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Types Of Gas A BMW X5 Can Use (Explained)

When a car buyer decides which car to buy, a pretty prominent amount of focus is given to the car’s fuel economy. Sometimes it becomes the deciding factor for car buyers in deciding which car to purchase. We will see how the BMW X5 lines up on the expectation of fuel economy being an SUV.

BMW recommends AKI 89 or RON 94-95 as the best fuel grade for the BMW X5 code-named G05. This is the 4th generation of X5. BMW, however, warns of a knocking sound when starting the vehicle in hotter climates with zero damage to the engine. It is advisable to use RON 95 and above for better performance.

Since fuel grades/types are rated based on their octane content, it is essential to see how the fuel grade used for a car plays out in the longer run. Octane rating denotes the measure of a fuel’s stability. In a nutshell octane rating of a fuel is directly proportional to the engine’s performance and life. Below we’ll discuss the fuel of a BMW X5 in great detail. Read on!

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Also read: How Many Miles Can A BMW Last? (17 Models Analyzed)

Fuel Requirements Based On Engine Type

2018 to present

The BMW X5’s 4th generation comes with a 3.0-liter inline-6 turbocharged engine tuned to produce a healthy 300 horsepower. It is an SUV, and with such a powerhouse at the front, RON 94-95 is what BMW suggests as a bare minimum. Based on feedback from X5 owners, the RON 94-95 does pretty well for the 3.0-liter turbo six engines.

Apart from the base models, X5 sDrive40i and X5 xDrive40i, the X5 is also offered in X5 M50i and X5 M variants with the 4.4 liters 8 cylinder turbo tuned to 523 HP for M50i and 617 HP for the X5 M. We would strongly recommend higher octane grade fuel for the M variants. The power and life of this 4.4-liter powerhouse are greatly enhanced if run on RON 96-98.

Another variant offered by BMW is the X5 xDrive 45e. This has the same 3.0-liter inline-six turbocharged engines with the base sDrive40i and xDrive40i. Mated with an electric motor, it can produce a staggering 282 HP independent of the electric motor. The electric motor adds another 111 HP bringing the total output to 393 HP. RON 94-95 suits this one the best.

2013 to 2018

The third generation of X5 codenamed F15 was introduced with both Diesel and Petrol engines. It was presented with a 450 HP V8 engine for xDrive50i and two 6-cylinder turbo-diesel engines putting out 258 HP for the xDrive30d with dual turbos and 380+ HP for the triple turbo M50d M Performance. BMW later introduced xDrive40D and xDrive35i.

The fuel types suggested by BMW for all engine types remain standard across the board. For diesel engines, the sweet spot BMW wants the owners to land at is less than 5% biodiesel content, and for the petrol engines, the bare minimum is AKI 89, which is RON 94-95 in American English.

For the petrol variants, BMW suggests AKI 89, which is equivalent to RON 94-95 as a minimum allowed octane grade. This, according to BMW, is likely to produce knocking sounds when starting in hotter climates but won’t cause any damage to the engine. Therefore, it is safe to conclude that a better option is RON 96-98 for these engine types.

According to BMW, the diesel engines are produced for use with low-sulfur diesel. BMW suggests using diesel with less than 5% of biodiesel content. This is also referred to as B5. For colder regions where temperature nose-dive below 10 degrees, Number 1 is the better choice. For other areas, Number 2 can also be used with confidence.

2007 to 2013

The 2nd generation BMW X5 codenamed E70 for the first year came in two variants. xDrive 3.0 si and xDrive 4.8i. The 3.0 produced 268 HP, and the 4.8 had 350 HP. BMW suggests using RON 94-95 for both of these engines with knocking sounds at engine startup in hotter climates. This behavior, according to BMW, does not affect the engine life in any way.

Later, the terminology was changed, and the 3.0i was changed to 30i and 4.8i to 48i for the 2009 and 2010 model years. In 2011 BMW introduced the new xDrive35i and xDrive50i. These engines produced 302 HP and 401HP, respectively. For all petrol engines, BMW suggests RON 94-95 as the bare minimum fuel grade.

The X5 M had a 547 HP engine with aggressive handling and whatnot. Although BMW suggests RON 94-95 as the minimum fuel grade, we have come across owners using RON 96-98 on these variants, resulting in higher performance numbers and longer engine lives.

The diesel variants for the X5 included 3.0d, later called 30d producing 232 HP, and 3.0sd later called 35d with an output of 282 HP. BMW added a twin-turbo to the 35d in 2009, getting an output of 265 HP. The 40d in 2010 offered 302 HP, with the M50d putting out 376 HP.

BMW suggests the use of low-sulfur diesel for its diesel vehicles. BMW recommends using fuels with less than 5% of biodiesel content. More commonly known as B5, this type of fuel has up to 5% biodiesel content and is safe for use in BMW manufactured diesel vehicles.

1999 to 2006

The first generation of the X5, also called the E53, was offered for sale from 1999 till 2006. The engines offered were a 3.0 liter 228 HP engine for the 3.0i, a 4.4 liter 282 HP engine for the 4.4i, a 342 HP 4.6 liter for the 4.6is, and a 355 HP 4.8 liter engine for the 4.8is. There was a 3.0-liter diesel engine as well for the 3.0d variant.

For all the petrol engines, BMW engineers recommended AKI 93, which is RON 93. BMW did not recommend anything below that for the X5 petrol variants as it had a likelihood of poor performance and reduced engine lifespan. Furthermore, since the X5 was just being introduced, likely, BMW didn’t have sufficient data to suggest anything below RON 93.

BMW doesn’t clearly state the type of diesel to be used for the 3.0d variant. For diesel variants, BMW always suggests using low-sulfur diesel fuel types. A standard rule of thumb is to use Number 1 type for regions with less than 10-degree temperatures, and for the others, Number 2 will do well.

Also read: How Well Does A BMW X5 Drive In The Snow? (Answered)

What Types Of Gasoline Can And Can’t Be Used?

In addition to regular gasoline, a wide variety of other fuel types are also available today. To see the best fit for your BMW X5, let’s dig in further.

Reformulated Gasoline

Reformulated gasoline burns greener and cleaner than regular fuels. It ascertains the reduction in smog-formation and emits less toxic pollutant fumes while burning. For regions having lousy air quality, the use of reformulated gasoline has been somewhat regularized. The RFG fuel type is nowhere to be found in the BMW line of recommended fuels.

Although BMW wants its car owners to get the best fuel type, some drivers still prefer to opt for RFG. One thing that should be noted is the probability of warranty voidance if a BMW owner opts for RFG over regular gasoline since it is not on the list of recommended fuels by BMW for its vehicles.

Gasoline/Oxygenated Blends Or E-85

Oxygenated blends are nothing new. Many fuel suppliers have started offering oxygenated blends of gasoline. E-85 being among one of the most popular types, is in use today by many drivers. This is mainly a go-to choice for owners of cars with a higher focus on performance and a lesser emphasis on fuel economy.

The E-85 type is designated due to the presence of 85% ethanol and 15% regular gasoline. BMW does not recommend using the E-85 oxygenated blend in their vehicles. For BMW vehicles, the recommended mix is 25% ethanol at the max. The 25% ethanol to be used as per BMW should also meet the below quality requirements:

  • US: ASTM 4806–xx
  • CAN: CGSB-3.511–xx
  • xx: comply with the current standard in each case.

Sometimes manufacturers make it very clear in case their vehicles are E-85 compatible or not. A badge or an E-85 mark on the fuel cap is what you should be looking for if you want to determine your vehicle’s E-85 compatibility.

With BMW not recommending the E-85 fuel type, if the driver wants to opt for it, there are certain precautions to be mandated before use. These are:

  • Do not mix or switch different fuel types
  • Add at least 5 gallons at the time of refueling your vehicle
  • After adding the fuel the engine should be in use for at least 5 minutes after refueling before switching off

Gasoline With Added Materials

Since fuel is an engine-trotter, many materials can be blended with fuel to get different types of benefits such as engine cleaning, residue removal, engine life longevity, etc. The additives mainly used include anti-corrosion additives, detergents, and so on, depending on the intended outcome of such addition.

BMW strictly refrains from suggesting the use of such types of gasoline for its cars. Yes, some drivers want to ensure their engines run clean and pollutant-free, but that’s not on the agenda of BMW’s suggestions to its car owners. BMW, however, bravely suggests using RON 96-98 higher octane grades for its vehicles.

Gasoline With MMT

US EPA website states that up to 1/32 grams per gallon of manganese may be allowed for vehicles. Methylcyclopentadienyl manganese tricarbonyl (MMT), an octane enhancer, can be used according to the EPA in cars.

BMW, however, does not suggest the use of gasoline with MMT in any of the BMW X5 variants.


Biodiesel is mainly sourced from soybean oil and is a biodegradable alternative fuel. It can also be achieved from other sources such as yellow grease, even canola in some cases. Although BMW does not openly suggest the use of biodiesel, it is safe to conclude that since all diesel engines are biodiesel compatible, one may opt for biodiesel in BMW vehicles as well.

B2, B5, and B20 are the most commonly used types of biodiesel fuels. Ideally, the  B5 and below is the safe zone according to BMW’s owner manuals for BMW X5. Anything between B6 – B20 tends to shorten the service intervals inevitably because above B5 is certainly not a safe zone for your engine.

What If I Hear A Knocking Noise From The Engine After Refilling

For the BMW X5, BMW states in the owner manuals that using the RON 93 means the engine makes knocking sounds in hotter climates. This is something every driver from novice to pro hates alike. However, the knocking sound can either be the result of a weak engine or lousy fuel quality.

Therefore, it is to be borne in mind that to avoid such engine behavior, it is advisable to use a type of fuel with a higher octane rating since it allows for better engine performance and life.

Also read BMW X5: Battery Problems, xDrive35i Problems, Diesel Problems

Does the BMW X5 Have Good Gas Mileage?

The first generation of BMW X5 (E53) was offered with four engine types in the petrol line up. The worst of them on fuel economy was the 3.0i. Surprisingly the 4.8i turns out to be the best of them all, with the worst combined rating of 14 MPG. A likely reason is an aggressive foot on the gas pedal to make up for the power deficiency.

EngineLowest Combined MPGHighest Combined MPG
4.6i 14 20

The second-generation BMW X5 (E70) was offered for sale from 2007 to 2013. The variants offered by BMW for the E70 were better in fuel economy than the first generation E53 variant. The best variant turns out to be the xDrive35i that did 16 MPG on its worst day and 23 on its best. However, the worst was the M variant ranging from 12 MPG to the best number of 17 MPG.

EngineLowest Combined MPGHighest Combined MPG

The F15 was offered from 2013 till 2018 and was one of the best X5s in terms of fuel economy. The 40e was the best as it supported an electric motor allowing one to achieve a maximum of 56 MPG on its best day. The worst of the pack was the M version doing 21 on its worst day with 25 MPG at its best.

EngineLowest Combined MPGHighest Combined MPG
xDrive40e24 (gas only)56 (gas + electric)

The current version of the BMW X5 (G05) is not as good on fuel economy as the third generation. The 45e offers the best fuel economy keeping in mind that it has an electric motor complementing the gasoline engine. The worst is the M version, obviously because it is performance-minded instead of emphasizing fuel economy.

EngineLowest Combined MPGHighest Combined MPG
xDrive45e20 (gas only)50 (gas + electric)

What’s The Gas Tank Size Of A BMW X5?

For the first generation of BMW X5, the fuel tank capacity was 24.6 Gallons or 93 liters. Later on, the gas tank was reduced to approximately 22.5 gallons or 85 liters for the second and third-generation X5. The current generation of X5 has a capacity of 32.9 gallons or 125 liters approximately in total.

How Much Does It Cost To Fill Up A BMW X5

The most expensive state is California, where one gallon of gasoline is $4.388—moving to the cheapest state, Mississippi. Here the cost for one gallon of gas is $2.816. Texas also has the same price of $2.816.

To fill up the tank of the first-gen X5, you are looking at spending $107.94 in the most expensive state. For the second and third generation of the X5 with 22.5 gallons of fuel, you may be paying around $98.73, and the current generation with its 32.9 gallons will cost you $144.36 in California.

If you are in the state with the least fuel prices, like Mississippi or Texas, you will be spending around $69.27 for 24.6 gallons. Overall, the cost to fill up a BMW X5 falls somewhere between $69-$144.36. The prices vary depending on the type of fuel you prefer, the location from where you are getting your refill.