Regarding the latter, the efficiency of petroleum-based engines in cars has improved considerably, particularly in periods of high oil prices such as 1975-1987 and the last few years.
Hinggil sa huli, ang kahusayan ng petrolyo-based na engine sa mga kotse na bumuti masyado, lalo na sa mga panahon ng mataas na presyo ng langis tulad ng 1975-1987 at ang huling ilang taon.