Auto Trader NZ
Published 21 February 2025
If you’ve ever stood at the pump wondering whether to fill up with 91 or 95-octane fuel, you’re not alone. Many drivers question whether premium fuel is worth the extra cost or if 91 does the job just fine. Let’s break it down in a simple, no-nonsense way so you can make the best choice for your vehicle and your wallet.
What’s the Difference Between 91 and 95 Octane?
The key difference between 91 and 95 octane fuel is their resistance to knocking (also known as pre-ignition or pinging). Both are petrol, but higher octane fuels can withstand more compression before igniting, which is essential for high-performance and turbocharged engines.
91 Octane (Regular Unleaded)
✅ Most commonly used fuel in NZ
✅ Cheaper at the pump
✅ Suitable for most non-performance vehicles
✅ Readily available everywhere
🚫 Not ideal for high-performance or turbocharged engines
🚫 Can lead to engine knocking in vehicles that require premium fuel
🚗 Popular models: Toyota Corolla, Honda CR-V, Mitsubishi Outlander
95 Octane (Premium Unleaded)
✅ Higher resistance to knocking
✅ Recommended for many European and performance cars
✅ Can improve engine efficiency in vehicles that require it
✅ May provide better fuel economy in some cases
🚫 More expensive per litre
🚫 No major benefits for cars designed to run on 91
🚗 Popular models: Audi S3, Subaru WRX, Toyota 86.
Does Using 95 Octane Improve Performance in Any Car?
A common myth is that using 95 octane in a car designed for 91 will boost performance and fuel economy. The reality? If your car is tuned for 91, using 95 won’t make a noticeable difference in power or efficiency. However, if your car requires 95 (or higher), using 91 can lead to engine knocking, reduced efficiency, and potential long-term damage.
What Does Your Car Need? Check the Owner’s Manual
The best way to determine which fuel is right for your car is by checking the owner’s manual or the sticker inside the fuel cap. If it says 91, then stick with it. If it recommends 95 or higher, don’t cheap out with 91—it could cost you more in repairs later. If unsure, this information is usually found on the fuel flap or in the owner’s manual.
Is It Ever Worth Paying Extra for 95 Octane?
It depends. If your car runs on 91, upgrading to 95 won’t provide significant benefits. However, if you drive a turbocharged, performance, or European vehicle that requires 95, then it’s absolutely necessary.
When to Consider 95 Octane:
- If your car manufacturer recommends or requires it.
- If you drive a high-performance or turbocharged vehicle.
- If you experience engine knocking with 91.
- If you want to maintain long-term engine health in a vehicle tuned for higher-octane fuel.
The Cost Factor
Fuel prices in New Zealand can be unpredictable, but 95 octane is always more expensive than 91. On average, you might pay 10-15 cents more per litre for 95. If your car runs perfectly fine on 91, switching to 95 is an unnecessary expense.
Final Verdict: Stick to What Your Car Needs
For most drivers, 91 octane is the go-to choice—it’s cheaper and perfectly fine for most standard vehicles. If your car manufacturer specifies 95, don’t risk using 91, as it could lead to engine problems over time. At the end of the day, using the right fuel for your engine is the smartest way to keep your car running smoothly without wasting money at the pump.
So, next time you’re at the fuel station, check that fuel cap, fuel up wisely, and hit the road with confidence!
