Although Lexus calls this a Luxury Sport Utility Vehicle (SUV), the RX400h is built on a unibody, not a full frame, so technically it’s a crossover with very limited Utility. Still, it is definitely a Luxury vehicle, and with a total of 268 horsepower and a curb weight of 4400 pounds, acceleration is quite acceptable if not exactly Sporting.
In theory this is a 4X4, but since the driver cannot select four-wheel-drive, it’s only available for the vehicle’s stability control system (VDIC). Up front is Toyota’s standard hybrid powertrain with a (V6) gasoline engine, two electric motor/generators and a special planetary gear set that acts as a continuously variable transmission. A third electric motor on the rear axle adds power only if the front wheels are slipping. However, if the vehicle stops with all four wheels on a slippery surface, it’s extremely difficult to get moving again because the computer won’t provide power to the wheels if they’re slipping.
Aside from this, most owners like the RX400h and have reported few other issues. Gas mileage has been less than expected but still better than other non-hybrid SUVs. Being a Lexus, reliability is near the top of the heap, but like any other vehicle loaded with luxury features, some features tend to fail as the vehicle ages.
Service can be expensive at a Lexus dealership, and any shop that advertises hybrid service should have no trouble with this vehicle. Still, there are some Recalls and Factory Service Bulletins that really should be addressed by the dealer. Among them is a (free) Safety Recall to replace the Intelligent Power Module that controls the hybrid powertrain. Also, most vehicles eventually suffer a water leak at the rear hatch that can cause problems with the battery pack. The large battery under the rear seat has three cooling fans, a bank of relays and an electronic control unit. A Service Bulletin notes that spilling liquid in the back seat has been known to damage these components, and that damage is not covered under warranty.
A Lexus dealer will address these issues before selling a used RX400h, so if you’re buying from a private owner, ask to see the vehicle’s service records.To find a hybrid vehicle service shop near you, go to shop finder on this web site.