Guide
Premium Fuel Explained — 95 vs 98, and Is It Worth It?
Premium petrol costs more per litre than regular 91 — sometimes a lot more. Whether it's worth it comes down to one thing: what your car's manufacturer specifies. Here's what 91, 95 and 98 actually mean, and when paying for premium makes sense.
What do 91, 95 and 98 mean?
The numbers are octane ratings (RON — Research Octane Number). Higher octane resists "knock" (uncontrolled combustion) better, which lets engines designed for it run higher compression and more aggressive timing.
- 91 — regular unleaded (ULP)
- 95 — premium unleaded (PULP)
- 98 — premium, the highest octane commonly sold in Australia
Octane is about knock resistance, not energy or power on its own. Full explainer: What is RON?.
Is 98 worth it?
It depends entirely on your car:
- If your manufacturer specifies 98 — yes, use it. Running lower can cause knock and, over time, engine damage.
- If your car is happy on 91 or 95 — 98 usually delivers little you'll notice, and rarely pays back its price premium.
- If your car recommends 95 as a minimum — 95 is fine; 98 is optional.
Some modern turbo and high-compression engines can adjust their timing to take advantage of 98 and return slightly better economy or performance — occasionally enough to offset the extra cost, but usually not.
Does premium petrol give better fuel economy?
Only in engines built to exploit the higher octane. In an engine designed for 91, filling with 98 doesn't add energy — the fuel's energy content is broadly similar — so you won't get meaningfully better economy. Where a car is tuned for premium, using it can unlock the economy and performance the maker intended; using less than the minimum does the opposite.
98 fuels also tend to carry more cleaning additives, which some drivers value for engine cleanliness.
Can I use 91 in a car that recommends 95?
If 95 is a recommendation, occasional 91 is usually tolerated by modern engines (they pull timing back to avoid knock), though you may lose a little performance and economy. If 95 or 98 is a hard minimum requirement, don't drop below it. When in doubt, follow the fuel filler flap and owner's manual — see Which fuel for my car?.
95 vs 98 — which should I choose?
| 95 (PULP) | 98 (Premium) | |
|---|---|---|
| Octane | 95 RON | 98 RON |
| Best for | Cars specifying 95 minimum | Cars specifying 98, or seeking max knock margin |
| Price | Cheaper of the two | Usually 5–15c/L more than 95 |
| Additives | Standard premium | Often higher detergent additive levels |
If your car only needs 95, the jump to 98 is generally optional. If it needs 98, 95 isn't a substitute.
Compare 95 and 98 prices near you
Open Petrol Australia, set the fuel filter to 95 or 98, and the map ranks every station by live price. The Insights All fuel types view shows 91, 95 and 98 together so you can see exactly what the premium is costing you today.
Related: What is RON? · Which fuel for my car? · E10 fuel explained
See premium prices near you — download Petrol Australia for iPhone and Android at petrolaustralia.com.au.