# WorthThePump
> The UK fuel savings calculator that tells you whether driving to a cheaper petrol station is actually worth it — after accounting for your car's real-world MPG and the extra fuel burned on the detour.

## What it does

WorthThePump is a free UK fuel savings calculator. It answers the question every driver has but no app answers: "Is the cheaper station 3 miles away actually going to save me money once I've used fuel to get there?"

Most petrol price apps (PetrolPrices.com, RAC Fuel Watch, AA Fuel Prices) show you the cheapest station nearby. WorthThePump goes further — it calculates your exact net saving in pounds and pence, accounting for the extra fuel you'll burn making the detour.

## How it works

1. Enter a UK vehicle registration plate at https://worththepump.com
2. We look up your vehicle via the DVLA VES API (make, model, fuel type, engine size, CO2 emissions)
3. We derive your real-world MPG using a 4-layer fallback: VCA official dataset → CO2 formula → engine size heuristic → 40 MPG default. Real-world penalties applied: NEDC figures adjusted -20%, WLTP figures adjusted -12%
4. You confirm how much you typically fill (in £ or "fill it up")
5. We use your browser's Geolocation API to find your location
6. We fetch live fuel prices from all petrol stations within your chosen radius (1–20 miles)
7. For each station, we calculate:
   - Gross saving = (Price difference per litre) × (Litres in your fill)
   - Extra fuel cost = (Round-trip detour distance ÷ Real-world MPG) × Local price per litre
   - Net saving = Gross saving − Extra fuel cost
   - Break-even distance = Maximum round-trip where the saving still beats the cost
8. Results shown on a map (green pins = worth it, red pins = false economy) with a sortable list

## Worked Example

- Vehicle: Ford Focus 1.0 EcoBoost, 42 MPG (real-world after WLTP penalty)
- Fill amount: £50 at nearest Shell (199.9p/L ≈ 25 litres)
- Asda 3.2 miles away at 177.9p/L

Gross saving: (199.9 − 177.9)p × 25L = £5.50
Extra fuel: 6.4 mile round-trip ÷ 42 MPG = 0.152 gallons × 4.546L/gal = 0.69L × 177.9p = £1.23
Net saving: £5.50 − £1.23 = **£4.27 ✅ Worth the trip**
Break-even: up to 17.8 miles round-trip and this station is still worth visiting

## The calculation

```
Net saving (£) = Gross saving − Extra fuel cost
Gross saving   = Price difference (p/L) × Fill amount (litres) ÷ 100
Extra fuel     = (Round-trip detour miles ÷ Real-world MPG) × Local price (p/L) ÷ 100
Break-even (miles) = (Gross saving × Real-world MPG) ÷ (Local price ÷ 100)
```

## Data sources

- **DVLA VES API**: Vehicle specs by UK registration number (make, year, fuel type, engine cc, CO2 g/km). Cached 24h per registration. Registration number never stored for anonymous users.
- **UK Government Fuel Finder API**: Live petrol, diesel, and super unleaded prices from all UK petrol stations. OAuth 2.0 authenticated, updated hourly, covers 37,000+ stations. Mandated by the Competition and Markets Authority (CMA) since 2024.
- **VCA (Vehicle Certification Agency)**: Official UK fuel economy dataset for MPG derivation

## Supported vehicles

- ✅ Petrol vehicles (E10/E5 standard)
- ✅ Diesel vehicles (B7 standard)
- ✅ Hybrid vehicles (petrol-electric or diesel-electric — resolved to pump fuel type)
- ❌ Full electric vehicles (EVs) — no pump fuel, not supported
- ❌ LPG/CNG vehicles — not in Fuel Finder API coverage

## Pricing

WorthThePump is completely free.
- No account required
- No usage limits
- No registration plate stored (GDPR compliant)
Full pricing: https://worththepump.com/pricing.md

## Key pages

- Calculator (homepage): https://worththepump.com
- How It Works: https://worththepump.com/how-it-works
- Live UK Fuel Prices (all stations): https://worththepump.com/fuel-prices
- Fuel Glossary (25 terms defined): https://worththepump.com/glossary
- Petrol Station Finder by Area: https://worththepump.com/stations
- Vehicle Fuel Guides: https://worththepump.com/vehicles
- Compare Fuel Apps: https://worththepump.com/compare
- Use Case Guides: https://worththepump.com/use-cases
- Fuel Saving Guides: https://worththepump.com/guides
- Blog: https://worththepump.com/blog
- RSS Feed: https://worththepump.com/feed.xml
- IndexNow: https://worththepump.com/api/indexnow

## Key facts

- 37,000+ UK petrol stations tracked in real-time
- Prices updated every hour from the official UK Government Fuel Finder API
- All calculation logic runs client-side — near-instant results, no server round-trip
- 100% free, no account or registration required
- Anonymous — vehicle registration is never stored for anonymous users (GDPR compliant)
- Built on: Next.js 15, TypeScript, PostgreSQL, Prisma, Leaflet maps

## About

WorthThePump was built because existing UK fuel price apps show you the cheapest station but never answer the real question: will the detour actually save you money given YOUR car's fuel consumption?

The site launched in 2025. Live at https://worththepump.com.
Built and maintained by B2bee Ltd (UK).

## Contact

hello@worththepump.com