Understanding API and ACEA Oil Standards: A Simple Guide

Choosing the right engine oil is easier when you understand the API (American Petroleum Institute) and ACEA (European Automobile Manufacturers’ Association) standards. These guidelines help you pick the best oil for your vehicle, whether it’s a gasoline or diesel engine or needs special pollution control systems. 

The API standard focuses on oil’s ability to clean and protect the engine, while the ACEA standard helps match the oil to your car’s specific needs. Knowing these standards ensures your engine runs smoothly and lasts longer.

What is the ACEA Oil Standard?

The ACEA oil standard is a set of rules made by the European Automobile Manufacturers’ Association. It helps people know how suitable engine oil is for different types of vehicles.

Each oil type has a letter and number, like A1.

• The letter tells you what kind of engine the oil is for:
  • A = for gasoline (petrol) engines
  • B = for diesel engines in regular cars
  • C = for small engines that have special parts like catalytic converters or filters
  • E = for big trucks and commercial vehicles

The number shows how well the oil performs. A higher number means the oil works better.

In the 2016 ACEA guidelines, oils are grouped like this:

• For gasoline and diesel car engines:
  • A3/B3, A3/B4, A5/B5
• For engines with pollution control systems:
  • C1, C2, C3, C4, C5
• For trucks and commercial vehicles:
  • E4, E6, E7, E9
  • E6 and E9 are for vehicles that help reduce pollution.

What is the SAE Oil Standard?

The SAE oil standard was made by a group called the Society of Automotive Engineers. It tells us how thick or thin the oil is, which is called viscosity.

You’ll see numbers like this on the oil bottle: 00W00

• The first number (before the “W”) shows how well the oil works in cold weather.
  • A lower number means the oil flows better when it’s cold, which helps your engine start more easily.
• The second number (after the “W”) tells how the oil works when it’s hot.
  • A higher number means the oil protects the engine better when it gets really hot.

So, this rating helps you choose the right oil for both cold starts and hot engine temperatures!

What is the API Oil Standard?

The American Petroleum Institute made the API oil standard. It helps people know how good the oil is at:

• Cleaning the engine
• Protecting it from damage, rust, and wear

This standard uses two letters to show what kind of engine the oil is for and how well it performs:

• The first letter tells you the type of engine:
  • S = for gasoline (petrol) engines
  • C = for diesel engines
• The second letter shows how good the oil is.
  • The later the letter in the alphabet, the better the oil.
  • For example, SH oil is not as good as SN oil.

To find out which oil is right for your vehicle, check your car’s owner’s manual. You can also use tools or check out our Fubex Lubricants engine oil catalog to find high-quality oils for your engine.

ACEA A/B Oils: For Gasoline and Light Diesel Engines

ACEA A/B oils are strong and reliable engine oils. They are made for gasoline engines and small diesel engines (like in cars and vans). These oils work well in high-performance engines, meaning engines that need extra care and protection.

Here’s a simple guide to the different types:

• A1/B1 – These oils are thin and smooth, which helps the engine use less fuel and work better at high temperatures.
• A3/B3 – These are used for long drives and in tough conditions.
• A3/B4 – Great for powerful diesel engines that use direct injection. These can also replace A3/B3 oils.
• A5/B5 – Just like A1/B1, these are low-friction oils that help the engine run easily and save fuel.
• A7/B7 – These oils protect modern engines, especially those with turbochargers. They help stop engine problems like early ignition, wear and tear, and dirt buildup in turbo parts.

ACEA C-Grade Oils: Low-SAPS and Mid-SAPS Oils

Some engine oils have extra chemicals like phosphorus and sulfur. These help protect the engine by reducing wear, friction, and rust. But, too many of these chemicals can damage parts in the exhaust system, like the diesel filter or catalytic converter.

That’s why the ACEA (European Automobile Manufacturers’ Association) made rules to limit how much of these chemicals can be in engine oils.

Engine oils with less phosphorus and sulfur are called low-SAPS oils. “SAPS” stands for sulfated ash, phosphorus, and sulfur. These oils belong to the C group in ACEA’s oil guide. The “C” means the oil is safe for engines with special filters.

C-grade oils are:

• Smooth and low-friction
• Thin (low viscosity)
• Good for engines with diesel filters (DPF) or catalytic converters (TWC)
• Used in modern gasoline and diesel engines

C-grade oils come in two types:

• Low-SAPS (C1 and C4): Very low ash content, good for sensitive filters
• Mid-SAPS (C2, C3, C5, C6): Slightly higher ash, still good for most filters

Breakdown of C-Grade Oils:

C1 – Low-SAPS Oil

• Thin and low-friction
• Very low in sulfated ash (less than 0.5%)
• Great for engines that need low-ash oil

C2 – Mid-SAPS Oil

• Low-friction and fuel-saving
• Sulfated ash content is less than 0.8%
• Good for engines needing mid-SAPS oil

Important: You can’t use just any C-grade oil in your car. Always check your car’s manual to find the right one!

C3 – Mid-SAPS Oil

• Has less than 0.8% ash
• It’s a low-friction oil, which means it helps the engine run smoothly.
• Good for cars that need a thicker oil when hot (HT/HS viscosity is at least 3.5)

C4 – Low-SAPS Oil

• Similar to C1 oils
• Also stays strong and thick when hot (HT/HS viscosity is at least 3.5)
• Doesn’t have a lower limit for phosphorus, so it’s safer for filters.

C5 – Mid-SAPS Oil

• Similar to C2 and C3 oils
• The main difference: it’s a bit thinner when hot, with a viscosity between 2.6 and 2.9
• Helps the engine save fuel and reduce friction

C6 – Mid-SAPS Oil

• A stable oil with a viscosity of at least 2.6
• Helps protect the engine from early ignition problems
• Great for turbocharged gasoline engines and modern diesel engines
• Keeps the engine clean and helps stop the damage from heat and dirt

ACEA E-Grade Oils: For Big Trucks and Heavy-Duty Engines

E-grade oils are made for big vehicles like trucks, buses, and heavy machines. These oils are strong and can handle tough driving conditions. There are different types based on what the engine needs:

E2 – Old Oil Type

• It was used in normal and turbo diesel engines.
• Worked well for medium to heavy-duty jobs
• Stopped being used in 2010

E4 – Long-Lasting Oil

• Great for synthetic engines
• It can go a long time before needing a change.
• Meets Euro 3, Euro 4, and Euro 5 emission rules (these rules help keep the air clean)

E6 – For Clean-Running Engines

• Works with Euro 4, 5, and 6 engines
• Safe to use with special filters and systems that reduce pollution (like DPFs and SCR systems)

E7 – Heavy-Duty Oil

• Works in tough jobs and heavy-duty trucks
• Good for Euro 3, 4, and 5 engines
• It can also last longer before changing.

E9 – Modern Diesel Engine Oil

• Made for newer diesel engines
• Works for engines with or without a diesel filter
• Meets Euro 4, 5, and 6 emission standards

E11 – Super Strong Oil

• Replaces E9 oils
• A mid-SAPS oil that protects filters and keeps engines clean
• Great for diesel engines with filters
• Has a lower viscosity (less than 3.5), so it flows easily but still protects

Tip: Always use the oil your truck or machine needs. Using the wrong one can damage your engine or break the filters.

The SAE Oil Standard

The SAE (Society of Automotive Engineers) sets rules to measure how thick or thin oil is. This is called viscosity.

You’ll see something like this on the oil bottle: 00w00.

• The first number (on the left) shows how the oil works when it’s cold. The lower the number, the better it works in cold weather.
• The second number (on the right) shows how the oil works when it’s hot. The higher the number, the better the oil works when the engine gets hot.

The API Oil Standard

The API (American Petroleum Institute) has its way of measuring oil. It looks at how well the oil cleans the engine and protects it from wear, rust, and dirt.

The API uses two letters:

• S is for oil that goes in gasoline engines (like cars that run on regular gas).
• C is for oil that goes in diesel engines (like trucks and bigger vehicles).

The second letter tells you how good the oil is. The further down the alphabet, the letter is, the better the oil. For example, SN oil is better than SH oil.

The Importance of Lubricants in Heavy-Duty Vehicles

Heavy-duty vehicles are super important for the global economy because they help move goods everywhere. However, they can also hurt the environment because of greenhouse gas emissions. 

That’s where lubricants come in. These special oils help reduce harmful emissions and keep vehicles running smoothly. For fleet operators, using the right lubricants is key to making vehicles more productive and keeping costs down.

Final Thoughts: Understanding API and ACEA Oil Standards

Understanding API and ACEA oil standards helps you choose the best oil for your vehicle, whether it’s gasoline or diesel, and if it has special filters. API oils focus on cleaning and protecting, while ACEA oils match your engine’s needs. 

By considering viscosity and the engine’s requirements, you can ensure smooth performance and long-lasting protection. Always check your vehicle’s manual to pick the right oil for optimal care.

FAQs

Q1: What does API mean in oil?

API stands for the American Petroleum Institute. It sets standards for engine oils in gasoline and diesel engines to ensure they meet the quality needed for modern engine technology.

Q2: What are the three types of engine oil?

The three main types of engine oil are synthetic, semi-synthetic, and conventional oil. Each type serves the same purpose but offers different levels of performance and protection.