One trip. Two directions.
What changes if you drive slower—or faster—than planned?
Set the speed you planned, choose what matters, and explore 10–180 km/h. Time uses exact ideal-speed math; fuel becomes a clearly flagged estimate outside the road-test band.
The answer
Drive 20 km/h slower
Exploring the trade-off: no universal “best” speed is selected; time and fuel are shown side by side.
You save €4.55 and use 2.60 L less fuel, while the trip takes 36 minutes longer.
Worth of the trade-off: €7.51 saved for every extra hour on the road.
90 km/h is a measured road-test point.
Use only legal and safe speeds. Traffic, stops, weather, wind, elevation, payload, tyres, HVAC and hybrid battery state can change real results.
Optimize for a time or fuel goalOptional
Set a clear minimum or maximum
Each goal is a threshold, not an approximate target. “At least” finds the smallest speed change that reaches your minimum. “At most” finds the fastest option that stays within your fuel-cost ceiling.
The solver searches 10–180 km/h. Time math remains exact for ideal steady speed; any fuel result outside 90–140 km/h is marked as an estimate.
Goal rule: Save at least 20 min. The solver uses the smallest speed increase that meets this minimum.
Goal met · minimum reached
125.5 km/h Saves at least 20 min, with the smallest speed increase that reaches the goal.Why it changes
Speed buys less time as it rises—and fuel use has a broad efficient middle.
Trip time
Every +20 km/h saves a smaller share
10 → 30: 67% shorter
100 → 120: 17% shorter
Because time = distance ÷ speed. Tripling speed cuts time to one third; adding 20 km/h at motorway speed is a much smaller proportional change.
Swipe graph sideways ↔
Fuel consumption
Low-speed overhead → efficient middle → aerodynamic rise
The measured Corolla anchors define the solid middle. The dashed outer curve lets you explore extremes without presenting estimates as measurements.
Swipe graph sideways ↔
Fuel estimate90–140 measured + interpolatedFuel estimate
Fuel is estimated outside 90–140 km/h. The calculator uses this broad physics-shaped curve when you explore those speeds; it is not measured Corolla behaviour.
Data, method and limitationsSources
What the calculator uses
2022 Toyota Corolla Touring Sports 1.8 Hybrid, 122 hp, e-CVT, FWD.
Measured road-test anchors: 90 km/h → 4.3 L/100 km; 120 → 5.6; 140 → 7.3. Values between anchors use straight-line interpolation. From 10–90 and 140–180 km/h, trip time still uses distance ÷ speed, while fuel uses the dashed illustrative curve and is labelled as an estimate.