Toyota Brings Stop-Start to U.S. on Highlander, Expands D-4S

OJAI, CA – Toyota will introduce stop-start to the U.S. for the first time outside of a hybrid application on the ’17 Highlander midsize CUV.

While the automaker is late to the party on the technology here, it offers stop/start on an estimated 40 Toyota non-hybrid models in various markets around the globe.

Recognizing stop-start has been a controversial technology, as consumers and reviewers have complained about the shock and vibration of some automakers’ systems during engine restart, Brian Williams, product specialist-marketing, products and communication for Toyota Motor Sales U.S.A., is quick to note how much effort Toyota put into its version to avoid buyer blowback.

“The chief engineer spent a lot of time trying to get that engine-on timing to be very smooth and very preferable for our customers,” Williams says. “You’re also going to get the benefit of reduced emissions and in some cases reduced fuel consumption, based on your city driving,” he says.

As with other automakers’ systems, an up-to-1 mpg (0.4 km/L) improvement in city driving can be realized by leaving Toyota’s stop-start system on. If buyers would rather not use it, the system can be turned off via a button on the Highlander’s lower dash after each ignition cycle.

The Highlander is the first, but not the last, Toyota to get stop-start in the U.S. However, Toyota Div.’s Bill Fay, U.S. group vice president, says the automaker doesn’t intend to blanket the market with the technology, but rather take a surgical approach to its introduction.

“Not to minimize stop-start, but we feel there’s much more of a consumer value with (our advanced safety technology),” Fay says here during a ’17 Highlander media preview.

Adds Williams: “We’re not hesitant about it. This is just the first iteration in North America with our new motor.”

The Highlander’s new motor is Toyota’s 3.5L Atkinson-cycle-capable V-6 with its D-4S port- and direct-injection technology. Last year, the ’16 Tacoma midsize pickup became the first Toyota-brand model in the U.S. to get D-4S. It originated in the U.S. on the ’05 Lexus GS and in 2012 came to market on the 4-cyl. Scion FR-S sports car, which for ’17 becomes the Toyota 86.

All ’17 Highlanders get the 3.5L V-6 with D-4S barring the base LE grade which carries over its 2.7L 4-cyl.

For CAFE compliance, the Sienna also adds the 3.5L V-6 with D-4S for ’17, but because the vehicle underwent what is considered a model-year change compared with the Highlander’s mid-cycle refresh, Toyota did not allocate funding for in-dash electronic updates to add stop-start to the minivan, Williams says.

New Automatic, Tires Boost Fuel Economy

The D-4S, which can alternate between port and direct injection in lower-mid range rpms and uses only DI in upper rpms, is just one of the tools Toyota uses to improve the ’17 Highlander’s fuel economy.

The CUV also gets a new 8-speed automatic transmission for ’17, a product of the automaker’s Toyota New Global Architecture initiative to optimize engineering and manufacturing efforts.

The “direct feel” 8AT, which weighs less and has a lower center of gravity than the 6-speed automatic it replaces, uses a multi-plate-clutch-type torque converter making possible lockup from second to eighth gear, all controlled via a dedicated hydraulic lockup circuit.

“Usually on automatic transmissions you un-lockup the converter to shift so it’s smoother to prevent vibrations,” Williams says. “Ultimately, when you do that you lose some of the efficiency and power transfer from the engine to the output. (With this design), power’s coming in, there’s less lag during shifting (and) it’s more rapid shifting.”

Low-rolling-resistance tires, with an increase in tire pressure also boost Highlander’s fuel economy from ’16 to ’17, as do friction improvements to the V-6’s block.

For ’17, the Highlander gets an EPA-estimated 21/27/23 mpg (11-9-10 L/100 km) city/highway/combined in front-wheel-drive variants, an increase of 2 mpg (0.9 km/L) across the board from ’16.

All-wheel-drive Highlanders net 20/27/23 mpg (12-9-10 L/100 km) city/highway/combined, an increase of 2 mpg city and 3 mpg (1.3 km/L) in highway and combined metrics.

Williams says stop-start is factored into the CUV’s city fuel economy rating for ’17.

Toyota continues to offer a Highlander Hybrid, which sees additional trim levels for ’17 and fuel-economy increases of 3 mpg city and 1 mpg in combined driving.

Despite being shared with the Tacoma, the 3.5L V-6 with D-4S has unique tuning for the Highlander. In the CUV it churns out 295 hp, which Toyota says bests the Honda Pilot and others in its class. That’s also up 25 hp from the ’16 Highlander and 17 hp from the ’16 Tacoma.

Torque rises 15 lb.-ft. (20 Nm) from the ’16 CUV to 263 lb.-ft. (357 Nm) and just 2 lb.-ft. (3 Nm) shy of Tacoma.

The 3.5L V-6 with D-4S mated to the 8AT in the Sienna makes 296 hp and 263 lb.-ft. of torque, up 30 hp and 18 lb.-ft. (24 Nm), respectively. Sienna FWD fuel economy grows to 19/27 mpg (12-9) L/100 km) city/highway, up from 18/25 mpg (13-9 L/100 km) in ’16.

The new engine is the only update to Sienna for ’17, while the Highlander also gets a new 8-passenger seating layout in addition to its 7-passenger seating, new SE (unique black-leather seating and a gloss black grille) and Limited Platinum (plusher interior and a standard Bird’s Eye view camera) grades, four additional USB ports (bringing the total to five) and LED brake lights and taillights.

The ’17 Sienna is available now at Toyota U.S. dealers while the Highlander arrives in November.

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