From the Apex · Blind Spot · 2026-09-06

Regular petrol is 95 octane now. The only thing premium has left to sell is less ethanol.

Since April every pump in India has had to sell E20 at a minimum 95 RON. That deleted the octane argument for premium petrol overnight and left one honest reason to pay more, which in Delhi costs ₹65.23 a litre.

• Since 1 April 2026 every pump in India must sell E20 petrol at a minimum 95 RON. The 95-octane branded grades charge extra for a number you now get as standard.
• Octane is not power. It is how hard the fuel resists igniting on its own when the engine squeezes it. If your engine never knocks on regular, a higher number changes nothing.
• The only premium fuels still selling something real are the 100-octane grades, which advertise 0 ethanol. In Delhi that works out to ₹65.23 extra per litre.
• Two oil companies published an ethanol figure for their own 100-octane petrol, got it wrong, and had to correct it. None of them publish the ethanol content of their branded grades now.

A graphic doing the rounds in Indian car groups grids up the brands, their octane numbers and their ethanol percentages. Half of it is out of date. The rest has no source.

91 RON died in the spring of '26

On 17 February 2026 the petroleum ministry notified that oil companies must sell petrol blended up to 20% ethanol at a minimum 95 RON. It took effect at every outlet in the country on 1 April.

Until then the pump default everywhere was 91 RON. That is where the graphic's numbers came from, and for years they were right.

Now hold them against the price board. IndianOil's XP95 is 95 octane. HPCL's poWer95 is 95 octane. BPCL sells Speed as "95+ Octane". Three premium grades named after the number the cheap hose has to clear by law.

Autocar India had a lab run octane on Mumbai samples last September. Regular E20 came back at 98.2 RON, XP95 at 98.8.

The column nobody publishes

Octane is on every oil company's product page. Ethanol content is on none of them: not a percentage, not a range, not a footnote.

BPCL contradicts itself on its own site: the Speed Fuels page sells Speed as "95+ Octane", the Speed FAQ still puts it at 91. One of those stopped being true in April.

One lab has actually looked. Autocar ran gas chromatography on seven fuels bought in Mumbai:

Regular came back at 20.86% ethanol, XP95 at 19.88%, which is the mandate. The grade you pay ₹7.12 a litre extra for is the same blend as the hose next to it. XP100 really is ethanol-free, but not additive-free: 12.38% of it is MTBE, and that is what does the octane work.

The MTBE is why the forum tests get XP100 wrong: ethanol sensors and the water-in-a-jar trick react to oxygenates in general, so they find ethanol in a fuel that has none. IndianOil and HPCL each posted 10% ethanol for their own 100-octane grades, and both corrected it after Autocar challenged them.

Nobody has measured HPCL's poWer grades or BPCL's Speed. The percentages sitting against them in the viral graphic have no source at all.

What octane actually does

Octane is not extra energy. A litre of 100 RON has no more push in it than a litre of 95. It measures how hard the fuel resists igniting on its own when the piston squeezes it, before the spark plug fires.

Every modern engine has a knock sensor. It advances the ignition timing until it hears knock, then pulls it back. If your engine never knocks on regular, there is nothing for a better fuel to fix. If it is a high-boost engine that has been quietly pulling timing, better fuel lets it stop, and you get that power back.

The only instruction that matters is the minimum RON in your handbook, and almost nothing on sale in India asks for more than 95. Everything naturally aspirated, the Swift, Baleno, Altroz, the i20 1.2, the 1.5 City, the 1.5 Creta, was mapped when the pump handed it 91. The mandate already over-feeds it.

The ethanol worry

Cars built from April 2023 had to be E20 material compliant. Before that the standard was E10, which is why so many older handbooks say so.

The concern is the plumbing, not the engine. A 2021 ARAI study found some rubber compounds, NBR-PVC blends and epichlorohydrin among them, degraded faster on E20 than on plain petrol. Those materials are the fuel hoses, seals and O-rings. The study stops short of predicting failures.

Against that, the petroleum ministry said in July that Maruti serviced 2.84 crore vehicles last financial year, roughly 1.5 crore of them never certified for E20, with no ethanol-linked corrosion reported. It concedes a 3% to 5% economy loss in some cars, which is ethanol carrying less energy, not an octane effect.

A small, slow, real risk, then. The question is what hedging against it costs.

What the hedge costs

₹52,184 a year to keep ethanol out of a set of hoses and seals, on a car that has been drinking E15 or stronger for three years already. Replacing that plumbing once costs a fraction of one year's premium.

The middle rungs do not buy you even that. Only the 100-octane grades take you to zero ethanol, and in Delhi that is ₹65.23 extra a litre, every litre, for as long as you own the car.

So, which one is yours

• 1.2 naturally aspirated hatchback: regular petrol. There is nothing in the expensive tank for you.
• Turbo-petrol SUV, the 1.0 and 1.5 crowd: regular, unless the handbook says otherwise. If you want the detergent additives, an occasional branded tank covers it.
• Performance car: read the handbook. If it asks for 98 RON or more, the 100-octane grades are the only fuels on sale here that guarantee it. BPCL lists 73 Speed 100 outlets in the country, 20 of them in Delhi, so check the map first.
• Pre-2020 car, worried about ethanol: do not buy your way out one tank at a time. Have the hoses, seals and O-rings checked at the next service and spend the money once.

axler8's take

Premium petrol here was sold on the gap between 91 and 95. That gap closed on 1 April and not one dispenser changed its signage. Two real products are left: a detergent additive package, and ethanol-free 100-octane for the few cars that need it. Everything in between is a number you already own, priced as though you do not.

Read your handbook.