Equipped with an EPA Tier 4 Final certified engine, the new WA600-8 wheel loader from Komatsu combines an enhanced lockup torque converter function and SmartLoader logic to achieve low fuel consumption and high travel speeds. It now incorporates many of the features of the smaller construction class wheel loaders such as KOMTRAX, upgraded cab features, and improved operator comfort, Bruce Boebel, Senior Product Manager, Komatsu America Corp., told Off-Highway Engineering.

“This model represents the largest Komatsu construction class model and is the transition point between use at smaller quarries and large mines,” Boebel said. “It can be used for v-cycle work or equipped with a load and carry spec. Various tire and bucket options make it highly adaptable to many customer operations and applications.”

By optimizing control of engine power and improving powertrain and hydraulic efficiency, the WA600-8 consumes up to 13% less fuel than its Tier 3 predecessor. To aid worksite productivity and machine efficiency, engineers designed a new bucket that reportedly fills easier, retains material better, and provides better visibility. The standard bucket capacity increased to 9.2 yd³ (7.0 m³). An enhanced auto-dig function reduces the operator effort required to fill the bucket.

“The new Komatsu bucket has an improved profile, allowing for a 7% increase in capacity versus the WA600-6 buckets,” said Boebel. “The new auto-dig feature helps less experienced operators be more productive faster.”

Powering the new wheel loader is a 23.15-L, 529-hp (395-kW) SAA6D170E-7 engine, which incorporates a KVGT (Komatsu Variable Geometry Turbocharger), heavy-duty EGR (exhaust gas recirculation) system, and KCCV (Komatsu Crank Case Ventilation) filter.

Designed in conjunction with the engine are the Komatsu Diesel Particulate Filter (KDPF) and other aftertreatment components like the SCR (selective catalytic reduction) system and the DEF (diesel exhaust fluid) mixing tube. More than 98% of KDPF regeneration is performed passively, with no action required of the operator and no interference with machine operation.

Komatsu’s SmartLoader Logic, combined with the large-capacity lockup torque converter that activates in 2nd, 3rd, and 4th gears, provides optimal engine torque for improved acceleration, hill-climbing ability, a higher top speed—25.5 mph (41.0 km/h) vs. the previous WA600-6’s 23.4 mph (37.7 km/h)—and fuel savings. Another fuel-saving function is Auto Idle Shutdown, which reduces idle time.

“All of the Komatsu wheel loaders have Power and Economy operating modes to match the power to the job. While testing in E mode, Komatsu has seen up to 13% less fuel consumption as compared to the WA600-6 model,” Boebel said.

To improve traction on various ground conditions, the WA600-8 features Variable Traction Control and a modulated clutch system. “The modulation clutch allows smooth speed control to load trucks, controls tire slip, and reduces driveline shocks without slowing work equipment hydraulic speed,” Boebel said.

“With significant enhancements in production capacity and fuel economy, the WA600-8 is designed to maximize production efficiency in loading off-highway trucks or load-and-carry applications,” said Rob McMahon, Product Manager for Komatsu America. “Full rear fenders with steps and handrails at both sides of the machine add convenience for daily inspections.”

Among many factors influencing development, customer feedback played a “pivotal role,” according to Boebel. “For example, the addition of the handrails on both sides of the machine was the direct result of customer input.” The WA600-8 was a multi-year project that involved rigorous testing and machine validation.

Asked about any major development challenges, Boebel replied, “Anytime that there is a major redesign in a model, real estate always becomes a major challenge. How do you add space for aftertreatment systems, an additional walkway, and other new components but still have excellent access and maintainability? Komatsu engineers met that challenge. Access is excellent on this machine.”

Features that aid maintenance and access include a swing-out cooling fan with wider fin spacing and reversing fan for easier cleaning, a sight gauge at the DEF fill cap to help prevent overfilling, and additional hinged panels at each side of the machine to ease access to regeneration components.

In-cab enhancements compared to the previous model include a high-back, air-suspension heated seat with cast frame members that reportedly softens machine vibrations for operator comfort. Electronic pilot control levers with F-N-R switch are seat-mounted for convenience.

The KOMTRAX Plus telematics system and monitor provides key machine metrics, including KDPF status and DEF level data, fuel consumption, plus performance information collected and sorted by operator ID.

The 7-in high-resolution monitor is full color and visible even in harsh light, the company claims. A separate, full-color rearview monitor comes standard and improves line-of-sight. This model is also the first to include an integrated load meter that is incorporated into the monitor and KOMTRAX, said Boebel. Data is available on the machine monitor and remotely via the web.

The WA600-8, along with every Komatsu Tier 4 Final construction-sized machine, is covered by the Komatsu CARE program for the first three years or 2000 hours. This program includes limited scheduled factory maintenance, a 50-point inspection at each service, and one complimentary KDPF exchange in the first five years. Select labor, fluids, and filters are also covered.