Brent + INR Guardrails: OMC Margins & City Fuel Bills

In this piece:

The short

Direction: Lower Brent + steady INR widens GMM; retail bands tend to hold.
Sensitivity: ~₹0.40–₹0.60/L per US$1/bbl (diesel toward the higher end); ~₹0.50–₹0.70/L per ₹1 on USD/INR.
Lag: Retail adjusts with inventory timing; 2–3 week drift beats 24-hr spikes.
Policy: Excise/VAT edits or band management can override cost maths.
Households: Use city bands + km/L to budget; EV per-km stays cheapest on energy alone.

Pump price (₹/L) ≈ landed product cost (Brent × crack × FX) + freight + OMC opex + dealer margin + central excise + state VAT.

Cracks: Gasoline/diesel spreads vs Brent; diesel crack swings compress GMM quickly.
FX pass-through: Most inputs USD-linked; INR depreciation raises landed cost.
GMM (₹/L): Pump price net of taxes − landed cost − logistics/opex.

Operator tip Hedge key inputs on a rolling 3-week window; avoid one-day fixes around data prints.

Scenario	Brent (US$/bbl)	USD/INR	Petrol GMM (₹/L)	Diesel GMM (₹/L)	Read
A	60	83	4.5–6.0	5.0–6.5	Comfort; room to hold retail bands
B	70	84	3.0–4.5	3.5–5.0	Neutral; cracks decide
C	80	86	1.0–2.5	1.5–3.0	Tight; under-recovery risk pockets
D	75	88	0.5–2.0	1.0–2.5	FX pain > crude

Rule of thumb: Diesel crack spikes can negate a benign Brent print—watch spreads.

City	Petrol (₹/L)	Diesel (₹/L)	Note
Delhi	102–105	90–93	Baseline bands
Mumbai	106–110	93–97	Higher VAT/cess
Bengaluru	102–106	88–92	Recent resets
Chennai	101–104	92–95	Levy mix