KOMATSU PC55MR-5: What Buyers Need to Know

Quick answer: The Komatsu PC55MR-5 is a 5.5-ton conventional-tail-swing mini excavator built for tight urban jobsites. It delivers 38.6 hp, a 13,164 lb operating weight, and 12,894 lb of bucket digging force — making it a proven choice for contractors who need compact performance without sacrificing digging power.

The PC55MR-5 sits in a competitive weight class. At 5.5 tons, it's heavier than a micro excavator but lighter than a mid-size machine — which means it hauls efficiently, fits through restricted access points, and still moves serious dirt. Before you buy or rent one, know exactly what you're getting.

What Are the Key Specs of the Komatsu PC55MR-5?

Engine: Komatsu SAA4D95LE-6, 38.6 hp (28.8 kW). Operating weight: 13,164 lb. Max digging depth: 11 ft 4 in. Bucket digging force: 12,894 lb. Arm digging force: 8,384 lb. Max reach at ground level: 18 ft 4 in.

The tail swing on the PC55MR-5 is conventional — not zero-swing. That distinction matters on confined urban sites or near structures. If your work consistently puts you within arm's reach of walls or fences, price out the zero-tail-swing alternative before committing.

What Jobs Is the PC55MR-5 Built For?

This machine earns its keep in utility trenching, landscaping, foundation work, and demolition prep. The 11-foot-plus digging depth handles most residential and light commercial utility installations without a second machine. The Komatsu CLSS (Closed-center Load Sensing System) hydraulics give you smooth, proportional control — useful when you're grading finish work or placing pipe precisely.

One feature worth noting: the PC55MR-5 runs Komatsu's auto-idle and auto-shutdown systems. Fuel costs are real operating costs. A machine that manages idle time automatically is worth more over a 1,000-hour season than its sticker price suggests.

What Should You Check Before Buying a Used PC55MR-5?

Hours are a starting point, not the whole story. A unit under 3,000 hours with no service records is a bigger risk than a 5,000-hour machine with a complete dealer maintenance binder. Ask for the binder. If there isn't one, price accordingly.

Four components to inspect before you commit:

• Undercarriage: Measure track wear. Replacement runs $8,000–$15,000 depending on configuration. Don't absorb that cost silently in the purchase price.
• Hydraulic lines and cylinders: Look for seeping seals and cracked hoses, especially near the arm and boom pins.
• Bucket pins and bushings: Excessive play here signals deferred maintenance across the machine.
• Cab and controls: Run every function through full range. Hesitation or drift in the auxiliary circuit points to a worn hydraulic pump.

The fastest way to overpay is to skip the pre-purchase inspection. Hire an independent mechanic for $200–$400. That fee has saved buyers tens of thousands.

Is the Komatsu PC55MR-5 a Good Value Against Competitors?

In the 5–6 ton class, the PC55MR-5 competes directly with the Kubota KX057-5, Bobcat E55, and Caterpillar 305.5E2 CR. The Komatsu wins on digging force and hydraulic refinement. The Cat 305.5E2 offers a true compact radius swing — a meaningful advantage in tight quarters. The Bobcat E55 typically comes in at a lower used price point.

Choose the PC55MR-5 if hydraulic performance and Komatsu's dealer support network matter more than minimum swing radius. Choose the Cat if the jobsite geometry demands it.

Frequently Asked Questions About the Komatsu PC55MR-5

What is the operating weight of the Komatsu PC55MR-5?
13,164 lb (5,972 kg) in standard configuration. Weight varies slightly with attachment and blade options.

How deep can the PC55MR-5 dig?
Maximum digging depth is 11 ft 4 in (3,460 mm) — sufficient for most residential utility and foundation applications.

Is the PC55MR-5 a zero-tail-swing excavator?
No. The PC55MR-5 is a conventional-tail-swing machine. The rear of the machine extends beyond the track width during rotation. For zero-tail-swing, look at the Komatsu PC55MR-3 ZTS variant or competitor models.

What engine does the PC55MR-5 use?
The Komatsu SAA4D95LE-6, a 4-cylinder diesel producing 38.6 hp. It meets Tier 4 Final emissions standards.

What is a fair used price for a PC55MR-5?
Used pricing varies significantly by hours, condition, and region. Units with 2,000–4,000 hours and documented service history typically trade between $35,000 and $55,000. High-hour machines with deferred maintenance sell lower — but budget for undercarriage and hydraulic work before assuming a low price is a good deal.

Start with the Inspection, Not the Price

The PC55MR-5 is a proven machine. Thousands are working jobsites across North America, and parts availability through the Komatsu dealer network is strong. What separates a smart purchase from an expensive one is due diligence — service records, a mechanical inspection, and undercarriage measurement before any money changes hands. Know your numbers before you negotiate.