We’ve written extensively about the Acura RDX, its capabilities, and various features on this blog. Today, we will talk about what fuel this SUV needs and what fuels are strictly prohibited. Let’s start with a quick answer:
All generations of the Acura RDX manufactured since 2006 take premium unleaded gasoline with an octane rating of 91. Regular gasoline with an octane of 87 or higher may be used temporarily but will cause decreased performance. The use of fuel with an octane lower than 87 is strictly forbidden and will result in engine damage.
However, that doesn’t tell the whole story. Below we’ve outlined recommendations and requirements for different kinds of fuels and fuel additives. We’ll also go into detail about the compatibility of the RDX with oxygenated blends. Furthermore, we discuss the tank size of these generations. Read on!
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As you read the use of premium gasoline for teh Acura RDX is strongly advised by Acura. However, many people wonder if using fuel with an even higher octane rating isn’t a better idea. The reasoning behind this is that premium octane with a rating of 93 or even 95 improves the performance of the car even more and may also be preferable in terms of the lifespan of the engine and the fuel system.
However, this is not the case. We always recommend you to follow the instructions of the Acura that are given in your owners manual. The use of premium gasoline with a hihger than recommended octane level is useless. This is because an engine is designed specifically for a certain octane level (in this case, 91).
With 91 octane the Acura RDX will run as well as it can. Increasing the octane level will simply waste money instead of improve performance.
However, please keep in mind that lowering the octane level does have consequences. More on that in the ‘engine knock after refilling’ subheading.
Another aspect we need to talk about is the use of reformulated gasoline in the Acura RDX. Reformulated gasoline is gasoline that’s designed to burn more cleanly then non-reformulated gasoline. This kind of gasoline first became mandatory about two decades ago in California.
Since then, it has spread across the USA and now it’s mandatory in 19 areas. The question therefore arises if this is preferable for the RDX. Luckily, we’re happy to inform you that using reformulated gasoline is advises by Acura since it is better for the air quality in your region.
Furthermore, using reformulated gasoline does not have any adverse effect on your car in terms of performance, fuel economy or lifespan. Also, reformulated gasoline doesn’t cost any more then non-reformulated gasoline.
Also read: The Exact Bolt Pattern Of An Acura RDX
Another hot topic is the use of oxygenated blends of gasoline such as the ones that contain ethanol or methanol. These blends are typically sold during winter because they provide easier starting for the engine. However, there are strict guidelines you have to follow when using these blends. These are as follows:
- Methanol cannot be used with any generation of the Acura RDX.
- Ethanol can be used with the 2008 – 2011 generation of the Acura RDX as long as it does not exceed 10%. RDX’s manufactured after 2011 can use ethanol with a maximum percentage of 15%.
Using methanol or more than 10-15% ethanol will result in severe engine damage that’s characterised by the following symptoms:
- Poor accelaration
- Check engine light
- Engine knock (more on that later)
Gasoline With Additives
The use of additives is also something that needs to be discussed. These days it’s very easy to buy additives that are marketed as performance enhancing or that supposedly clean your engine. These additives are mixed into your fuel.
However, Acura strongly recommends against the use of these additives. The reason for this is that additives can contain materials such as silicon or metallics that will damage the negine and the fuel system. Furhtermore, they will also increase the amount of deposits in your engine.
Instead, Acura advises you to buy gasoline that has all the right additives already mixed into it. This is done by finding TOP TIER gas retailers. These certified retailers sell gasoline that’s safe to use with the RDX, it provides optimal performance and cleans the engine. Find these retailers at toptiergas.com.
Engine Knock After Refilling
A slight knocking sound of the engine is a completely normal occurence in day-to-day use. This is especially true when the RDX is challenged such as when towing or driving up a hill. However, there are instances where loud knocking of the engine is a severe problem that should be dealt with immediately.
As we know by now, the RDX is a car that needs 91 octane. However, they can also temporarily run on 87 octane is 91 is not available. However, it’s important to listen to your engine when you do so. Lower than recommended octane levels can result in heavy knocking of the engine. If this occurs it’s advised to stop the car immediately and contact your dealer.
The car doesn’t seem to be able to handle lower than recommended octane levels. Therefore, it needs to be drained together with a replacement of the fuel filter and the disconnecting and reconnecting of the battery to reset the cars memory.
Also read: 14 Common Problems Of An Acura RDX
Fuel Tank Size Per Generation
- Acura RDX manufactured between 2008 – 2011 have a fuel tank capacity of 18 gallons or 68 liters.
- Acura RDX manufactured between 2011 – 2018 have a fuel tank capacity of 16 gallons or 60.5 liters.
- Acura RDX manufactured after 2018 have a fuel tank capacity of 17.1 gallons or 64.7 liters.