The newest (and only one currently in production) of Toyota’s V6 engine families is the GR. Launched in 2002 as the 4-liter (3956cc) 1GR-FE on the Land Cruiser Prado / 4Runner / Hilux Surf family of body-on-frame sport utility vehicles, it eventually spawned smaller 2GR (3.5-liter/3456cc), 3GR (3-liter/2994cc) and 4GR (2.5-liter/2499cc) variants, as well as China-only 5GR (2.5-liter/2497cc, with a larger bore and shorter stroke than the 4GR) and 6GR (essentially the same as the 1GR) iterations.
The 1GR-FE was introduced with VVT-i (Variable Valve Timing with intelligence) on the intake cam only, but was eventually updated to Dual VVT-i that adjusts timing on both intake and exhaust camshafts, with the 2015 Toyota Tacoma pickup and Fortuner SUV being the last holdouts with intake-only VVT-i. The FE suffix in the engine code denotes a narrower angle, economy-oriented DOHC (Dual OverHead Camshaft) valve train layout in conjunction with the use of port-only electronic fuel injection.
None of the GR V6 engine family members, however, are available in as many variations as the 3.5-liter 2GR. Besides being installed in a bewildering array of transversely-mounted front-wheel-drive and longitudinally-mounted rear-wheel-drive (not to mention optional all-wheel-drive for each) vehicle applications encompassing cars, trucks and crossovers, there are four distinct versions of the 2GR. The 2GR-FE, like its 1GR-FE big brother, uses indirect port fuel injection only. Unlike the truck and SUV-only 1GR, however, the 2GR-FE’s primary use is in transverse FWD K-platform Toyota Camry derivatives. Larger RWD N and New N platform sedans and coupes such as Lexus IS, RC and GS as well as Japan’s Toyota Mark X and Crown models, in contrast, get an FSE suffix denoting the use of D4-S dual port and direct injection. Hybridization, or the addition of supplementary electric motors and battery pack, uses a 2GR-FXE engine code. This is used regardless of whether the basis is the port injection-only 2GR-FE (Toyota Highlander Hybrid and Lexus RX 450h) or the dual direct + port injection 2GR-FSE (Lexus GS 450h and Japan’s Toyota Crown Majesta Hybrid). And the fourth 2GR V6? We’ll get to that in a bit, but first…
A correction and a clarification
In a recent Kaizen Factor story on Lexus’ newest trademarks, we reported that the 2016 Toyota Tacoma pickup truck would offer an optional 3.5-liter non-hybrid V6 with dual Atkinson and Otto cycle capability and equipped with Toyota’s D-4S technology, featuring both direct and port fuel injection. Based on an April 2015 “Toyota/Scion tentative 2016 Dealer Model Reference” page that mentioned a 7GR engine code for 2016 V6 Tacomas, and the recent launch of what is essentially a naturally-aspirated version of the Lexus NX 200t engine that nonetheless includes D-4S direct + port injection, Atkinson-to-Otto cycle capability and electric VVT-iE with a 6AR-FSE engine code, we concluded that the newest version of the 2GR V6 would bear a 7GR-FSE engine code. Four days after publishing our story, however, Canadian Toyota parts advisor Jeff Lange uncovered the first of numerous documents revealing a more logical 2GR-FKS engine code. Toyota has been maddeningly inconsistent in applying the K to its engine codes, let alone officially confirming that the K denotes Otto-to-Atkinson cycle capability in a non-hybrid engine. While the K has been applied to the latest versions of the NR 4-cylinder engine family, we’ll argue that the aforementioned naturally-aspirated version of the 8AR-FTS 2-liter 4-cylinder Lexus turbo engine should’ve borne a 6AR-FKS engine code instead of the 6AR-FSE it’s been given; and that the Lexus IS F’s 2UR-GSE 5-liter V8, when upgraded for the RC F and upcoming GS F with dual cycle capability and added power should’ve been renamed 2UR-GKS.
From FSE to FKS: more than just dual Otto/Atkinson capability
Although the ability to alternate between modified Otto and Atkinson cycles is the major upgrade in the transition from FSE to FKS, it’s hardly the only change. This dual capability is facilitated by an upgrade from the old Dual VVT-i to VVT-iW on the intake camshafts (the W denotes the wider or expanded valve opening angles that increase fuel-efficiency at low engine loads) and “regular” VVT-i on the exhaust camshafts. Exploring Overland‘s Jonathan Hanson does a great job of explaining the 2GR-FKS’s technical intricacies. Other upgrades include a new reduced-friction oil sump and an exhaust manifold integrated into the cylinder head, a design whose benefits include lighter weight, the ability to use engine coolant to cool exhaust gasses and a structure that can make the addition of a turbocharger easier. (Don’t get us started on the traditional difficulty on cracking Lexus GR V6 ECU codes, though…) To quote Toyota Tacoma chief engineer Mike Sweers:
“One of my favorite parts of the engine is we eliminated the exhaust manifold on the engine and put that into the head of the cylinder head itself. So by doing that we can cool the exhaust gas. And by cooling the exhaust gas I don’t have to pump any raw fuel into the catalyst to keep the catalyst cool, because I’m not heating the catalyst up as much.”
A side benefit of the design: the catalytic converter is closer to the head, making theft less likely.
Yet, there is one more significant upgrade uncovered by Christie Schweinsberg of WardsAuto: self-cleaning fuel injectors that neatly solve the carbon buildup bugaboo that ails many direct-injection engines (including the Lexus IS 250’s DI-only 4GR-FSE). While decreased carbon buildup is touted as one of several benefits of the more complex D4-S dual direct + port injection used on the 2GR, it’s still not a panacea. As Mike Sweers explained to WardsAuto:
“…we have a slit on the side of our injector and we’re blowing that carbon off. If we tried to use just high pressure, using just the nozzle itself, you would clean the bottom of that nozzle. But since the carbon grows from the outside and comes around, you would still plug up that injector. So by cleaning on the outside of that, we get a clean injector all the time.”
Drivers may hear the self-cleaning taking place during a hot idle, and the process could last from 10 seconds to as long as 10 minutes, depending on driving patterns and the amount of build-up on the injectors.
“When you go into a hot-idle situation, the system is going to look at the time that it ran, the number of cycles the injectors went through, the temperature of the injectors and then it goes into a self-cleaning mode. Because we have the port injection, I can continue idling the engine without having any side effects.”
He compares the technology to a self-cleaning oven, as no additives are necessary.
“You stop at a light (and) it may clean for 10 seconds, you’re going to take off and stop at another light and it’s going to clean for (another) 10 seconds…
The 10-minute cleaning cycle occurs during longer idling, such as in a drive-thru line.
The 2GR-FKS in the Toyota Tacoma…
Although the port injection-only, intake-only VVT-i 1GR-FE from the outgoing Toyota Tacoma is exactly 500cc larger, its smaller, but far more feature-rich successor gains 42 horsepower (278 versus its predecessor’s 236) and loses but a single foot-pound of torque (265 for the new 2GR-FKS). The new V6 is definitely more of a car-like high-revver. The redline is 700 rpm higher (6200 rpm for the new 3.5 vs 5500 for the outgoing 4.0), peak horsepower comes 800 rpm higher (6000 rpm for the new 3.5 vs 5200 for the outgoing 4.0) and torque now peaks at 4600 rpm (versus 4000 rpm for the 1GR-FE). A maximum tow rating of 6800 pounds is 300 lbs higher than before.
The new V6 also produces improved fuel economy numbers, up to 2 mpg city and 3 mpg highway better than the outgoing 4-liter, depending on transmission (manual or automatic, both with 6 speeds) and whether number of driven wheels (RWD or 4WD). That 3 mpg highway improvement is evident on the 2-wheel-drive Tacoma automatic. 87-octane regular fuel is fine, but the new Tacoma will have to overcome not only both horsepower and fuel economy deficits, but inferior rear drum brakes and a less solid C-sectioned frame in its battle with the new and resurgent Chevrolet Colorado / GMC Canyon mid-sized pickup twins that are superior in all those regards. Resting on Toyota’s traditional reliability and durability laurels alone is hardly in keeping with the spirit of kaizen…
…and in the Lexus GS 350
The other recipient of the new 2GR-FKS 3.5-liter V6 is the 2016 Lexus GS 350 as part of the 4th-gen GS’s midlife refresh. In fact, only the GS 450h’s 2GR-FXE powerplant remains untouched, given that the GS line is augmented by a GS 200t (powered by the 8AR-FTS 2-liter 4-cylinder turbo) on the low end and a GS F (powered by the 2UR-GSE 5-liter V8) on the high end. Since the GS 350’s prior 2GR-FSE is closer in specification to the new 2GR-FKS than the old vs new Tacoma V6, the 2016 non-hybrid V6 GS sees negligible improvement. As yours truly recently noted on my.IS:
Unfortunately, gains produced by the 2GR 3.5-liter V6 as it morphs from FSE to FKS are nowhere near as lofty or significant. Here, we’re talking a mere 5 horsepower and 3 lb/ft of torque gain, unchanged acceleration times and a mere 1 mpg improvement in highway and combined fuel economy for the 2016 GS 350 AWD versus its 2015 predecessor. Numbers for the RWD GS 350 are a mixed bag, with a single set of 19 mpg city / 29 mpg highway / 23 mpg combined numbers being given for 2015, versus 20/29/23 mpg numbers given for the “regular” 2016 GS 350 RWD and 19/28/22 for the 2016 GS 350 RWD F Sport. Those differences are much more a function of different tire and wheel sizes (18″ diameter for the standard GS versus 19″ for the F Sport) than any mechanical differences. For years, Europe has noted the adverse effect of larger wheels and tires on CO2 emissions numbers and fuel economy, but this is the first tacit admission of same this author has seen in U.S. EPA fuel economy numbers.
But what about the different numbers between the Toyota Tacoma and the Lexus GS 350’s 2GR-FKS applications? Why only 278 hp and 265 lb/ft of torque for the Tacoma when the GS 350 produces 311 hp and 280 lb/ft of torque? Primarily, it’s the Tacoma’s tuning for regular gasoline versus the GS 350’s requirement for premium, combined with the truck’s prioritizing low-end grunt and maintaining torque versus the car’s more rev-happy, high-end power tuning.
Where will the 2GR-FKS go next?
With 2016 Lexus IS 350 specifications having been released, we can confirm that it keeps the older 2GR-FSE V6 for now. (Expect the upgrade to FKS next year, as part of the IS’s scheduled midlife refresh). As of this writing, Lexus has not released 2016 RC 350 coupe specifications, but we suspect it’ll follow the IS pattern in keeping the older FSE engine for now. Thus, the next vehicle to receive the 2GR-FKS will probably be a significant and somewhat unexpected one: the new-for-2016, 4th-generation Lexus RX. The press release issued upon its debut at the 2015 New York Auto Show stated that the RX 350 would have a “more powerful 3.5-liter V6 aiming to deliver 300 hp with direct injection”. Significant and somewhat unexpected because, at a minimum, it would be the first transverse engine / FWD-centric V6 Lexus or Toyota model to feature direct injection. Left unclear is whether this is direct injection-only à la 4GR-FSE IS 250 or D4-S dual direct + port injection as used on the 2GR-FKS. We’re betting on the latter…
A return to WardsAuto’s 10 Best Engines list?
Toyota and Lexus’ 2GR-FSE 3.5-liter V6 was selected by WardsAuto for its annual 10 Best Engines list 4 years running, in 2006, 2007, 2008 and 2009, after which the Lexus 2GR fell off the list, citing the ever-competitive creation of new engines and, perhaps, a slight bias towards smaller 3 and 4-cylinder turbos and hybrid and electric powerplants. Might the new upgrades be significant enough to earn it a return to the 10 Best Engines list? We should know by the end of the year. Based upon last year’s rules, last year’s 10 Best Engines winners plus any engines or propulsion systems that are all-new or significantly re-engineered and available in the U.S. market in vehicles with a base price not exceeding $60,000 and available for sale no later than the first quarter of 2016 are eligible. Said vehicles will be evaluated by as many as
Eight WardsAuto editors (that will drive) the vehicles in October and November (2015) in their routine daily commutes around metro Detroit.
Editors score each engine based on power, torque, technology, observed fuel economy, relative competitiveness and noise, vibration and harshness characteristics.
The 10 Best Engines winners for 2016 should be announced in late December 2015 and the awards will be presented at a ceremony in Detroit during the North American International Auto Show press conferences in January 2016. Will the Toyota / Lexus 2GR V6 regain a 10 Best trophy? Fingers crossed…