"Pressure at the fuel injectors has increased from 15,000 psi a few years ago to nearly 30,000 psi on new engines," says Pete Brown of Caterpillar''s engine applications group. "To get these higher pressures, fuel pumps are built to closer tolerances. Dirt in the fuel is like sandpaper, and it will definitely cause greater wear."To meet the challenge, Cat''s newest engines are equipped with increased water-sensing and fuel-filtering capabilities as well as a filter on the fuel tank breather. Primary fuel filters, once designed to remove 150-micron particles, are now rated for 10 microns. Secondary filters, once sized to remove 10-micron particles, are now rated for 2 microns. And the new high-efficiency filters can remove up to 99% of particles above those rated sizes compared to the 50% efficiency of older nominal filters. Filter improvements are also available for storage tanks. "Tank filters are typically rated at 10 microns nominal, so they take out 50% of particles greater than 10 microns in size. Tank filters with higher efficiencies, ratings down to 2 microns and water-absorbing capabilities, are now available," says Gall.

Most augers dig about 3 ft. deep, but for deeper holes, ask for an extension rod (Photo 5), usually for no extra fee. Deeper holes are typically required for footings for decks or other structures attached to houses located in very cold climates where frost depths exceed 3 ft. An extension rod will get you down as far as 4 ft.After you''ve made your choices, ask the clerk to check the gas and engine oil levels, and demonstrate starting and operating procedures. Also make sure you have all of the shear pins (Photo 5) that lock extension rods and augers to the power head. By the way, you''re usually responsible for furnishing your own fuel unless the unit you''re renting is a two-stroke model that requires premixed fuel.

Speaking of saving amperage, consider some of the new warning light packages using light-emitting diode units. You can significantly reduce your amperage requirements compared to a halogen or strobe lighting package. Be prepared to pay more, but the payoff is that an LED will last for 100,000 hours - that''s the equivalent of more than 11 years of continuous operation.Power needsGenerators, too, have come a long way since the first light-duty rescue trucks were built. Built-in or portable generators still are an option, but the size, weight and cooling requirements should be considered in design and layout.

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