An independent range test run on the same road, on the same day, at the same speed has found Rivian‘s R2 Performance covering 76.7% of its EPA-rated range while a Tesla Model Y Performance exceeded its own.
The R2 travelled a corrected 253 miles against a 330-mile rating. The Model Y covered 317.8 miles against 306 miles, finishing 3.9% beyond the figure on its window sticker.
Measured as a proportion of each car’s own rating, the two vehicles are 27 percentage points apart.
Out of Spec Reviews founder Kyle Conner, who ran the test alongside RivianTrackr‘s Jose Castillo, placed the responsibility on the certification system rather than on either manufacturer, arguing the two EVs had been rated under different cycles and that the discrepancy is “a problem with the rating system.”
How the Test Was Run
Both vehicles ran simultaneously on Interstate 64 in North Carolina at a GPS-verified constant 70 mph, from a full charge until each could no longer hold that speed.
Conditions were unusually favourable in one respect and demanding in another. The route is tree-lined for its length, eliminating crosswind, and wind was light. Ambient temperature was 98 degrees Fahrenheit, imposing a substantial air-conditioning load on both cars.
Tyre pressures were set to 42 psi cold on both vehicles.
The R2 ran in Conserve mode with Universal Hands-Free engaged; the Model Y ran in Chill mode driven manually, because its lane centring is only available through Full Self-Driving, which does not permit a set speed.
A Porsche Cayenne ran the same route as a reference vehicle, and its odometer was used as ground truth to correct the other cars’ distance readings. Both the R2 and the Model Y over-reported distance, the R2 by roughly two miles.
A Rivian R1S Dual-Motor with the Max pack also ran the route. That result was not published with these figures.
The Configuration Was Supplied by Rivian
Castillo took delivery of his R2 on 20-inch all-terrain tyres. The car was tested on 21-inch road wheels with Pirelli Scorpion MS tyres in a square 255/55 R21 setup.
Conner said Rivian provided those wheels and tyres for the test, and that he wanted to benchmark the most efficient configuration available because the first published figures tend to be the ones referenced afterwards.
The 330-mile EPA rating applies to that configuration. The all-terrain setup Castillo owns is rated at 307 miles.
What the R2 Did
The R2 logged 255 miles on its own display, corrected to 253 against the reference vehicle.
Energy consumed reached 89.3 kWh, more than the 87.9 kWh Rivian quotes as usable capacity.
Conner noted that vehicles frequently deliver more than manufacturers state, and that the readings come from the car’s own sensors rather than external measurement.
Corrected efficiency worked out at 2.83 miles per kWh, against 2.88 on the in-car computer.
Two behaviours stood out during the run.
In Conserve mode the vehicle displayed 334 miles at full charge, four miles above the EPA figure — a difference Conner noted would widen the gap further if Rivian had certified in that mode.
And indicated range fell sharply once the battery dropped into single digits, with Castillo reporting the numbers dropping away quickly at low state of charge.
The car held 70 mph past zero indicated range before turtle mode ended the run.
What the Model Y Did
The Model Y consumed 82.2 kWh over 317.8 miles at 258.5 Wh per mile, or 3.87 miles per kWh.
The car reached zero indicated charge at roughly 300 miles and continued for a further 18 before shutting down.
Conner described the ending as atypical for the brand: rather than progressively limiting power until the speed could no longer be held, the vehicle cut out while still maintaining 70 mph.
The pack is a new Panasonic 2170 cell built at a plant in Kansas, with thinner cell walls and roughly 5% more capacity than the Long Range pack. Tesla quotes 84 kWh gross and 81.4 kWh usable.
One procedural detail worked against the Tesla. The driver-only climate setting used in earlier tests has been removed from the car, so passenger-side air conditioning ran throughout.
The Argument About the Ratings
Conner’s conclusion was directed at the Environmental Protection Agency (EPA) rather than at either company.
He said the two vehicles appear to have been certified under different test cycles, making the headline numbers non-comparable, and that manufacturers can select between those cycles.
On his reading, Rivian optimised for the highest advertised range while Tesla certified in a way that tracked real-world performance more closely.
He described the outcome as a rating-system failure rather than a manufacturer one, and noted that cars falling short of EPA figures in cold or windy conditions is routine, whereas a 23% shortfall on a warm, still day is not.
Measured against the EPA highway rating rather than the combined figure — 301 miles for this configuration — the R2’s result comes to 84.1%. The 330-mile number is the one that appears in marketing and on the sticker.
Context
Out of Spec published a separate efficiency comparison of the same two vehicles earlier this week, finding the R2 consuming between 18.4% and 26.5% more energy than the Model Y at every speed measured.
On paper the two carry identical combined ratings of 105 MPGe, with the R2 rated for 24 miles more range on equivalent consumption. Founder and chief executive RJ Scaringe has said the R2 matches Model Y efficiency.
Needham this month called the R2 the first legitimate competition the Model Y has faced.
Rivian reports second-quarter results on Thursday, July 30, after market close.
