The comparison, published in The Wall Street Journal, also said the Tesla Model 3 came out ahead in the total cost of ownership at between US$49,800 (A$65,644) and US$51,000 (A$67,226). No TCO was given for the RAV4.
The study looked at greenhouse gas generation right from the time the two vehicles were made.
The vehicles were chosen as they were "two popular cars that are best-sellers in their categories: a mid-size sedan that runs on electricity and a more lightweight compact SUV that uses gasoline", the WSJ's Russell Gold, Jessica Kuronen and Elbert Wang wrote.
The study said the RAV4 not only used petrol to run, but also needed an oil change after 5000 miles; though the Tesla ran on electricity, it did generate some emissions as creating the electricity resulted in emissions.
This depended on the type of electricity coming into the grid "...but the US grid is getting cleaner each year, burning less coal and using more renewables and natural gas," the authors noted.
After running 20,600 miles, the Tesla was found to have emitted 34% of the emissions that came from manufacturing and burning the petrol consumed by the RAV4.
"At 20,600 miles, the greenhouse gas emissions from building and driving the two cars are roughly the same, according to the University of Toronto analysis. Then the Tesla pulls ahead," the report said.
The authors noted that the emissions would be influenced by the place where the Tesla was charged. "The abundance of hydropower in the Pacific Northwest makes the electricity there cleaner. We used a national average for our calculations," they said.
The study also looked at the environmental impact of the entire US fleet of light-duty vehicles, roughly more than 280 million, and about 17% of the total American vehicles, depending on the mix of electric and petrol vehicles.