BMW X5: Regular or Premium Gas? Find Out What’s Best!

If you’ve clicked on this article, you’re likely a BMW X5 owner.

And one question we often get is, “What type of gas should I use?”

So, let’s answer it!

The minimum gas type for the BMW X5 is mid-grade gas (89 octane), although premium gas (91 octane) is recommended. Regular gas (87 octane) should be avoided as you risk damaging the engine.

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

So, let’s start!

At a Glance: What gas Type does your BMW X5 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 BMW X5: A regular BMW X5 like the xDrive35i or xDrive40i requires mid-grade gas (89 octane) at minimum. However, the experts and your BMW owner’s manual recommend using premium gas (91 octane).
• For M-performance models: Do you own a BMW X5 M50i, M60i, or even a BMW X5 M? If so, they all require premium gas of at least 91 octane, although BMW recommends 93 octane gas for optimal performance.
• Tuned BMW X5: If you’ve given your BMW X5 an ECU tune (for example, using a RaceChip), fill it up using premium gas (at least 91 octane).

Quick note: Occasionally filling up with regular (87 octane) or mid-grade gas (89 octane) won’t necessarily damage your car. But if you want the best for your vehicle long-term, sticking to the recommendations is the way to go.

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

Category	Type	Is It OK?	Notes
Gas	Regular (87 octane)	!	Not recommended.
Gas	Mid-grade (89 octane)	✓	Minimum octane rating recommended by BMW, the car will run safely.
Gas	Premium (91 octane)	✓	Recommended octane rating by BMW, which can prevent knocking sounds and prolong the engine life.
Gas	Premium (93 octane)	✓
Gas	Ethanol-based (E10)	✓	Same as the typical gas at most pumps.
Gas	Ethanol-based (E15)	!	Not optimal for the car, but it won’t be a danger in the short term. It can only be used on BMW X5s from 2006 or newer.
Gas	Ethanol-based (E85)	!	Mostly not OK. It can only be used if your BMW X5 has a flex-fuel system.
Gas	Reformulated Gasoline (RFG)	✓	A type of gas that burns more cleanly, about 30% of the gas sold in the US is RFG. (Source)
Additives	Fuel injector cleaner	!	Be careful; it can potentially damage the engine when overused.
Additives	Octane booster	!	Be careful; it can damage the engine when misused.
Additives	Fuel 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 BMW well!

Reader’s tip: A 2024 Study On BMW’s Reliability: Are They Good Cars?

Does a BMW X5 require regular or premium gas?

Time to dive a little deeper!

According to the owner’s manual of a BMW X5, mid-grade gas (89 octane) is the minimum fuel type, but premium gas (91 octane or higher) is recommended:

So, if you fill up your BMW X5 with mid-grade gas (89 octane), it will run safely. However, you risk damaging the fuel system or engine by using regular gas (87 octane).

Tip: The correct gas type for your BMW X5 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, the engine of your BMW X5 is designed to reach its rated performance and consumption values with premium gas (91 octane). It can also positively impact how long your X5 will last!

If you own an M-performance version of the BMW X5, like the X5 M50i, M60i, or X5 M, premium gas (91 octane or higher) is a must.

While an occasional tank of regular (87 octane) or mid-grade gas (89 octane) isn’t the end of the world, consistently using this gas type can lead to issues like engine knocking, reduced power, and even potential long-term engine damage.

And what about a tuned BMW X5?

Modifications like RaceChip can significantly increase the power of your BMW X5. 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 BMW X5 requires premium gas (91 octane or higher).

Difference between regular, mid-grade, and premium gas

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 octane numbers mean?” let’s take a look!

The octane 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 gas types:

• Regular gas (87 octane): Regular gas is the most common and least expensive type of gasoline available at most stations. It’s best for everyday vehicles that don’t demand high performance.
• Mid-grade gas (around 89 octane): As the name suggests, mid-grade gas sits between regular and premium gasoline in terms of performance and price. Perfect for those who want higher-quality fuel without paying too much.
• Premium gas (91 octane and above): Designed for high-performance engines, this gas resists knocking and ensures smoother combustion. It’s best for high-performance vehicles, luxury cars, and those with turbocharged engines.

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.

High-end cars (like BMW models) often have advanced engines that run on relatively high compression ratios. These engines thrive on the richness of premium gas, offering better acceleration, fuel economy, and longevity.

Real-world experiences with BMW X5 gas choices

Not convinced by the benefits of premium gas? Let’s check out some real-world experiences from BMW X5 owners!

1. Horror stories of using regular gas

A manager from a BMW dealership highly suggests not using regular or mid-grade gas:

I highly suggest not using 87 or 89 octane. For those who say they use it and have not had any problems, be prepared for some down the line. I work at a BMW dealership as a Warraty Manager, there are some horror stories when a customer uses 87 or 89 octane. Save a couple cents here and there but you’ll utlimately pay the price.

Source

2. Experimenting with gas types

Here’s an X5 owner who experimented with Chevron 94 and Shell 91 gas types:

Mine says Minimum 89 but in Canada, I tried a little experiment, I put in a maybe a bar Chevron 94, drove it around and it felt normal, put Shells 91 and I drove it around for a bit, it felt sluggish and completely different. That’s just me tho, the proper way is to probably dyno it.

Source

3. Testing the fuel economy

Lastly, here’s someone who found no difference in MPG when switching from 91-octane to 93-octane gas:

My trips north start with a ~90 mile run through the boonies where there is no traffic (variable that greatly affects fuel economy). I’ve done that leg with 91 AKI and 93 AKI gasoline, and there was no difference in MPG.

Source

Can you use ethanol-based fuels for the BMW X5?

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:

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 BMW X5.

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 BMW X5, but it won’t be a danger in the short term. However, it can only be used for BMW X5 models from 2006 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 BMW X5 if you have a flex-fuel kit.

FAQs about gas for the BMW X5

If you have any more questions about which gas type to use for your BMW X5, take a look at these FAQs:

Final verdict

To summarize: You cannot use regular gas in the BMW X5.

You need mid-grade gas at a minimum, and it’s recommended to use premium gas.

BMW recommends premium gas to preserve the engine and ensure your X5 continues to drive for years to come.

Sure, in the short run, you might save a bit by using regular gas. But think about the long game: lower fuel efficiency and potential repair bills.

Suddenly, those upfront ‘savings’ might not feel so significant.

If you have any more questions, let us know in the comments!

Gas requirements for other BMW models

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

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

• BMW 3 Series gas type
• BMW 4 Series gas type
• BMW 5 Series gas type
• BMW X1 gas type
• BMW X3 gas type