Real-World Test Shows R2 Efficiency Significantly Trails Model Y
Independent testing organization Out of Spec Reviews recently published results comparing the real-world energy efficiency of the Rivian R2 Performance and Tesla Model Y Performance. Conducted on the same route, the test covered speeds of 50, 60, 70, and 80 mph, revealing that the R2 consumed 18% to 26% more energy than the Model Y at every tested speed. This finding starkly contrasts with the U.S. Environmental Protection Agency’s (EPA) official data, which certifies both vehicles with identical combined efficiency ratings of 105 MPGe and an energy consumption of 32 kWh per 100 miles.
Kyle Conner, founder of the testing team, stated that variables were strictly controlled before the test. Both vehicles’ batteries were allowed to reach ambient temperature, tire pressures were uniformly set to 42 PSI (cold), cabin temperatures were maintained at 68°F, and rear seat vents were closed. Each vehicle carried two passengers, infotainment screens were dimmed, and phone charging was disabled. The R2 was set to “Conserve” mode, while the Model Y was in “Chill” mode. The test route used a bidirectional loop, with the vehicles alternating the lead position to mitigate wind resistance effects. Energy consumption was measured at the battery level rather than relying on the vehicles’ displayed data.
At 80 mph, the R2’s efficiency ranged from 2.2 to 2.5 miles per kWh, while the Model Y achieved 3.1 to 3.3 miles per kWh, a gap exceeding 26%. The 70 mph test encountered heavy traffic, with both vehicles affected by drafting behind large trucks, reducing the reliability of the data. In a 20-minute low-speed city driving simulation, the R2 consumed 1.9 kWh compared to the Model Y’s 1.6 kWh, with the R2 using approximately 19% more energy. Despite the R2’s ability to disconnect its front axle motor via a clutch—expected to improve urban efficiency—the real-world results showed no advantage.
Causes of Discrepancy Between EPA Ratings and Real-World Use
EPA efficiency ratings are based on laboratory data, and automakers can choose from different testing procedures. The simplest method involves a single city and highway cycle test, adjusted by a 0.7 correction factor. A more rigorous multi-cycle test includes four city cycles, two highway cycles, and two constant-speed cycles, better reflecting the impact of hot and cold weather as well as high-speed driving. Automakers may also apply for EPA-approved derived five-cycle tests or correction factors based on real-world usage data. Conner suspects Rivian may have subjected the R2 to the full multi-cycle test, while Tesla used derived data, but the EPA does not publicly disclose the testing methods for individual models, leaving this claim unverified.