Caterpillar Performance Handbook, January 2017, SEBD0351-47

Fuel Consumption 8

Owning & Operating Costs

To estimate hourly fuel cost, select the load factor based on application and find hourly consumption. Then: Hourly consumption × Local Unit Price of Fuel = Hourly Fuel Cost When using these tables, keep in mind the many vari- ables which can affect fuel consumption. Two operators of different temperament or attitude operating identical machines side by side in the same material can have as much as 10-12% difference in their consumption rates. Actual results may vary from the ranges shown because they are created to cover a wide spectrum of operating conditions. Your Cat dealer representative can help select the most reasonable estimate for your specific situation; we suggest you call on him. Keep in mind also that a fuel consumption study mea- sured over a short period of operation will give higher fuel consumption than shown here because: (1) the study will be at 100% productivity, without breaks or idle time, and (2) the operators will know they’re being measured and therefore may not use their normal operating techniques. On the other hand, these tables allow for “normal” inef- ficiencies in the working cycle and will more closely relate to “normal” day to day operation.

ESTIMATING OPERATING COSTS (Line Items 8 through 13)

8-13

8

FUEL CONSUMPTION (Line Item 8)

Actual fuel consumption should be measured in the field. However, if no opportunity exists to do this, con- sumption can be estimated when the machine applica- tion is known. Application determines engine load factor and engine fuel consumption. Engine load factor refers to the instantaneous loading of the engine relative to its maxi- mum capability. An engine continuously producing full rated horsepower is operating at a load factor of 100%. Earthmoving machines may reach a 100% load factor intermittently, but seldomoperate at this level for extended periods of time. Periods spent at idle, dozer and pusher travel in reverse, haul units traveling empty, close maneu- vering at part throttle and operating downhill are exam- ples of conditions which reduce load factor. The following tables provide hourly fuel consumption estimates at various load factors. Engine load factors are to be used as a general guide and will vary by model and application. Since machine uses vary, application guides are also provided to aid in estimating load factor.

25-8 Edition 47