Audi A4 Sedan white with visible fuel filler cap

What Gas Does an Audi A4 Use? (Can It Use Regular Gas?)

If you’re the proud owner of an Audi A4, one question might be on your mind: “What kind of gas should I fill it up with?”

Can the Audi A4 use regular gasoline, or does it need premium?

The Audi A4 can use regular (87 octane), mid-grade (89 octane), or premium (91/93 octane) gas. The Audi A4 can safely run on regular gas, but Audi recommends using premium gas for increased resistance against knocking.

Read on for more information about the fuel type for your Audi A4!

At a Glance: What gas can be used for your Audi A4?

Alright, let’s get straight to the point.

You’re here because you want to know what gas to use for your Audi A4 without diving into all the technical jargon. Gotcha!

  • For the standard Audi A4: If your car is the base model with the 2.0-liter TFSI turbo engine, it’ll drive just fine with regular (87 octane) gas. However, the experts (and your car’s manual) recommend using premium (91 octane) gas. Why? We’ll discuss it in a bit, but in a nutshell, it’s all about taking care of your engine.
  • For the high-performance Audi models: Driving an Audi S4 or the beastly RS4? First off, nice choice! It’s a clear call for these: fill them up with premium (91 octane) gas. Sure, they can tolerate regular gas occasionally, but for that thrilling performance you bought it for, premium gas is the way to go.
  • Tuned Audi A4: If you’ve given your (base) Audi A4 a tune (for example, using a RaceChip), then be sure to use premium (at least 91 octane) fuel.

If you prefer a table overview, here is what you should know:

CategoryTypeIs It OK?Notes
GasRegular (87 octane)Minimum required octane level by Audi, the car will run safely.
GasMid-grade (89 octane)
GasPremium (91 octane)Recommended octane level by Audi, the engine will be more resistant to knocking.
GasPremium (93 octane)
GasEthanol-based (E10)Same as the typical gas at most pumps.
GasEthanol-based (E15)!Not optimal for the car, but it won’t be a danger in the short term. It can only be used for Audi A4s from 2001 or newer.
GasEthanol-based (E85)!Mostly not OK. It can only be used if your A4 has a flex-fuel system.
GasReformulated Gasoline (RFG)A type of gas that burns more cleanly, about 30% of the gas sold in the US is RFG. (Source)
AdditivesFuel injector cleaner!Be careful; it can potentially damage the engine when overused.
AdditivesOctane booster!Be careful; it can damage the engine when misused.
AdditivesFuel stabilizer!Be careful; it can damage the engine when misused.

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

Does an Audi A4 require regular or premium gas?

Time to delve a little deeper!

Per the owner’s manual of an Audi A4, regular gas (87 octane) is the minimum required fuel type, but premium gas (91 octane) is recommended:

Audi A4 owner's manual: gas type

In simple terms, if you fill up your Audi A4 with regular (87 octane) gas, it will run safely. Any lower-octane fuel (lower than 87), and you risk damaging the fuel system or engine.

Tip: The correct gas type for your Audi A4 will always be written on the inside of the fuel filler cap.

But here’s the thing – just because someone can survive on fast food doesn’t mean it’s the best choice for their health.

Similarly, your A4’s engine is designed to reach its full potential with premium (91 octane) gas. Audi’s engineers and the manual agree that premium gas will positively impact your fuel economy, engine performance, and long-term maintenance costs.

Audi A4 sedan in district metallic green

If you have a performance-oriented version of the Audi A4, like an S4 or even an RS4, the gas recommendation is more stringent. These high-performance models thrive on premium (91 octane) gas.

Can you fill up an S4 or RS4 with regular gas? Technically, yes.

If the only available option is 87 octane, it won’t instantly harm your car. However, consistently using regular gas is like making an athlete continuously run in ill-fitting shoes. They might manage, but it’s not ideal.

Learn more: Audi A4: 6 Engine Problems Reported By Owners In 2024

And what about tuned Audi A4s?

Modifications like RaceChip can increase the horsepower of your Audi A4. And when you upgrade the engine’s performance, its diet needs an upgrade too.

Just as an athlete on a rigorous training regime needs specialized nutrition, a tuned A4 needs the high-octane boost of premium (91-octane) gas.

Ultimately, using regular gas, especially in the performance models or tuned versions, might initially save you a few bucks at the pump.

But in the long run, it can affect your car’s performance, fuel efficiency, and even its lifespan.

Reduced acceleration, less-than-smooth rides, and more visits to the mechanic? We’d rather avoid that, wouldn’t we?

Difference between regular, mid-grade, and premium gas

Now that we’ve discussed the recommended gas type for your Audi A4, you might wonder, “What do these octane numbers mean?”.

Octane ratings are a measure of the fuel’s resistance to knocking.

No, it’s not like door-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 gas types:

  • Regular gas (87 Octane): This is the basic option. It’s the most common and budget-friendly. It’s suitable for many vehicles but not necessarily an excellent choice for high-performance cars.
  • Mid-grade gas (around 89 Octane): Slightly pricier than regular, it’s often seen as a compromise between cost and performance. Perfect for those who want higher-quality fuel without splurging too much.
  • Premium gas (91 Octane and above): Designed for high-performance engines, this gas resists knocking, ensuring smoother combustion. If cars could dream, many would probably dream of this.

The main difference between regular, mid-grade, and premium gas is that regular gas has an octane rating of 87, mid-grade gas has an octane rating of 89, while premium gas has an octane rating of 91 or higher.

Regular (87 octane), mid-grade (89 octane), and premium (93 octane) gas at a pump

Here’s something more to think about: premium gas offers benefits that go beyond preventing knocking. It ensures optimal performance, fuel efficiency, and longevity for cars, especially those designed to be high-performers.

High-end cars (like Audi models) often have advanced engines optimized for higher compression ratios. These engines thrive on the richness of premium gas, which in turn offers better acceleration, fuel economy, and longevity.

Real-world experiences with Audi A4 gas choices

Not convinced by the benefits of premium gas? Let’s check out some real-world experiences from Audi A4 owners!

1. Experimenting with regular gas

One Audi enthusiast from Central Florida shares:

Here in Central Florida regular gas costs 20-24% less than premium gas and since premium is recommended but not required by Audi, I decided to try an experiment to see what the impact would be on fuel economy by switching to regular (87 octane) fuel for a little while.

After 4 full tanks of regular fuel my long term fuel economy went from 29.2 to 29.7 mpg and my average speed went from 37 to 38 mph. I was expecting the long term fuel economy to drop slightly so I was rather surprised that it actually went up.

Acceleration seemed to be very slightly slower with the regular gas as opposed to my normal 93 octane fuel.

I calculated it would save me about $500/yr in gas cost using regular.


2. Premium vs. regular gas

Another Audi owner crunches the numbers:

So I drive a little more than 12k miles per year and since I bought the car I have gotten an average of 30.5 mpg so I use about 400 gallons of gas per year. At a price difference of $0.25 per gallon the cost difference between burning regular and premium is $100/year. After doing the math it really is not worth worrying about the $100/yr so I will probably just keep burning premium (even though I lease the car).


3. Mileage drops with lower octane

A fuel-conscious A4 owner notes:

You will end up paying more to run the car on regular or midgrade (assuming it’s less than 91 or so) than you do to run the car on premium. The cost difference between premium and regular is what, 2-4 dollars per tank? Let me put it this way, our b6 on premium gets about 20-21 in the city, and 32ish on the highway. However, with midgrade it gets about 16 in the city, and 24 on the highway.


Can you use ethanol-based fuels for the Audi A4?

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, over 98% of gasoline in the US contains ethanol. The most common ethanol-based fuel is E10, which consists of 10% ethanol and 90% gasoline.

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 Audi A4.

However, you may occasionally find E15 gas containing 15% ethanol and 85% gasoline. In the US, E15 can be found in 30 states at over 2,400 pumps (source).

E15 is not optimal for the Audi A4, but it won’t be a danger in the short term. However, it can only be used for Audi A4s from 2001 or newer.

Once you increase the ethanol percentage further, it really 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 Audi A4 if you have a flex-fuel kit.

FAQs about gas for the Audi A4

If you have any more questions about which gas to use for your Audi A4, take a look at these FAQs:

What happens if I accidentally fill up with regular gas in my Audi A4?

Nothing will happen if you put regular gas in your Audi A4. The Audi A4 is designed to run safely on regular gas. However, if you can, it is advisable to use premium gas.

Can I use fuel additives for the Audi A4?

You can use fuel additives or cleaners for the Audi A4. 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 you use reformulated gasoline (RFG) for Audis?

You can use reformulated gasoline (RFG) for your Audi as it won’t cause any damage to your car, including the fuel system or the engine.

Final verdict

So, can an Audi A4 use regular gas?

In short, yes, but it is not recommended.

Premium gas, as per Audi’s recommendation, ensures optimal performance and longevity for your A4. You invested in a luxury car, so it’s only fitting to give it the best to ensure it runs at its peak.

From a purely economic standpoint, while regular gas offers initial savings at the pump, the potential longer-term costs, reduced fuel efficiency, and potential wear and tear could nullify those savings.

Now that you know what gas to use for your Audi A4, enjoy the drive!

If you have any more questions, feel free to contact us. We’re always happy to help!

Reader’s tip: If you’re an Audi A4 owner, check out this article: 7 Tips For Your Audi A4 (Features You Never Knew Existed)

Gas Requirements For Other Audi Models

Are you interested in the required gas type of other Audi models?

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

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