UGA team develops method for genetic engineering of Caldicellulosiruptor thermophilic bacteria; another pathway for efficient conversion of biomass to fuels and chemicals
Alberta approves Lower Athabasca Regional Plan

2013 GS 450h EPA-rated at 31 mpg combined; 35% improvement over preceding generation

2013 Lexus GS 450h. Click to enlarge.

Lexus’s 2013 GS 450h—the new generation hybrid version of the GS 350, introduced at the 2011 Frankfurt Motor Show (earlier post)—offers EPA-estimated fuel economy ratings of 29 mpg US city, 34 mpg US highway and 31 mpg US combined (7.7, 6.9 and 7.6 L/100km, respectively).

These figures represent a 32%, 36% and 35% improvement in fuel economy, respectively, compared to the prior generation of the GS 450h (e.g., MY 2011). These figures also represent a 53%, 21% and 35% improvement in fuel economy, respectively, compared with the conventional 2013 GS 350. (As a side note, the combined cycle fuel economy of the conventional 2013 GS 350 is now the same as the combined cycle fuel economy was for the earlier version of the GS 450h hybrid.)

The second generation of the Lexus Hybrid Drive system applied in the new GS 450h features a next-generation D-4S direct and port fuel injection system with an Atkinson cycle 3.5-liter V6 engine mated to a compact, high-output, water-cooled permanent magnet electric motor powered by a high performance NiMH battery pack. The two powerplants drive the rear wheels both independently and in tandem, as needed. Total system output is 338 hp (252 kW).

Features of the powertrain include:

  • Improved fuel consumption is achieved through a high compression ratio of 13:1, a new mid-port intake tumble generator and the adoption of a Lexus four-stroke, direct injection technology, D-4S.

  • With one injector installed in the combustion chamber and a second mounted in the intake port, D-4S combines the strengths of both direct and port injection, realizing optimum engine efficiency throughout the power band and improving torque across the rev range, while minimizing fuel consumption and emissions.

  • The D-4S system features new slit-type injector nozzles with a modified port shape, a higher fuel pressure for more efficient combustion, and idle port injection for improved NVH characteristics.

  • The cooling performance of the hybrid system’s Power Control Unit (PCU) helps reduce fuel consumption and has been improved through the adoption of dual cooling paths and a single-piece, integrated DC/DC converter.

  • The PCU boosts motor drive voltage to a maximum 650V in Sport mode and limits it to a maximum of 500V in Eco mode under normal driving conditions where maximum output is not required. The motor is driven at lower voltage to provide a more environmentally advanced driving performance to help enhance fuel efficiency.

  • The system’s regenerative braking operation range has been expanded, contributing to further improvements in fuel efficiency.

  • A new stacked battery configuration maximizing luggage space allows the 2013 GS 450h to have more cargo area than the previous generation GS 350.

  • Acceleration from 0-60 mph in 5.6 seconds.

  • Super-Ultra Low Emissions Vehicle (SULEV) certification.

  • Engine noise, vibration and friction have been lowered through the adoption of lightweight timing chain technology.

The GS 450h has five driving modes that can be operated by toggling the new Lexus Drive Mode selector. In addition to the Normal mode, the following settings let the driver customize the driving experience:

  • ECO mode revises throttle mapping, seat heating, and climate control systems for better fuel economy. In ECO mode, meter lighting changes to blue.

  • EV mode allows the vehicle to be driven short distances, under certain circumstances, using only the electric motors.

  • SPORT S mode revises throttle mapping and transmission shifting priorities to fully exploit the capabilities of the powertrain. In SPORT S mode, meter lighting changes to red.

  • SPORT S+ mode engages handling enhancements via a sport setting of the adaptive variable suspension, steering system, and Vehicle Dynamic Integrated Management (VDIM) together with the powertrain enhancements of SPORT S mode.



Tell some of the old muscle car owners about 338 hp and over 30 mpg. That dog hunts.


a: This is all good.
b: How much does it cost?
c: How about a lower power version
- do you really need 0-60 in 5.6 seconds ?
- How about a 2L 4 cylinder giving 0-60 in 8 seconds?
d: Will it trickle down and up to the rest of the Lexus range ?


2013 Lexus GS Hybrid 450h
MSRP $58,950


Yes mahonj...2 versions would be better to satisfy different needs.

This high power muscle version appeals to those who are convinced that a car should do 200+ kph and 100 kph in less than 6 seconds like a race car should.

The majority would be satisfied with a top speed of 140 kph and 100 kph in 10 seconds or so and 41+ mpg instead of 31 mpg.

Roger Pham

Agree, HarveyD.
The GS 450 hybrid version should have a Camry-hybrid engine of 2.4 liter Atkinson cycle, with total of 200 hp instead of 338 hp. This should give it about 40-45 mpg overall efficiency. The car will also be much lighter and better maneuverability. Why force too much power on the hybrid version? Those who want high power can buy the non-hybrid version, since they won't be able to take full advantage of a hybrid drive train if always "full metal to the pedal!"



Cars are about emotion, not rationality. That's why they have these ridiculous amounts of power. Even if you never use it, if somehow feels good knowing you could easily beat that Cruze or Fusion standing next to you at the traffic lights. Apparently, the more green-leaning rich people don't lose that urge (and it explains a lot why the Model S is so popular).



They do sell a similar car that uses the Camry Hybrid powertrain. It's called the Camry Hybrid (or ES300h if you want a Lexus badge).
The Camry Hybrid doesn't get 40-45 MPG, so I'm not convinced that the GS would do that with the same powertrain.

John DeCicco

That's right; we just bought a new Camry Hybrid and in its fully loaded guise its features are pretty close to those of the ES300h. We ogled the Lexus but didn't test drive it -- low $30's is as much as we've ever paid for a car ever! But 40-45 mpg, no; we've been averaging 39 mpg so far in mixed driving including one long road trip. The 200 hp performance is fine enuf for me, but I can understand how some others out there will want the potency of a 450h. The performance-efficiency trade-off never goes away, it just rocks at an ever higher pivot point.

Roger Pham

2012 Camry hybrid is rated at 44mpg city and hwy. If the drive train is mated to a large frame of the GS 450, it still should be capable of around 40-42 mpg. 200 hp is a lot of power for a 4000-lb car. My 1978 Chevrolet Caprice station wagon was above 5000-lb curb weight and acclerated very fast with a 5.6 L 170-hp engine with a 3-speed Hydramatic transmission. Likewise, my father's 1982 Toyota Cressida weighing about 3200 lbs accelerated even faster with only a 145 hp I-6 twin cam 24-valve DOHC. Those wanting more power should be happier with a 338-hp 8-speed transmission non-hybrid GS-450.

Roger Pham

HEV mfg's should remember the market failures of over-powered, over-priced, over-weight and not-high-enough-mpg luxury HEV's, while the super-high-mpg, affordable and light-weight HEV's are selling super well. Ford Fusion hybrid is going in the right direction by reducing the engine size while upping the MPG, and the C-Max hybrid strikes a good balance between hp, size, weight and affordable cost.



Check the EPA site. None of the 3 versions of the Camry Hybrid (LE, XLE, ES300h) get 44. They come close, and I'm sure some owners will beat 44 occasionally, but it's best to stick with the official figures.

Roger Pham

You are right, Bernard.


The 2013 Ford Fusion (and derivatives) will do 44+ mpg.


Correction ....should read...Ford Fusion Hybrid.....

The comments to this entry are closed.