Regular petrol from parco's refinery does have a higher octane value than regular petrol from other sources - from a scientific study. Total pumps get it from parco.
BUT if your vehicle doea not have a high compression engine, or a one tuned with crazy advanced ignition tables, then it would actually give you lower performance (and mileage) - from personal experience.
JDMs that knock heavy on regular fuel, try using total's regular petrol for one or two fills. Best part is that it carries no extra charge