If you disqualify hybrids and allow diesels... https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform&path=1&year1=1984&year2=2020&make=Toyota&baseModel=

If you disqualify hybrids and allow diesels... https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform&path=1&year1=1984&year2=2020&make=Toyota&baseModel=Corolla&srchtyp=ymm https://www.fueleconomy.gov/feg/PowerSearch.do?action=noform... But the weight difference is also substantial between 1984 and 2020 models: 2110 lbs vs 2910 lbs