Diesel
A combustion engine that ignites diesel fuel by compression. CarPairly lists it apart from gasoline ICE because fuel price, consumption and taxation can differ.
A diesel engine is a combustion engine that ignites fuel by compressing it rather than with spark plugs. According to fueleconomy.gov, diesel engines are more fuel-efficient and have more low-end torque than similar-sized gasoline engines. The same page names particulates and smog-forming nitrogen oxides (NOx) as the emissions of concern from diesels.
Rules for diesel cars differ by place. Some UK Clean Air Zones, for example, charge cars by Euro emissions standard, and Euro 6 is the diesel standard that avoids the charge. Check local rules if you drive into cities often.
CarPairly treats Diesel as its own powertrain within the Gas branch, separate from gasoline ICE, because its fuel price, consumption profile, and taxation can differ. When comparing, look at fuel consumption in L/100 km or mpg together with local diesel prices, not gasoline prices.
Differs by market
As of September 2026: ACEA reports diesel cars were 8.9% of new car registrations in the EU in 2025. Some UK Clean Air Zones charge cars that do not meet Euro 6 (diesel) or Euro 4 (gasoline) standards, so check local rules.