The Audi Q8, introduced in 2018, is positioned as Audi’s flagship SUV. Like most SUVs, amazing gas mileage isn’t exactly its specialty, and filling up the 22.5-gallon fuel tank can add up fast- especially if you’re using premium fuel.
But do you have to use premium fuel? What type of gas does the Audi Q8 take?
The Audis Q8 owner’s manual recommends premium fuel with a minimum octane rating of 91. That’s true across all generations of the Q8 except for the TDI diesel engines which require ultra-low sulfur diesel. While the Q8 can be operated using regular unleaded 87 octane, per the owner’s manual, engine performance will be reduced.
So while it’s certainly possible to fuel up with 87 octane and save some cash, the Q8 is a premium vehicle, with a premium engine designed for premium fuel so it’s not something I’d suggest making a habit of.
That’s enough to get you refueled and on the road but we’re about to go on a deep dive into everything Q8 fuel so stick around if you want to learn more.
Fuel Requirements Based On Engine Type For All Generations Of Audi Q8
The Q8 is one of Audi’s latest additions to its luxury SUV range, so unlike the many generations of the A8, we’re only looking at one generation of the Q8 which makes figuring out fuel requirements easier.
We’ll take a closer look at each engine type but if you want a quick look, you can check out this table:
| First Generation Audi Q8 (2018-Present) | ||
|---|---|---|
| Engine Type | Fuel Requirement | Notes |
| 3.0L TFSI V6 Gasoline Engine | Unleaded Gasoline (87-93 Octane) | Minimum: 87 octane (87 AKI / 91 RON) Recommended: 91 octane for rated performance Best Performance: 93 octane Use TOP TIER Detergent Gasoline to reduce combustion residues. |
| 3.0L TDI V6 Diesel Engine | Ultra-Low Sulfur Diesel (ULSD) | Use ULSD to ensure engine health and emissions compliance. |
| MHEV (Mild Hybrid Electric Vehicle) System | Depends on primary engine type | Assists primary engine, especially during start-stop driving. Fuel type depends on the primary engine. |
First Generation Audi Q8 (2018-Present)
We see all the usual Audi options with the Q8: TFSI gasoline engine, TDI diesel, and the option for an MHEV system.
3.0L TFSI V6 Gasoline Engine
For the 3.0L TFSI gasoline engine in the Audi Q8, unleaded gasoline is a must to ensure the proper function of its catalytic converter. The owner’s manual indicates that the vehicle can operate on regular gasoline with a minimum of 87 octane (87 AKI / 91 RON).
However, Audi recommends using premium gasoline with at least 91 octane to achieve the rated horsepower and torque. But Audi doesn’t stop there, the manual for the Q8 goes on to say those looking for top performance should take things even further to 93 octane.
Audi also endorses the use of TOP TIER Detergent Gasoline to mitigate combustion residues in the engine and we’ve seen that across a lot of manufacturers because it really does work.
3.0L TDI V6 Diesel Engine
As with other Audi diesel engines, the Q8’s 3.0L TDI requires ultra-low sulfur diesel (ULSD). Regular diesel fuels might compromise engine health and emissions compliance over time. It’s always best to opt for the recommended ULSD to maintain optimal performance.
MHEV (Mild Hybrid Electric Vehicle) System
Audi’s MHEV system in the Q8 isn’t about changing the primary fuel source; it’s about complementing it. This mild hybrid system provides assistance, especially during start-stop driving, leading to fuel savings. The primary fuel type for the engine remains unchanged, so whether it’s a gasoline or diesel engine, stick to the fuel requirements as mentioned above.
If that’s not making sense to you, check out this video which does a great job explaining how the MHEV system works:
Does The Audi Q8 Require Premium Fuel?
The Audi Q8 owner’s manual recommends premium fuel with a minimum octane rating of 91 (91 AKI / 95 RON) for best performance. However, the owner’s manual also explains that if premium fuel isn’t available, then 87 octane (87 AKI / 91 RON) can work but with some reduction in performance. So the Q8 doesn’t absolutely require premium fuel but to get the most out of this vehicle you should be using it whenever possible.
Do Audi Q8s With The Mild Hybrid Electric Vehicle System Use Different Fuel?
Nope! Q8s with the Mild Hybrid Electric Vehicle (MHEV) system do not use different fuel.
The MHEV system complements the primary engine, aiding in fuel savings and efficiency during start-stop driving. The primary fuel type, whether gasoline or diesel, remains consistent with non-hybrid models. The MHEV focuses on enhancing efficiency, not altering the main fuel source.
Can I Use E85 In My Audi Q8?
No, you should not use E85 in your Audi Q8. The Audi Q8 is specified to handle gasoline with up to 15% ethanol content. E85, as its name implies, contains up to 85% ethanol.
Using fuels with higher ethanol content than the vehicle is designed for can lead to issues like corrosion damage, damage to plastic or rubber components in the fuel system, and reduced performance. For the Audi Q8, the acceptable ethanol content in gasoline is no more than 15%.
What Types of Fuels Can and Can’t Be Used in the Audi Q8
Let’s dive into what you can and can’t pour into your Audi Q8. To make things a little easier, I’ve put together all your fuel options in this table but you can read more about each option below:
| Fuel Type | Compatibility | Notes |
|---|---|---|
| Gasoline With Added Materials | Compatible | Prefer TOP TIER Detergent Gasoline. Avoid gasolines with metallic additives. |
| Gasoline With MMT | Not Specified | Can lead to deposits in the engine and damage the catalytic converter. |
| Gasoline with Alcohol or MTBE | Compatible with conditions | Max 3% methanol with >2% solvent; Up to 15% ethanol; Max 15% MTBE. Ensure 87 octane (87 AKI / 91 RON). |
| Methanol Blends | Compatible with conditions | No more than 3% methanol and more than 2% solvent. |
| Ethanol Blends | Compatible with conditions | Gasoline can contain up to 15% ethanol. Ensure 87 octane (87 AKI / 91 RON). |
| Flex Fuels | Not Compatible | Audi Q8 isn’t designed for flex fuels like E85. |
| Biodiesel | Not Specified | Not mentioned in the owner’s manual. |
| Reformulated Gasoline | Not Specified | Ensure it meets the octane requirements and doesn’t exceed ethanol/methanol limits. |
Gasoline With Added Materials
For the Audi Q8, unleaded gasoline is essential, and as with many manufacturers, they’re recommending the use of TOP TIER Detergent Gasoline. You’re safe with that but anything with a metal additive will wreck your catalytic converter, void your Q8’s warranty and pretty much ruin your day. So avoid those.
Gasoline With MMT
Audi explicitly advises against using fuels with metallic additives, and that includes MMT. If you want a functioning catalytic converter, leave this out of your tank.
Gasoline with Alcohol or MTBE
Here’s where things get a bit specific. The Audi Q8 can handle unleaded gasoline mixed with alcohol or MTBE (generally labeled as oxygenated compounds). However, there are conditions:
- The content should be no more than 3% methanol and should contain more than 2% solvent.
- For Ethanol (ethyl alcohol): Up to 15% ethanol is acceptable.
- For MTBE: No more than 15% MTBE.
- Always ensure the Anti-Knock Index is at least 87 octane (87 AKI / 91 RON).
Methanol Blends
The Audi Q8 can tolerate gasoline with a methanol content, but it’s crucial to ensure it’s no more than 3% and has over 2% solvent. Using gasoline with higher methanol content can lead to corrosion damage and degrade plastic or rubber components in the fuel system.
Ethanol Blends
Ethanol blends are quite common, especially in the U.S. For the Audi Q8, gasoline can contain up to 15% ethanol, but always make sure the Anti-Knock Index is at least 87 octane (87 AKI / 91 RON). Going as low as 87 octane isn’t going to give you a great performance but it can work in a pinch.
Flex Fuels
E85 has 85% ethanol, which is way over the 15% ethanol content that the Audi Q8 can handle. That means no flex fuels for the Q8.
Biodiesel
The Audi Q8, when equipped with specific V6 diesel engines, is approved for HVO (hydrotreated vegetable oil) use, a sustainable renewable fuel. Always refer to specific engine compatibility before using HVO.
Reformulated Gasoline
Audi generally maintains that as long as the fuel meets the Q8’s octane requirements and doesn’t contain prohibited additives, it should be compatible. With the Q8, reformulated gasoline with up to 15% ethanol is acceptable, given it has an Anti-Knock Index of at least 87 octane (87 AKI / 91 RON).
Does The Audi Q8 Get Good Gas Mileage?
Alright, let’s dive under the hood a bit. The Audi Q8 clocks in at about 17 mpg in the city and 21 mpg on the highway, according to the EPA.
For a car of its caliber, these numbers are pretty standard. Now, I’ve seen many luxury SUVs in my day, and the Q8’s fuel efficiency, while not breaking any records, holds its own in its class.
How Does The Audi Q8’s Gas Mileage Compare To Other Luxury Models
First up, the BMW X6. It edges out slightly with around 18 mpg in the city and 24 mpg on the highway. Close, but the driving experience might shift your preference and I prefer the Q8 over the X6.
Next, there’s the Mercedes-Benz GLE Coupe. Matching the Q8 in the city at 17 mpg but pulling ahead on the highway with 22 mpg. Still, sometimes that efficiency from Mercedes feels like it’s holding back a bit on the raw power.
Lastly, the Porsche Cayenne comes in with 19 mpg city and 23 mpg highway. It’s efficient, but remember, pushing its limits might see those figures adjust.
In the luxury SUV realm, mpg differences are often subtle. But for those of us with grease under our nails, it’s the combination of efficiency, performance, and feel that drives our choices. They’re all solid picks, but each offers its own unique ride and I’m more worried about that than a couple of bucks saved at the pump.
Closing Thoughts
The Audi Q8, being a premium vehicle, deserves premium treatment. Sure, the occasional 87 octane fill-up won’t spell disaster, but consistently fueling it with the recommended 91 octane will ensure your Q8 delivers the performance it promises.
It’s important to remember that while the nitty-gritty details about various fuel types and additives might seem overwhelming, it’s all about finding that optimal balance between performance, engine health, and, of course, your wallet. After all, if you’ve invested in a luxury SUV like the Q8, it makes sense to get the best out of it. But keep it simple and stick to premium fuel for the best results.
Hi! My name is Stefan; I’m the owner and lead writer at TheDriverAdviser.com.
I’m an active writer on this blog myself, as well as a novice car mechanic. For the really technical stuff, I find writers with experience as a mechanic or who have studied mechanical engineering.
Read more about our fantastic team on our about page!