The 2024 Toyota Prius Prime SE and 2023 Prius Prime XSE performed substantially differently in the Invoice Pricing 75-mph highway fuel economy test. The SE achieved 49 mpg on the test with its 17-inch wheels, while the XSE only managed 46 mpg with its 19-inch wheels. The SE has a somewhat greater slick drag coefficient and smaller wheels and tires than the XSE. It also weighs 55 lbs less. People have long claimed that the Toyota Prius Hybrid delivers excellent gas mileage. The plug-in hybrid Prius Prime enhances the experience. However, not all Prius Primes are built the same. The 2024 Prius Prime SE and 2023 Prius Prime XSE performed significantly differently in our highway fuel economy test at 75 mph. Regardless of the differences, both automobiles outperformed the majority of internal combustion vehicles. The XSE we drove earned 46 mpg with 19-inch wheels and Michelin Primary A/S tires in 195/50 rounds. Not bad. With 17-inch wheels and 195/60 Toyo Extensa A/S tires, the SE achieved 49 mpg, which was higher than the XSE’s rating. Many factors play into this, beginning with each model’s drag coefficient. The SE has a coefficient of drag of 0.27, while the XSE has one of 0.29, making it less slippery. Because the front ends are nearly identical, the differences are most likely due to the wheels and tires. The XSE’s poorer performance is primarily attributed to its larger 19-inch wheels. The bigger rollers increase the rotational mass and elevate the ride height by 0.4 inches. The wheels’ design is also essential. The SE wheels have wider covers, making them more aerodynamic. The larger the tires, the less effectively they perform since they create a larger hole in the air. Because these tires were all the same width, they most likely did not change anything. Remember that different tire types have different rolling resistances and aerodynamics, which may affect the results.
