The fifth-generation RX replaced the V6-powered 450h with a more efficient 2.5-litre four-cylinder hybrid producing 245 hp combined. Built on the GA-K platform shared with the Toyota Highlander Hybrid, it uses the same A25A-FXS engine and eCVT found across Toyota and Lexus's current hybrid range. The switch from V6 to four-cylinder drew mixed reactions, but real-world fuel economy improved significantly and the hybrid system is one of the most proven in the industry.
Proven A25A hybrid powertrain
Lexus Relax warranty up to 10 years
EGR cooler can crack and leak coolant
Interior rattles and trim fitment issues
Buy if: You want a refined hybrid luxury SUV with low running costs and can verify all recall completions before purchase.
Avoid if: You need a quiet, rattle-free cabin or are sensitive to engine noise under hard acceleration, as the four-cylinder is vocal at full throttle.
Expected Annual Maintenance Costs
Common Problems
Internal heat exchanger in the EGR cooler can crack, leaking coolant into the intake or combustion chamber · more· less
The A25A-FXS engine uses an exhaust gas recirculation cooler that has a known weakness in its internal heat exchanger. The cooler can develop cracks that allow engine coolant to seep into the EGR system and potentially into the combustion chamber. Symptoms include a gradual drop in coolant level, white exhaust smoke, and sometimes a sweet smell from the engine bay. This issue affects all A25A-powered Toyota and Lexus models and is documented in TSBs. The fault can appear at any mileage, though most reports cluster around 40,000-80,000 km. Repair involves replacing the EGR cooler assembly, which costs approximately €800-1,200 at an independent specialist or up to €1,800 at a Lexus dealer. If caught early, there is no lasting engine damage. However, driving with a significant coolant leak into the combustion chamber risks head gasket and catalytic converter damage.
Battery drains within 1-2 weeks if car sits unused, preventing the hybrid system from starting · more· less
Like its predecessor, the RX 350h draws a constant 40-80 mA from the 12V battery due to keyless entry, alarm, telematics, and other always-on modules. If the car sits for 10-14 days without being driven, the 12V battery can be completely flat and the hybrid system will not start. Multiple owners on ClubLexus and LexusRXOwners forums report needing battery replacements within 2-3 years, with some having the battery replaced multiple times under warranty. Lexus has issued software updates that help reduce parasitic drain on some cars, but the fundamental draw remains. A trickle charger (CTEK MXS 5.0 recommended, approximately €80) is considered essential for owners who do not drive daily. Replacement 12V battery costs €150-250 fitted.
Rotational clicking from one or both front CV axle assemblies when accelerating while turning · more· less
Lexus has issued TSB 0033-24 addressing a clicking noise from the front drive shaft assemblies. The noise is most noticeable when accelerating from a stop while turning at low speeds, and is often more pronounced on cold starts. The fix involves replacing the front CV axle assemblies. Some owners report the noise returning after replacement, suggesting the issue may be related to the design of the joint rather than individual component failure. At a Lexus dealer, replacement of both front CV axles costs approximately €800-1,200 including labor. An independent specialist may charge €400-700. This is primarily a comfort issue rather than a safety concern, as the CV joints themselves are not structurally compromised.
Instrument panel garnish trim loosens or detaches, addressed by TSB with improved clips · more· less
Lexus issued TSB L-SB-0018-24 for the instrument panel garnish trim above the glove box becoming loose or detaching. This affects 2023-2024 models and is more prevalent in warmer climates or on rough road surfaces. The fix involves installing improved retaining clips. If the car is still under warranty or within the Lexus Relax programme, this repair is covered at no cost. Outside warranty, the repair is straightforward (approximately €50-200 for clips and labor) but the problem can recur if only the original clips are refitted. This is a cosmetic and quality-of-perception issue rather than a functional problem.
Touchscreen occasionally goes blank for 10-15 seconds or reboots to startup screen while driving · more· less
The new Lexus Interface multimedia system introduced with the fifth-generation RX can experience intermittent screen blackouts and reboots. Owners report the screen going dark for 10-15 seconds before returning, or the system resetting to the boot screen mid-drive. Lexus has addressed some of these occurrences through over-the-air software updates and dealer-flashed firmware. In most cases, a software update resolves the issue at no cost during a regular service visit. In rare cases where the display unit itself is faulty, replacement costs €500-800 at a dealer. The issue appears to have improved significantly on 2024 and later production cars.
High-pitched noise from the front HVAC blower motor when heating or cooling is active · more· less
Lexus TSB L-SB-0039-24 covers a high-pitched whining noise from the front HVAC blower motor on 2023-2024 RX models. The noise is most noticeable at lower fan speeds and can be irritating in the otherwise quiet cabin. The TSB remedy involves fitting a heater cover to dampen the noise. If the blower motor itself needs replacement, the part and labor typically costs €200-400. This does not affect climate control performance and is purely a comfort issue.
Highly reliable with mostly minor early-production niggles
The RX 350h benefits from Toyota's decades of hybrid development, and the A25A-FXS powertrain is shared with hundreds of thousands of RAV4, Highlander, and Camry hybrids worldwide. The EGR cooler is the only mechanical concern worth monitoring. Most other issues are related to cabin trim, software, and 12V battery drain, which are annoying rather than costly. Build quality improved noticeably after the 2022 launch year. The Lexus Relax programme, which extends warranty coverage to 10 years with annual dealer servicing, provides exceptional peace of mind for this model.
Recalls and Technical Service Bulletins
Spiral cable assembly (driver airbag may not deploy, Feb-Jun 2023 production)
Critical - verify completed
Head restraint lock release failure (2024 models, front seats)
Verify completed
Second-row seat belt webbing damage (2024-2025 models)
Verify completed
Instrument panel software error (speed/warning display failure, 2025 models)
Verify if applicable
Contact Lexus with the VIN to verify all recalls have been completed. The spiral cable recall is particularly important as it affects driver airbag deployment. Early 2023 production cars are most likely to have outstanding recalls.
Warranty Status
Factory warranty (3 years / 100,000 km)
Active on 2023+ models depending on registration date
Lexus Relax extended warranty
Up to 10 years with annual dealer servicing
Hybrid battery warranty
8 years / 160,000 km standard, extendable with Lexus Relax
Lexus Relax is one of the most comprehensive warranty programmes available. It extends coverage to 10 years from first registration as long as the car is serviced annually at an authorised Lexus dealer. This is particularly valuable for hybrid components. Verify whether the previous owner maintained the Relax programme before purchasing.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.