Estimate total fuel cost for a multi-stop road trip.
Total fuel cost = (total distance ÷ mileage) × fuel price. Per-person cost splits this evenly.
A long highway drive feels like the efficient way to cover distance, and it usually is — but the speed you maintain on that highway matters more to your fuel budget than most road-trippers expect. Aerodynamic drag increases with the square of speed, not linearly, so sustained driving at 110 km/h instead of 80 km/h can cut fuel efficiency by 8-12%, purely from the extra force needed to push through the air at higher speed. On a long trip, that gap compounds: shaving 30 minutes off a journey by driving faster can genuinely cost more in fuel than the time saved is worth, especially once you also factor in that most fuel-efficiency certifications (like ARAI) never even test beyond 90 km/h, so there's no official figure covering typical highway cruising speeds at all.
Trip cost planning benefits from breaking the drive into its real conditions rather than applying one blanket mileage figure: highway stretches at consistent speed are typically your most efficient driving, city sections with stop-go traffic and idling are meaningfully less efficient, and any hill or mountain driving adds further load. Vehicle load matters too on a road trip specifically, since trips often mean a fully loaded car with luggage and passengers — roughly 1-2% mileage loss per extra 50kg carried, which adds up when a car that's normally driven with one person is suddenly carrying four adults plus bags. For a genuinely accurate trip cost estimate, it's worth using a mileage figure on the lower end of your normal range (closer to your city-driving number than your best-case highway number) rather than assuming best-case efficiency for the entire route.
Yes, more than most people expect — aerodynamic drag rises with the square of speed, so sustained driving at 110 km/h instead of 80 km/h can cut fuel efficiency by 8-12%. Over a long road trip, that difference in fuel cost can outweigh the value of the time saved by driving faster.
Neither alone is ideal — a realistic road trip usually mixes highway cruising (most efficient), city or town sections with stop-go traffic (less efficient), and possibly hill driving (least efficient). For a conservative, more accurate estimate, lean toward a mileage figure closer to your city driving number rather than assuming best-case highway efficiency applies to the whole trip.
Roughly 1-2% mileage loss for every extra 50kg carried. This matters specifically for road trips, where a car normally driven with one person suddenly carries multiple passengers plus luggage, meaningfully increasing the vehicle's effective weight compared to everyday driving.
Because ARAI's official test cycle never tests fuel efficiency beyond 90 km/h, while typical Indian highway cruising speeds often exceed that. This means there's no official certified figure covering the exact conditions most road trips actually involve — which is part of why real-world road trip mileage often differs noticeably from the number on the car's brochure.