Tech preview: The 2003 imports

Motor,  Dec 2002  by Weissler, Paul

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Innovative technical features of the import class of 2003, including a high-capacity CVT and a W8 engine, promise fresh challenges for independent repair shops.

The Honda Accord is such a best-seller that even if it were the only all-new import nameplate for 2003 it would be significant. However, there's a lot more, of course, including the new Mercedes E-Class and CLK, the Saab 93, the Mazda 6 and the Subaru Baja. There's also a revival of the Nissan Z, an Altima-based Nissan Murano SUV, plus three Infiniti rear-drive models.

Under the hood are the first W-shaped engine, the W8 sulphur fuel (available only in California at this time).

The electronic/hydraulic engine mount long used by Honda fours and located at the rear now is on the front side, apparently in part because of the engine's 180 deg rotation. The entire mounting system, however, also was reengineered.

As part of Honda's across-the-board improvements in emissions control, however, all four-cylinder engines and the redesigned V6 have the more precise linear air/fuel ratio sensors, not the conventional toggling-voltage type.

The V6 still has a timing belt, but the engine has been extensively reworked in other respects, and produces 240 hp, up 40 from 2002 models. It has a three-lobe variable-lift setup on the continuously variable intake camshaft. This arrangement, which has been used on high-performance models in the past, permits tailoring both intake valves' lobes more precisely for low- to mid-rpm operation, and then locking them to a third lobe with a high-performance profile.

One of the novel aspects of the V6 is integration of the exhaust manifolds with the cylinder heads. It not only eliminates a gasket joint, but improves engine packaging and helps with close coupling of the primary catalytic converters, for low emissions. The V6 also has an electronic throttle and coil-on-- plug ignition.

The four-speed automatics are gone, replaced by two five-speeds. The one for the 3.0 V6 is not the same as the one coupled to the four-cylinder, but it's very similar to the transmission in the Acura TL with the 3.2 V6, with modifications to use the electronic throttle to torque-manage the shifts for smoothness.

There's a new lightweight five-speed manual, plus a six-speed adapted from the one in the Acura CL with the 3.2 V6. This box uses a hydraulic clutch mated to a dual-mass flywheel.

The new Accord is a "CAN" car-in fact, it has both high-speed and low-- speed CANs. The gateway module for both CANs is located in the instrument panel. According to Honda service training, the early report is that OBD II diagnostics will continue to be displayed on generic scan tools.

If you want to take the plunge into gasoline-electric hybrids, the first Honda "mainstream" car is out-the Civic Hybrid. The electric powertrain is a modified version of the one in the Honda Insight, but the engine is a new 85-hp, 1.3L four-cylinder, compared with the 67-hp, 1.0L three-cylinder in the Insight. Horsepower goes up to 93 on the Civic (73 on the Insight) when the Integrated Motor Assist electric drivetrain comes in. Both Honda hybrids offer a choice of five-speed manual or a CVT (continuously variable transmission), similar to what has been offered on the regular Civic for several years. The Civic Hybrid joins the Toyota Prius as a "real" car (as opposed to the minimalist Insight).

Nissan and Infiniti are getting wide use of the 3.5L V6, produced in various stages of tune from 240 to 287 hp. You'll find it in every transverse frontdrive from the Altima to the Maxima to the Infiniti 135. For 2003, it's been reworked for rear-drive, so you'll also see it in the 3502 sports car and the new G35 sports sedan and sports coupe. Although there may be a large number of interchangeable parts, naturally, there are differences in intake and exhaust systems and electronic controls because of tuning differences and orientation. The higher numbers are for the rear-drives.

The Z car is rated at 287 hp and 274 ft-lb, the G35 sport coupe V6 very close at 280 hp (260 ft-lb of torque). The G35 sport sedan V6's numbers are 260 hp/246 ft-lb. The transverse-frontdrive Altima V6 is 240 hp/246 ft-lb; the Maxima and Infiniti 135 both are 255 hp/246 ft-lb.

You also may notice a pair of underhood decals on the new rear-drives. The one on the V6 warns against the common practice of pulling the dipstick while adding engine oil. Reason: The oil dipstick is in one of the oil drainback channels, very close to the oil fill neck of the No. 2 (driver's side) cylinder head. If there's residual crankcase pressure after engine shutdown, pulling the stick with the fill cap off could result in oil burping out of the dipstick tube, creating a mess.

The other-on the rear-drive automatics-notes that the rear-drive RE5R05A five-speed automatic transmission in the G35 series is factory-- filled with Type J fluid, a new fluid with tailored frictional characteristics to smooth out and also ensure good engagement of the torque converter clutch. It may be similar to some of the other special fluids designed for that purpose, but no one at Nissan can say for sure. In the meantime, other Nissan automatics use Type D fluid, for which a premium Dexron/Mercon fluid is an acceptable substitute, according to Valvoline's Scott Wieland.