What is the fuel consumption of the RX400h hybrid?
The RX 400h hybrid typically achieves in the mid-20s miles per gallon (mpg) in mixed driving, with real-world results depending on year, drivetrain, and driving style.
In this article, we examine official EPA estimates for the RX 400h, how those figures varied across model years, and what drivers can reasonably expect in city and highway conditions today. We’ll also place the RX 400h in the broader context of Lexus’ hybrid lineup and note how later models improved efficiency.
Overview of fuel-economy figures
The RX 400h was Lexus’ early foray into a gasoline-electric SUV. Its EPA ratings depend on the drivetrain (front-wheel drive vs all-wheel drive) and model year. Below are representative EPA ranges for typical U.S. models during its production years.
EPA estimates for the RX 400h generally fall into the following ranges, reflecting city, highway, and combined figures across production years.
- Combined fuel economy: typically about 25–27 mpg (roughly 9.5–10.5 L/100 km), depending on year and drivetrain.
- City driving: commonly in the low- to mid-20s mpg (roughly 23–25 mpg).
- Highway driving: commonly in the high-20s to low-30s mpg (roughly 27–30 mpg).
These figures come from EPA estimates published during the RX 400h’s production window (roughly 2006–2009 for model years 2006–2009). Real-world results can vary with tires, climate, load, and driving style.
Model-year notes and drivetrain differences
Drivetrain differences
During its production run, the RX 400h offered front-wheel drive (FWD) or all-wheel drive (AWD). While the AWD system adds weight and can slightly adjust efficiency, the hybrid powertrain generally yielded similar overall economy across layouts. In most model-year cycles, the combined mpg hovered in the mid-20s, with city mpg typically in the low- to mid-20s and highway mpg in the upper-20s to around 30 mpg depending on conditions.
Context: the RX 400h was eventually superseded by newer Lexus hybrids, notably the RX 450h, which introduced revised powertrains and higher efficiency.
Real-world factors that affect fuel economy
As with any hybrid, several factors influence actual mpg beyond the EPA numbers—driving style (gentle acceleration and steady speeds), climate control use, tire type and pressure, payload, and battery state of charge all play a role. Short trips and cold weather can reduce hybrid efficiency, while highway cruising at steady speeds tends to yield better mileage.
In the years since the RX 400h, Lexus improved hybrid efficiency with subsequent models, offering higher mpg in the RX lineup and other hybrids.
Summary
The RX 400h’s fuel economy sits in the mid-20s mpg in typical mixed driving, with city figures in the low-20s and highway figures in the high-20s to around 30 mpg. Real-world results vary by year, drivetrain, and driving conditions. For buyers and owners of this classic hybrid, expect moderate fuel savings relative to traditional gasoline V6 SUVs of its era, with better mileage achievable on longer highway trips under light-load conditions.
Notes on the RX 400h’s place in the Lexus hybrid timeline
Produced roughly from 2005 through 2009 (model years 2006–2009 in North America), the RX 400h was Lexus’ first mainstream hybrid SUV. It set the stage for subsequent models like the RX 450h, which offered improved efficiency and newer hybrid technology while retaining the luxury and versatility the RX lineup is known for.
