Preview: Lexus takes enormous step forward with new IS

Looking past the camouflage, the new car earns the Lexus Spindle grille and LED daytime running lights. The interior was equally heavily camouflaged, but it was obvious that the cabin will mimic that of the larger GS, complete with the dash-mounted screen to the right of the central cluster. The new IS also features a single dashboard dial. The tachometer rings on the outer edge with the fuel economy, Drive Mode Select (more on this in a moment) and speedometer readouts sitting in the centre. It is an attractively clean and concise way of relaying all the relevant information.

Mr. Furuyama believes the new IS350 surpassed the present 3 Series in its fun-to-drive quotient. He is not wrong

The location and angle of the steering wheel has also been tweaked to improve the driving position. This and the new deep-dish style front buckets held me in place when the IS was pushed around a rally cross-style circuit in the parking lot of Santa Anita race track and on a fast run up a boulder-strewn canyon road — the heavy rain had initiated some pretty serious rockslides.

The more substantial work is found beneath the IS’s sheet metal. It starts with the body structure. Overall length is up 75 millimetres, the wheelbase grows by 70 mm and the width by 12 mm. The stretch in the wheelbase has been dedicated almost exclusively to the rear seat riders meaning the IS’s rear leg space now rivals that of the larger GS. Likewise, the platform has been strengthened through the use of structural adhesives, an increased number of spot welds and a new laser screw welding technique. Statically, the torsional rigidity is up 10% — the reality is the newfound stiffness has a greater effect on the dynamic aspects than that number suggests.

The stiffer platform improves both the ride quality and handling because it gives the new suspension a stronger base of operations. Up front, the double wishbone design has been retained, however, the stabilizer bar link has been reworked, which increases its rigidity by 20%. The IS’s new rear suspension was plucked directly from the GS. The new setup, especially with the optional active dampers aboard, does a very good job keeping the rubber on the road —P225/40 R18 front and substantial P255/35R18 rear tires on the test car. The steering has also been refined. Again, the starting point was the GS’s rack, however, further work has sharpened the on-centre feel and made the rack ratio faster. This brings better feedback without making the IS350 seem twitchy. It also adds much better straight-line stability. The final dynamic touch is found in the IS350’s larger front rotors and performance brake pads.

The vehicle tested was an IS350 F Sport. In this version, the spring rates remain the same as the stock suspension — it is the variable dampers that make the difference. The key is the driver’s ability to tailor various drivetrain aspects through the Drive Mode Select system. It offers Eco, Normal, Sport and Sport+ modes. Eco makes the throttle too soft, so it will see little use unless fuel economy is paramount. The normal mode is fine, although a faster reaction to throttle input would be appreciated. Sport speeds up the throttle response and tweaks the transmission’s shift points to make things feel far more urgent.

The best mode proved to be Sport+. It not only makes the throttle and transmission changes, it alters the steering’s weight and ratio as well as changing the dampers settings. This brings the best of both worlds — in the normal mode, the damping is 15% softer than the regular suspension, which makes the ride comfortable; Sport+ sharpens the damping so it 15% firmer than the regular suspension.

Mr. Furuyama says the main benchmark for the new IS was the previous-generation BMW 3 Series — he noted the current 3 Series was softened to make it more comfortable. As such, Mr. Furuyama believes the new IS350 surpassed the present 3 Series in its fun-to-drive quotient. He is not wrong.

Testing proved the IS350 to be noticeably crisper. The steering is much sharper and it turns in with more authority. The improvements were made all the more noticeable on the rain-soaked skid pad. There was very little body roll and less understeer when the IS was pushed as far as the conditions permitted. A g-force meter backed up all of my seat-of-the-pant evaluations. On the wet tarmac, the current IS350 available for testing pulled 0.81g before the stability control system intervened. The new IS350 F Sport prototypes were pulling 0.91g before stability control intervention. Now, that is a significant and quantifiable improvement.

While the engines carry over from the current cars, there is an important upgrade for the IS350 — the addition of an eight-speed transmission (the IS250 retains the previous six-speed box). In the acceleration portion of the skid pad test, the current car put 103 kilometres an hour on the speedometer before hitting the braking zone — the new car with its extra ratios was showing 114 km/h when it hit the same point. The difference is found in the taller first and second gear ratios. They give a noticeably faster launch and a much stronger mid-range. The transmission will also have a positive effect on fuel economy. The canyon drive proved the new car is very quiet. However, an intake noise attenuator ensures the driver hears the right noises when it’s appropriate.

The next-generation IS will make its debut appearance at the North American International Auto Show in January. Full specifications, content and pricing will be available at that time.

courtesy of nationalpost.com