Most underrated engines

It may seem odd that car manufacturers would "shortsell" their cars by advertising lesser peak power than engines can actually deliver. However, there are several potential reasons for such discrepancy.

No two examples of same engine are 100% identical - some leave factory slightly more or less powerful than advertised. This can account for few percentage point drift against manufacturer numbers, however, there are cases when underrating and overperformance is significant and systemic.

One possible reason is taxation based on engine power or emissions that is applied in some countires. Another could be insurance cost - some insurers charge more based on power thresholds.

Less common but most amusing is underrating for marketing reasons - yes, you read that correctly - some manufacturers are suspected to report lower engine power to make their cars seem more sophisticated in other areas (chassis, handling), when compared to competitors with higher advertised power output.

Sometimes manufacturers are also alleged to alter boost maps for cars that are delivered to automotive press, unfairly improving performance in instrumented tests.

Sources

All data sourced from manufacturer's official figures.

List authored by SupercarLists.com. Last updated on 03/06/2026, last addition - Nissan Tiida 1.5 dCi.