Caterpillar 308 CR Fixed Boom Mini Excavator Brings Reduced Tailswing, More Power To Its Weight Class

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Even with the Caterpillar 308 CR Fixed Boom’s optional 1,100-pound counterweight (an option not offered on its 307.5 predecessor), machine overhang with the cab rotated to the side is still reduced by 61%. (Photo courtesy of Caterpillar.)

Caterpillar's new addition to its 8.8-ton (8-metric-ton)-class mini excavator lineup is the Cat 308 CR Fixed Boom. It replaces the Cat 307.5 Fixed Boom with 25% more gross horsepower, greater lift capacity over the front and side, and a smaller working footprint. Its shorter tailswing radius facilitates work in tighter spaces for utility jobs, site prep, and residential construction.

The Cat 308 CR In A Nutshell

“We’ve continued the popular next-generation design features of stick steer, cruise control, Ease of Use technology-ready, and a comfortable pressurized and sealed cab in the new 308 CR Fixed Boom mini excavator,” says Greg Worley, Caterpillar market professional for mini excavators. “Plus, we’ve given this 8-ton-class machine a compact radius design, a slightly larger undercarriage for stability, and two counterweight options for even higher lift capacities than the 307.5. The new 308 delivers maximum power and performance in a mini-size excavator to work in a wide range of applications.”

Short Tailswing Radius

The “CR” in the 308’s model number stands for “compact radius,” meaning the rear of its upper structure doesn’t stick out as much when working to the side. Compared to the outgoing 307.5, the new 308 CR reduces machine overhang by 67% when equipped with the 550-pound (250-kilogram) counterweight package.

Even with the optional 1,100-lb (500-kg) counterweight (an option not offered on the 307.5) overhang is still reduced by 61%. This is a benefit when there’s a need to squeeze between structures, work along roadways, or operate in fenced-in residential backyards.

Cat 308 CR Dig & Reach Specs

In its long-stick configuration, the 308 CR posts a slight increase in digging depth to 185 inches (4,700  millimeters). It also improves upon maximum reach at 272 in. (6,900 mm). Importantly for contractors and fleet owners with existing attachments, pin sizing for the 308 CR remains the same as the 307.5.

Horsepower Gains

Caterpillar took a major step forward with the 308 CR’s 25% gross horsepower increase over the 307.5, aimed at improving performance with hydromechanical attachments. On a net power basis, its Cat C2.8 Turbo engine is rated at 69 HP (51.4 kilowatts). The diesel engine meets EPA Tier 4 Final and EU Stage V emissions standards. Its automatic idle and auto shutdown features add to the efficiency of a variable-displacement (smart) hydraulic pump to help keep operating costs in check.

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The Caterpillar 308 CR’s 25% gross horsepower increase over the 307.5 model improves its performance with hydromechanical attachments. (Photo courtesy of Caterpillar.)

Cat 308 CR Undercarriage & Stability

Caterpillar also augmented the 308 CR’s stability and lifting capability (especially over the side) with greater track width, undercarriage length, and machine weight. Track options include rubber belt, steel track, or steel track with rubber pads to suit surface conditions and jobsite requirements.

Cat 308 CR Technologies

To assist new and experienced operators alike, the 308 CR supports Cat Indicate and E-Fence, available from the factory or as field upgrade kits. Indicate offers basic grade guidance with visual and audible cues, while E-Fence adds motion constraints like E-Ceiling, E-Floor, and E-Wall to help operators avoid overhead hazards, protect underground utilities, and maintain safe working boundaries.

Caterpillar also highlights Laser Catcher site reference point technology and upgrade paths to Cat Grade Advanced 2D and Cat Grade 3D for more complex grading needs.