Caterpillar: E Series meets new emissions regs

The five new compact-radius Cat E Series Mini Hydraulic Excavators — 303.5E CR, 304E CR, 305E CR, 305.5E CR and 308E CR SB — all use new engines that meet Stage IIIB /Tier 4 Interim emissions regulations and incorporate new features such as the Complete Operation, Maintenance, Performance, And Security System (COMPASS) control panel, standard high-ambient cooling package, more efficient auxiliary hydraulics, and redesigned control layout. Built into the COMPASS monitor are an anti-theft system, which requires a five-digit alphanumeric password to start the machine, and an Economy Mode feature (3.5- to 5.5-ton machines), which Cat says can potentially lower fuel use up to 20 percent by adjusting engine speed. An automatic engine-idle system drops engine rpm to idle after four seconds of inactivity.

A continuous-flow feature for auxiliary hydraulics, which maintains selected flow without operator intervention, is also available through COMPASS.

Additional refinements for the five E Series models include a standard high-ambient cooling package, electronic fuel-pump-priming system, a four-post canopy (3.5- to 5.5-ton machines), new ergonomic joysticks, and relocation of a number of controls such as the two-speed travel switch to the blade lever, secondary auxiliary hydraulic engagement to the left joystick, and manual pattern changer from the floor to the COMPASS monitor.

All new E Series machines use an end-damping system in both the boom and stick cylinders to reduce shock loads and to reduce material spillage. E Series sticks are thumb-ready, with brackets welded in place and relief valves already built into the main valve. The 308E CR SB will be available only in a swing boom configuration.

Machine Specifications
303.5E CR 304E CR 305E CR 305.5E CR 308E CR SB
Cat Engine C1.8 C2.4 C2.4 C2.4 C3.3
Power, kW (hp) 24 (32) 31 (42) 31 (42) 34 (46) 50 (67)
Op. Wt, kg (lb) 3,563 (7,855) 3,854 (8,496) 4 974 (10,965) 5,270 (11,618) 8,210 (18.099)
Dig Depth, mm (in) 3,200 (126) 3,454 (136) 3,683 (145) 3,886 (153) 4,724 (186)