PH Mobility Fuel — Regime Analysis · 2020–2026

Diesel isn't a trend line. It's a shock series. A home-charged EV is the stable floor beneath it.

Over six years NCR pump diesel ran ₱34 → ₱120.46/L through two violent spikes and two collapses. Any straight-line forecast breaks at the next regime shift — the notebook this replaces scored a negative R² on diesel. Meanwhile a home-charged EV held a near-flat ₱1.46–₱2.45/km band and beat diesel every year tested. The one honest caveat: on public DC fast-charging that edge largely disappears.

NCR Diesel Range ₱34 → 120.46 2020 COVID trough → Apr 2026 all-time high (Strait of Hormuz). 2 spikes, 2 collapses.

Meralco Grid Climb +75% ₱8.48 → record ₱14.83/kWh, all-in residential (200 kWh). Steady, not spiky.

EV-Home Saving · Apr'26 spike ₱11,398/mo 1,500 km/mo: diesel ₱15,057 vs EV-home ₱3,659 — 76% cheaper at the peak.

EV-Home vs Diesel /yr 48–69% Cheaper per km in every year 2020–2026. Never once behind diesel.

The diesel regime — and why a straight line can't hold it

NCR pump ₱/L · decimal-year axis

DIESEL_NCR sourced anchor points, 2020.5 → 2026.54

actual regime naïve linear forecast event peak

The dashed line is an ordinary least-squares fit through every anchor point — the same class of model the replaced notebook used. It threads a gentle upward slope straight through both spikes and both collapses, missing every point that matters: it under-predicts Jun 2022 (₱83.5) and Apr 2026 (₱120.46) by tens of pesos and over-predicts the calm troughs. Diesel forecast R² was NEGATIVE — the replaced notebook's linear models scored R² ≈ −17.9 (full history) and −84.6 (recent 6-month), i.e. a fitted line performed far worse than simply guessing the mean. That is the signature of a shock-driven series, not a trend.

Grid climbed steadily · EV/km stayed a low flat band

two views · same six years

MERALCO ₱/kWh all-in residential

grid rate

A different animal from diesel: an orderly +75% ascent — ₱8.48 (Dec 2020 trough) to a record ₱14.83 now. It rises, but it doesn't whipsaw, which is why EV-home cost drifts up gently instead of spiking.

₱ PER KM diesel vs EV-home vs EV-public

diesel EV-home EV-public ₱30

The payoff. Diesel/km swings ₱2.83 → ₱6.83 (₱10.04 at the Apr'26 peak) while EV-home creeps ₱1.46 → ₱2.45 and never crosses the diesel band. EV-public at ₱5.10/km sits far above home charging — the caveat, drawn to scale.

The full per-km ledger

12 km/L · 0.17 kWh/km · 1,500 km/mo

Year	Diesel ₱/L	Grid ₱/kWh	Diesel ₱/km	EV-home ₱/km	EV-pub ₱/km	Save %	Diesel /mo	EV-home /mo	Save /mo

Why the straight line fails — three independently jumpy inputs

PH pump diesel = Brent(USD) × PHP/USD × fixed tax

DRIVER 01

Brent crude shocks

Global oil whipsaws on war, not calendars: $42 (2020) → $100 (2022, Ukraine) → $61 → $118 (Apr 2026, Hormuz) → $72. The pump inherits every jump within weeks.

USD/bbl · 2020→'26$42→$118 peak

DRIVER 02

A structurally weaker peso

Crude is priced in dollars, paid in pesos. PHP/USD went 49.6 (2020) → 57.3 (2024) → 58.4 (2026) — roughly 16% weaker. A flat dollar barrel still costs more pesos at the pump.

PHP per USD+16% weaker

DRIVER 03

Fixed excise + VAT, discretionary relief

Every litre carries a fixed ₱6.00 TRAIN excise + 12% VAT since 2020 — a rigid floor the market can't erode. Then discretionary suspensions (RA 12316) yank the floor without warning, breaking any fitted window.

₱6.00/L excise · 12% VAT+RA 12316 suspension

The honest caveat

CAVEAT

The EV win depends on charging where you sleep.

On public DC fast-charging at ₱30–35/kWh (ACMobility DC ₱35, Tesla ₱19) an EV runs ₱5.10–₱5.95/km — roughly on par with diesel at ₱70/L, and the entire home-charging advantage evaporates. Home charging at the Meralco residential rate is what makes the EV a stable low floor. Fleet economics only hold for operators who can charge overnight at home or depot rates; a public-charge-only duty cycle is a materially different, and much weaker, case.

Methodology, assumptions & sources

EV efficiency: 0.17 kWh/km (17 kWh/100km real-world), charged at the Meralco all-in residential rate.
Diesel ICE: 12 km/L mixed-cycle economy.
Duty cycle: 1,500 km/month for all monthly cost figures.
EV-public: ₱30/kWh mid-band DC (range ₱19–₱35) ⇒ ₱5.10/km reference.
Grid unit: Meralco all-in residential, 200 kWh household, ₱/kWh.
Diesel unit: NCR pump ₱/L. Fixed ₱6.00 TRAIN excise + 12% VAT since 2020.
Linear fit: OLS through all DIESEL_NCR anchors, computed in-page; the model that yields the failing dashed line.
EV excise: EVIDA (RA 11697) sets 0% excise on pure EVs — BYD PH 2026: Seagull ₱898k → Seal ₱2.548M.

Sourced & cross-checked

DOE / CEICMeralco advisoriesEIABSPGlobalPetrolPrices

Anchors were adversarially cross-checked across sources. The event anchors are high-confidence and match the record exactly — Meralco Jul'26 ₱14.8261, Jan'25 ₱11.7428, and diesel Apr'26 ₱120.46 all reconcile to source. The 2020–2024 diesel annuals are approximations shown plainly as such. Single-station diesel touched ₱153.70/L on 2026-04-13; the ₱120.46 NCR figure is the pump-average anchor used here.

The replaced notebook's underlying data was real and accurate — only its forecasting layer (a 75/25 random split on a 19-month time series with unbounded linear extrapolation) was broken, producing the negative diesel R².