Road Trip Fuel Cost & Stop Planner

Road Trip Fuel Planning Guide

Real-World vs Official Fuel Economy

Official WLTP fuel economy figures consistently overstate real-world performance by 10-25%. A car rated at 60 mpg typically delivers 45-50 mpg in mixed real-world driving. Motorway driving at 70 mph is less efficient than the WLTP test cycle (which assumes varied speeds). Add 15-20% to official consumption figures for realistic planning, especially for long motorway journeys. Factors increasing consumption: high speed (aerodynamic drag increases with speed squared — 80 mph uses approximately 25%

Fuel Stop Planning

Do not let the fuel level drop below one quarter of the tank on a long journey — fuel pumps in fuel-injected cars sit in the fuel tank and are cooled by the fuel. Running near empty can overheat and damage the pump. For motorway journeys: fill up before joining the motorway — motorway service station fuel is typically 8-15p/litre more expensive than supermarket forecourts. Apps like Waze and GasBuddy show current fuel prices at stations near your route. For electric vehicles: plan charging stops

Petrol vs Diesel vs Electric Running Costs

Real-world running cost comparison per 100 miles (UK 2024): petrol car averaging 40 mpg at 154p/L: approximately £17.50. Diesel car averaging 50 mpg at 161p/L: approximately £14.60. Hybrid averaging 55 mpg: approximately £13.30. Electric car at 3.5 miles/kWh on home tariff (24p/kWh): approximately £6.80. Electric at public rapid chargers (75-85p/kWh): approximately £21-24. The EV advantage evaporates entirely when using public rapid chargers — home charging is where EV economics work. For long t

Total Trip Budget Beyond Fuel

Fuel is typically 30-50% of total road trip cost. Other major costs: accommodation (typically the largest single cost on multi-day trips). Tolls: France A-roads are tolled (budget £50-80 per 1,000km). Spain and Portugal also have tolls. UK has no motorway tolls except the M6 Toll. Food and drink: plan snacks and a flask to avoid service station food markups (2-3× supermarket prices). Parking: city centre parking in Europe £5-25/day. Travel insurance. Breakdown cover. EHIC/GHIC for European healt