Need Advice: Speed / Xtra Premium Petrol Vs Normal Petrol

[carcommentor]

Re: Query regarding petrol rating and effectiveness branded petrol

Hello friends and fellow motorists

I hope this is the correct section for my queries.

I need a little clarification on the following two matters:

1. What is the octane rating of unbranded petrol (normal petrol) sold by IOCL?

2. Is the Xtra premium petrol sold by IOCL is any way beneficial for the engine and does it really improve the mileage (for TATA Zest specifically, as it has turbocharged engine, and that's what I drive at present)?

Thank you all.

Both are MG91 grade. The RON (Research Octane Number) is same for both- 91.
Xtrapremium apparently has some additives to clean the engine but I couldn't find details of the additives. You should stick to fuel mentioned in you car manual. Xtrapremium definitely doesn't improve the mileage. In fact, even higher octane fuels (in normal cars - not high performance cars) don't improve the mileage as most modern engines have knock sensors which ensures no pre-ignition happens, so there is no need for higher octane.