Mercedes A-Class at the gas station

What Fuel Does the Mercedes A-Class Need? (95 vs. 98 RON)

One question we often get from Mercedes A-Class owners is, “What type of fuel should I put in my car?”

So, let’s answer it!

The Mercedes A-Class will run fine on E10 petrol (95 RON). However, for the A35 AMG and A45 S AMG models, super unleaded (98 RON) is recommended for optimal performance.

By the end of this article, you’ll clearly understand why these recommendations exist.

So, let’s start!

At a Glance: What fuel grade does the Mercedes A-Class need?

Before diving into the details of octane levels, let’s get straight to the answer many of you might be looking for.

After all, sometimes, all we want is a straightforward response, right?

  • For a regular Mercedes A-Class: A regular Mercedes A-Class like the A180 or A200 will run safely on regular E10 petrol. However, premium unleaded (95 RON) fuel may help prolong the engine’s lifespan.
  • For Mercedes-AMG models: Super unleaded (98 RON) fuel is recommended for the A35 AMG and A45 S AMG models.
  • Tuned Mercedes A-Class: If you’ve given your A-Class an ECU tune (for example, using a RaceChip), fill it up using super unleaded (98 RON) fuel.

Quick note: Occasionally using E10 fuel in your A-Class won’t necessarily damage it. But if you want the best for your vehicle long-term, sticking to the recommendations is the way to go.

Stick around if you’d like a deeper dive into why these recommendations exist. Otherwise, happy driving!

Does the Mercedes A-Class require 95 or 98 RON?

Time to dive a little deeper!

According to the Mercedes A-Class owner’s manual, the vehicle is suitable to use with E10 fuel (95 RON):

Mercedes A-Class owner's manual recommended fuel grade

Tip: The correct gas type for your Mercedes A-Class will always be written on the inside of the fuel filler cap.

However, if you own an AMG version of the A-Class, like the A35 or A45 S, it’s recommended to use super unleaded (98 RON) for optimal performance.

While an occasional tank of E10 isn’t the end of the world, consistently using this fuel grade can lead to issues like engine knocking, reduced power, and even potential long-term engine damage.

Mercedes-AMG A45 S engine

And what about a tuned Mercedes A-Class?

Modifications like RaceChip can significantly increase the power of your Mercedes-Benz A-Class. But when you upgrade the engine’s performance, its gas needs an upgrade too.

Just as an athlete on a rigorous training regime needs specialized nutrition, a tuned A-Class requires premium or super unleaded fuel (98 RON).

Difference between standard, premium, and super unleaded

Fueling up might be a mundane task, but there’s a science to it.

Behind each pump, there’s a lot of chemistry going on to make our vehicles run smoothly.

So, if you’ve been wondering, “What do these fuel grades mean?” let’s take a look!

The octane (RON) rating of a gasoline type indicates its resistance to premature detonation or knocking.

In car terms, knocking is a rattling or pinging sound you’d hear when the air-fuel mixture in the cylinders detonates earlier than it should. It’s not good for your engine!

The higher the octane rating, the more compression the gas can withstand before it ignites, which reduces the likelihood of knocking and leads to smoother engine performance.

When you’re filling up, you will typically see the following fuel grades:

  • Standard unleaded (E10, 95 RON): This is the most common fuel type found at petrol stations. The ‘E10’ indicates it contains up to 10% ethanol, making it more environmentally friendly. Its 95 Research Octane Number (RON) rating means it is suitable for everyday driving in standard vehicles.
  • Premium unleaded (E0/E5, 95 RON): This fuel also has a 95 RON rating but is distinguished by its ethanol content. ‘E0’ indicates no ethanol, while ‘E5’ contains up to 5% ethanol. Given its potentially lower ethanol content compared to E10, it might be preferred by older vehicles or those with engines sensitive to ethanol.
  • Super unleaded (98 RON): With a 98 RON rating, this fuel is designed for high-performance engines, ensuring efficient combustion and resistance to knocking. This petrol is ideal for high-performance vehicles, sports cars, and luxury cars.
Fuel grades choices at petrol station

Can you use ethanol-based fuels for the Mercedes A-Class?

Ethanol-based fuels are fuels that contain ethanol, which is a renewable fuel made from biomass. Biomass consists of a variety of plant materials.

It looks something like this:

Corn put into the gas tank filler cap of a car

That’s a joke, of course!

In reality, most petrol sold in the UK and Europe contains (renewable) ethanol. The most common ethanol-based fuel is E10, which consists of up to 10% ethanol.

Ethanol-based fuels reduce air pollution, but at the same time, using gas that contains a high concentration of ethanol can damage your vehicle.

E10 is a standard that’s commonly accepted to be safe for most cars on the road today, including the Mercedes A-Class.

Once you increase the ethanol percentage further, it won’t be too good for your car.

For instance, E85 gas is also available in some places, but it can only be used for your Mercedes A-Class if you have a flex-fuel kit.

FAQs about fuel for the Mercedes A-Class

If you have any more questions about which fuel to use for your A-Class, take a look at these FAQs:

What if I accidentally put standard fuel in my Mercedes A-Class?

Filling your Mercedes A-Class with regular fuel won’t cause any harm. However, you might notice reduced performance and engine knocking. To prevent potential issues, it’s a good idea to top off with premium fuel on your next fill-ups.

Can I use fuel additives for the Mercedes A-Class?

You can use fuel additives or cleaners for the Mercedes A-Class. However, it is important to carefully read the manual beforehand and avoid using additives more than twice a year, as this can damage the engine or fuel system.

Can the Mercedes A-Class take 99 or 102 RON fuel?

Filling up a Mercedes A-Class with 99 or 102 RON fuel will allow it to extract its maximum performance and engine longevity. However, 98 RON fuel is just as good unless you have an AMG model.

Final verdict

To summarize: You can safely use standard E10 fuel in your Mercedes A-Class.

Let us know what you thought of this article, and if you have any more questions, drop a comment below!

Gas requirements for other Mercedes models

Are you interested in the required gas type of other Mercedes-Benz models?

If so, you can find everything you need to know in the following articles:

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