engine oil by Mercruiser, Yamaha, and Volvo Penta.

It outperforms automotive oils in marine applications because of its specialized additive package designed for marine engines. Over 5 years of engineering and development by the largest marine engine manufacture in the world

-For use in all 4-Stroke marine engines – New formula 4-Stroke oils are engineering approved for all marine 4-Stroke applications, including: Outboard, Mercruiser, High Performance, Stern Drive/Inboard, and exceeds all marine industry 4-Stroke oil requirements including FC-W and FC-W Catalyst Compatible.

-Flagship engine and corrosion protection – Industry leading strength and viscocity retention and ultimate corrosion and wear protection .

You can trust that Quicksilver will protect your engine and keep it running at its optimal performance level.

2. MERCURY Genuine 1 Gallon 4-Cycle Oil

Mercury Genuine Engine Oil for Mercruiser 4.3L is a high-quality, long-lasting oil that provides excellent protection for your engine, as well as all components of your boat. It’s designed to withsand extreme temperatures and pressures, so you can be sure it will do its job no matter what conditions you’re working in.

The engine oil is formulated to keep your engine running smoothly and efficiently while also reducing the risk of corrosion and wear on critical parts like pistons and bearings.

Mercury Genuine Engine Oil for Mercruiser 4.3L is available in different oil weights, so you can find one that fits your needs perfectly.

Mercury 4.3L Genuine Engine Oil is a high-performance synthetic oil that is recommended for use in Mercury’s four-stroke engines. It is specially formulated to provide the protection needed to keep your engine running smoothly and reliably. Mercury 4.3L Genuine Engine Oil has an API service classification of CJ-4, SJ, and SH, which means that it will work well in multiple types of engines and conditions.

Mercury Genuine engine oil is designed to help preserve the quality of your engine while meeting the demands of your specific boat. It’s formulated with a blend of synthetic and conventional oils, which enhances performance in all weather conditions and extends engine life by up to 10%.

Mercury, the name you can trust. Mercury is a brand of powerboat engines that has been trusted by boaters since 1939. The Mercury brand has been a leader in innovation and design, and they continue to push the boundaries of what’s possible when it comes to engine performance and horsepower.

One of the most important parts of any engine is its lubricating oil, and Mercury understands this better than anyone else. They only use the highest quality synthetic oils that are specifically designed for their engines.

The Mercury brand has always been about pushing limits and going beyond expectations, but with their line of motor oils you can rest assured knowing that your Mercruiser 4.3L engine’s performance will be at its best no matter what kind of weather conditions you’re dealing with!

How to Change Oil on Mercruiser 4.3L Engine Boat

Quick video explaining how to do an oil change on 4.3 Mercruiser Boat using Quicksilver SAE 25W-40 engine oil.

The video below shows in depth on oil change and tune up on Mercruiser 4.3L boat

As you already know proper and regular maintenance ensures smooth running of engine and its parts and if you need help with Mercruiser 4.3L engine boat maintenance. Here is the video walkthrough for you.


What kind of oil does a MerCruiser 4.3L take?

The recommended oil for Mercruiser 4.3L is Full-Synthetic Engine Oil, 20W-40 by Mercury Marine.

How much oil does a Mercruiser 4.3L hold?

The Mercruiser 4.3L holds around 4 to 4.5 quartz of oil.

What is 20W-40 in engine oil?

In engine oils 20W-40 is an SAE grade where 20 is weight/viscosity of oil on colder temperatures or in winter and 40 is weight and oil viscosity of oil at high temperature.


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