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Reference table

Fuel Efficiency Improvement Table: Efficiency improvement by Old fuel efficiency

Reference table of efficiency improvement for Fuel Efficiency Improvement across a range of old fuel efficiency values — exact, engine-computed figures you can read off at a glance.

By Arjun Desai, B.Tech (Engineering) · Updated Jun 2026 · 1 min read

This fuel efficiency improvement reference table shows the efficiency improvement for a range of old fuel efficiency values, assuming a new fuel efficiency of 15 km/l. Every figure is computed with the same engine that powers our Fuel Efficiency Improvement Calculator, so the numbers are exact.

Old fuel efficiencyEfficiency improvement
3 km/l400.00%
6 km/l150.00%
9 km/l66.67%
12 km/l25.00%
18 km/l-16.67%
24 km/l-37.50%
36 km/l-58.33%
60 km/l-75.00%
84 km/l-82.14%
120 km/l-87.50%

How to use this table

Find the row closest to your old fuel efficiency and read across to the efficiency improvement. For a value between two rows, the real figure sits between them — or enter your exact numbers in the Fuel Efficiency Improvement Calculator for a precise answer.

Need a value that is not in the table? — the Fuel Efficiency Improvement Calculator does it instantly, for free, with the formula and a worked example built in.

Continue exploring automotive calculators with these tools: Engine Displacement Calculator, Compression Ratio Calculator, Horsepower to Torque Calculator, Gear Ratio Calculator, Tire Size Calculator.

Calculators in this guide

Frequently asked questions

Each cell is computed with the standard formula using exact arithmetic — the same calculation behind our Fuel Efficiency Improvement Calculator — so every figure is accurate for the stated assumptions.

Yes. The table covers common old fuel efficiency values; for any exact figure, enter your own numbers in the Fuel Efficiency Improvement Calculator.

Arjun Desai · B.Tech (Engineering)

Arjun Desai is an engineer who writes about the practical physics, electronics and energy calculations behind everyday technology.