Despite Honda’s reputation for building great engines, the Japanese automaker has been slow to adopt direct injection (DI). The technology is now commonplace in all segments of the market, and allows for higher compression ratios and therefore improved efficiency. At an event surrounding the Tokyo auto show, Honda has told us that it is finally ready to add this feature to its engines. Besides DI, the engines also will feature a stop/start system.
At the top of the line is a redesigned 3.5-liter V-6, which features cylinder shutdown and a two-stage oil pump. With at least 308 hp and 266 lb-ft of torque, this engine delivers more power than Honda’s existing 3.7-liter engine and should yield a fuel-economy improvement of about 10 percent.
Another highlight of the lineup is a new 1.6-liter turbo-diesel, which is meant to replace the current 2.2-liter oil-burner found in markets outside of the United State. It’s claimed to be as light as a gasoline engine; the all-aluminum design features an open-deck block, which shaves pounds but is less stiff than the closed-deck design normally seen on diesel engines. Still, Honda claims the weight savings come without any long-term reliability concerns, thanks to new high-strength aluminum alloys, a stiff head design, and optimized cooling. Output figures of 118 hp and 221 lb-ft of torque are impressive for the downsized displacement. Alas, Honda executives are silent on whether or not we’ll ever see this engine in North America.
We also saw a 2.4-liter inline-4 that makes at least 181 hp and 177 lb-ft of torque. Compared to the current, port-injected 2.4-liter four in the new CR-V, those numbers represent a drop of 4 hp but an increase of 14 lb-ft; the differences are negligible enough, however, that we’d expect similar performance with better fuel economy. The outputs of Honda’s DI-equipped 1.8-liter and 1.5-liter fours are likewise similar to their current port-injection equivalents.
You Can’t Spell Continuously Variable Transmission Without Three of the Letters in “Honda”
Honda also announced a new series of continuously variable transmissions that supposedly reduce the annoyances we expect of this type of gearbox. The new CVTs—one is intended for mid-size and compact cars, the other for Japanese-market microcars—promise quicker response to throttle inputs, which should mean smoother acceleration and less of the irritating rubber-band feeling that occurs when the engine revs climb before there’s any noticeable change in speed. It’s a story of incremental gains here, made mostly through a wider belt (30 millimeters versus the current Honda CVT’s 24 mm) that reduces surface pressure, redesigned grooves in the pulley that better retain transmission fluid, and more precise control of the hydraulic pump. The ratio spread also is increased for better fuel economy.
When exactly we’ll see these engines and transmissions in showrooms hasn’t been announced, but we expect them to start entering the lineup sometime in the next two years. In typical fashion, Honda won’t make any claims about actual efficiency numbers or performance relative to its competitors, but we suspect that these updated powertrains will burnish Honda’s engine-building reputation and put its cars near the top of the fuel-economy heap.
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