High octane
Asked by Vin Pham
WOULD Shell's new 100 RON Optimax Extreme be safe for my 1999 Honda Integra Type R? I have discovered that ethanol is not recommended for my car because there has been no long-term testing. Do you think E5, with 5 per cent ethanol, could be used in my car, or should I just stick with the normal 98-octane fuel?
Answered by CarsGuide
23 Dec 2005CARMAKERS take a conservative view on things such as this. They are reluctant to say it can be used safely because they don't have the test results to prove it. If they recommend it and a problem develops, they can be liable for the repairs, so it's easier for them to advise against using it. I don't believe the new higher-octane Optimax with 5 per cent ethanol will cause a problem. I also believe you would be safe using a 10 per cent ethanol blend. Honda specialist Adam Kovarik reckons the best fuel is Mobil 8000, which is a 98-octane fuel. He says engines run smoother and perform better, and spark plugs seem to last longer on the Mobil fuel.
