yup, malaki n tlga improvement ng mga diesel engines.

the main reason why old diesel engined vehicles were slow was their weight. their engines used to be made exclusively from iron to tolerate the stronger but slower combustion of diesel. unfortunately they're also a lot heavier than gas engines. tpos yng mga vehicles n gumagamit ng diesel engines noon usually have reinforced bodies kya medyo mabigat cla. (for towing, transport, etc...) kya mabagal cla umarangkada.

diesel fuel also burns a lot slower. dun galing yng pulling power ng diesel engines. the slow burn allows the engine to generate more power per revolution than gas engines.

but if installed in lighter vehicles, they do have the capability to push the vehicles to good speeds. (used to make the wheels of our adventure squeal: just don't tell my dad) the nissan safari is a good example.

newer diesel engines are lighter na. plus diesel fuels these days have improved combustion and burn cleaner. konti n lng and they will combust as well as gasoline na din. allowing diesel engines to rev higher and maybe match the revolutions gas engines are capable of