Toyota and Lexus aren’t well-known for being leaders in EVs. There is just one all-electric car available from each company, and neither model has very impressive range or charging capabilities. However, our audience was taken aback by how well the RZ 300e performed when Lexus released its efficiency statistics. We enquired of Lexus how the entry-level RZ stealthily rose to the top of the list of EVs available for purchase.
I don’t blame you if you’re not familiar with the RZ series; the base model 300e debuted in 2024. The FWD RZ 450e is significantly more efficient than the AWD model, which Lexus was already marketing.
With charging losses taken into account, the standard model’s mileage per kWh is 125 MPGe, or around 3.7 miles. Compared to a Tesla Model Y, that is more efficient. It’s among the most efficient EVs overall and the most efficient EV SUV currently for sale.
Only a small number of electric vehicles from the 2024 model year performed better. Out of seven different car models, three are more efficient: the Tesla Model 3, the Hyundai Ioniq 6, and the Lucid Air.
The question of how the Lexus RZ 300e became so efficient is fascinating because the original 450e version is far behind at 107 MPGe (315 Wh/mi or 3.2 miles/kWh). Plus the Lexus is far more efficient than the Toyota bZ4x on which it is based, which gets 119 MPGe in the EPA cycle. That’s an inversion of what we typically expect: Luxury vehicles are heavier, and therefore usually less efficient than their mainstream counterparts.
Lexus spokesperson Laura Finley confirmed 125 MPGe as the correct rating. As it turns out, there are several reasons why the 2024 Lexus RZ 300e uses less energy than the 450e.
First of all, this version has a single-motor, front-wheel drive powertrain making 201 horsepower, compared to the dual-motor, all-wheel-drive 450e that produces 308 hp. This one change removes some weight and reduces the axle friction from the rear e-axle. The RZ 300e’s base curb weight is 4,277 lb, while the RZ 450e weighs in at 4,564 lb.
Another efficiency boost comes from the front e-axle inverter. In the RZ 450e, the inverter semiconductor is made out of silicon (Si). In the RZ 300e, Lexus uses a silicon carbide (SiC) semiconductor, which is more efficient. I’d guess this change improves efficiency by a few percent. It’ll be interesting to see whether Lexus brings the SiC-type semiconductor to the AWD version in the next update.
For now, the SiC is unique for the RZ 300e. It’s not used in the FWD version of the Toyota bZ4X, which may explain that model’s lower efficiency rating.
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