Gasoline 95 or 98 on a motorcycle: which to use and why (2026 guide)

The question at every refueling

You arrive at the gas station, look at the pumps, and there it is, the usual question: 95 or 98? The short answer: whatever your bike's manual says. The long answer is what we're telling you here, without myths and with facts.

What octane rating is (and isn't)

The number (95, 98) indicates the octane rating: the gasoline's resistance to premature detonation, that "pinging" or knocking that damages the engine in the long run.

What it doesn't mean:

It's not more power on its own. A bike designed for 95 doesn't go faster with 98.
It doesn't "clean" the engine. Detergent additives depend on the gas station brand, not the octane rating.
It's not "better gasoline" at all. It's gasoline with different resistance to compression.

What your manufacturer says

The golden rule is in the owner's manual and, often, on a sticker next to the fuel cap:

"Minimum 95 RON" → use 95. Using 98 is a waste of money: the engine can't take advantage of the extra octane.
"98 RON recommended" → the engine has high compression or very advanced ignition. It will run with 95 (the ECU will retard ignition), but you'll lose some performance, and in the long run, it's not ideal.
Older bikes (pre-1992 approx.) → be careful: they were designed for leaded gasoline. What they need isn't more octane but a lead substitute additive or adapted valve seats.

Common examples

Type of bike	Typical recommendation
125cc scooters and low-compression A1/A2 bikes	95
Mid-displacement naked and trail bikes	95 (unless otherwise indicated)
High-compression sportbikes (R1, Panigale, S1000RR…)	98 recommended
Low-compression V-twin customs	95

What if my bike needs 98 and only 95 is available?

It's okay for occasional use. Modern engines have a knock sensor: the ECU detects knocking and adjusts the ignition. You might notice slightly less responsiveness, but you won't break anything with one tank. What you shouldn't do is consistently use a lower octane than recommended.

"Premium" gasoline with brand names: is it worth it?

Gas stations sell versions with additives (Repsol Efitec, Cepsa Optima, BP Ultimate…). They are usually 98 octane, and their real value lies in the detergent and anti-corrosion additives, not the number. If your bike requires 95, a 95 with good additives is a better buy than a basic 98.

E5, E10, and ethanol

In Spain, current gasoline is E5 (up to 5% ethanol), and E10 (up to 10%) is becoming more common. Key points:

Most bikes manufactured after 2000 can handle E10 without problems (check your manual).
Ethanol absorbs moisture and degrades old rubber: for classic bikes or those stored for months, E5 is better, and fill the tank completely before storing it.
Ethanol has less energy: with E10, fuel consumption increases by 2-3%.

How much you can save

The difference between 95/98 is usually 10-15 cents per liter. For a 15-liter tank, that's €1.5-€2 per fill-up; about €60-€100 per year for average use. If your bike is designed for 95, that money is pure savings with no downsides.

And if you want to save even more: at MotoCorner, you can find a locator for cheap gas stations near you, with official updated prices from the Ministry. The difference between the expensive and cheap gas station in your area is usually greater than the difference between 95 and 98.

Summary in 4 rules

The manual rules: use the octane your bike requires, no more, no less.
Higher octane ≠ more power if the engine isn't designed for it.
Additives matter more than the number: good 95 is better than basic 98.
Save at the gas station, not on octane: use the price comparison tool and refuel where it makes sense.

Content created with AI support and reviewed by the MotoCorner team.