Most engines cannot use unleaded 98 because they are designed for unleaded 95. In order to understand this fact, you need to know what the number means. This method is much more environmentally friendly. If 95 octane petrol is used, those costs rise to around $2,330 per year while using 98 octane fuel would see costs increase again to around $2,410 per year. If you used 95 petrol instead, it would explode too quickly under the pressure. Durchschnittliche Bewertung 4.5 / 5. Saving fuel is much easier if you adapt your driving behaviour and follow these rules. If the combustion of the fuel mixture is uncontrolled, the piston is braked in its upward movement. You can also run the vehicle on 95 octane fuel if you like and it will likely give you a small increase in performance and improved fuel consumption but ... She always fills it up with 98 or 95. Do you know friends who regularly fill their tank with unleaded 98? It can run 91 RON Octane and can be mixed with 95 without problems. If you don’t know what fuel you should be running your vehicle on, seek advice from the local dealer that services your brand of car. 24-hour AA Roadservice: 0800 500 222 The mixing ratio is then adjusted until the fuel mixture has the same knock resistance as the fuel sample. While it might seem that using higher octane petrol than specified might be ‘nice’ for your engine, or that it could ‘unleash some previously undiscovered power’ within the engine, you are not really doing anything for it at all. 95 petrol works as well, but if your engine is powerful, it will use higher pressures that 95 petrol may not be able to withstand. It can’t hurt your engine if you use a higher octane fuel. 24-hour AA Roadservice: 0800 500 222 "I see no benefit in mixing.". I'm not sure where to look this up online, but I'm sure you good people do. It's a common belief that premium petrol gives your engine more power. No votes so far! I've just bought a Japanese 2008 Honda Edix 2.0Litre The dealer says that all cars run better on 95, I'm skeptical, as I've just moved on from a very similar 2003 Honda Odyssey that I've run for ten years on 91. The reason for this is often a too low knock resistance of the petrol, which is classified in the value of the octane number. You may also find the octane specification printed on your gas cap. This is a space where subscribers can engage with each other and Globe staff. It is okay for you mix different 93 octane and 95 octane fuel as long as your vehicle octane number requirement isn’t too far below or above 94 octane, although it is okay to give a higher octane fuel than it is required because it will do nothing to the engine. Occasionally I'm out of range of BP Ultimate 98 and need petrol, is there any harm in filling up half a tank of 98 with the Premium 95? Switch off the engine at a traffic light or level crossing. If the vehicle is designed to run on 91, you're usually best to stick to that as there's generally no benefit in running a more expensive, higher octane fuel. Thanks. Mobile: *222, Cars Yesterday I accidently fill it up with 40L of 91. If you don’t know what fuel you should be running your vehicle on, seek advice from the local dealer that services your brand of car. 98 petrol does cost significantly more: for a typical car, filling with 98 petrol can be about $18 more than using 95. If the fuel flap tells you to use 98, that’s what you need to do. Car companies, some experts and Consumer Reports itself say you should use what the manual recommends – the site notes that Bartlett's view is personal. Hi there. I have a Mazda Axela 2009 2L. Thanks for your prompt reply and advice. Customer Contact Centre: 0800 500 444 If you are looking to give feedback on our new site, please send it along to, To view this site properly, enable cookies in your browser. Wherever you refuel with unleaded 95 in Switzerland, you can also buy unleaded 98. The octane number of the sample corresponds to the percentage of isooctane in the control mixture. However, while it’s possible to mix these fuels, experts recommend sticking to the octane recommended for your car, whether 95 or 97/98, to ensure efficient performance and avoid engine damage. If premium is recommended, rather than required, it means that you can use regular – but you'll lose a little horsepower. "Remember, this 'premium' recommendation is not coming from your mother, but rather an auto maker looking for marketing-friendly bragging rights," says Consumer Reports deputy online editor Jeff Bartlett in a blog on the magazine's site. Designed by drivers for drivers, this all-in-one app lets you receive the latest traffic updates, gives you access to live traffic cameras, and helps you manage LTA and vehicle matters. What do you get when you mix regular with super premium? But this does not mean that putting 98 petrol in a normal-performance engine will give you greater power. 351 King Street East, Suite 1600, Toronto, ON Canada, M5A 0N1, Automatic transmissions gear up for better fuel efficiency, Actress loves her tricked-out Range Rover, Due to technical reasons, we have temporarily removed commenting from our articles.