Specifications of a Caterpillar C-7

by Tim Plaehn

From 2003 to 2009, the Cat C7 was Caterpillar's engine offering for medium duty class trucks. Medium duty trucks from GMC, Ford, Paccar and Freightliner could be purchased with the C7 as an engine option. Medium duty trucks cover a gross vehicle weight range of 18,000 to 33,000 lbs, have a single drive axle and are typically box trucks, flatbed trucks and tow trucks.


The Cat C7 replaced the model 3126E in the Catepillar on-road engine lineup to comply with the stricter diesel emission requirements which went into effect on January 1, 2004. Some truck manufacturers switched to the C7 as early as the 2003 model year. The engine was upgraded to meet the stricter emission requirements of January 1, 2007. Caterpillar stopped selling the C7 and the company's other on-highway truck engines at the end of 2009. The company elected not to try to meet the January 1, 2010 emission requirements.

General Description

The Cat C7 is an inline 6-cylinder diesel fueled engine. The displacement of the C7 is 7.2 liters, or 441 cubic inches. Engine features include turbo-charged air intake, common rail fuel injection system, full electronic control system and Caterpillar's ACERT fuel/air management system. Advanced emission solutions include a closed crankcase breather and a diesel particulate filter using Cat's proprietary regeneration system. The B50 life rating -- period to which 50 percent of engines had a major failure -- is 450,000 to 500,000 miles.

Dimensions and Capacities

The overall dimensions of a C7 engine are a length of 42.9 inches, width of 38.8 inches and height of 38.2 inches. The approximate dry weight is 1,425 lb. Engine oil capacity is 4.75 gallons or 6.75 gallons with the optional deep sump oil pan. Cooling system capacity -- engine only -- is 3.99 gallons. Cat C7 engines produced in 2007 or later require the use of ultra low sulphur diesel -- ULSD -- fuel.

Power Ratings

The Cat C7 was available with the following horsepower ratings: 210, 230, 250, 275, 300, 330, 350 and 360 hp. Torque ratings ranged from 520 up to 925 lb-ft. The 201, 230 and 250 hp. ratings were available in either a low torque or high torque option. The choice of torque options allowed different transmissions, which are rated by torque capacity, to be matched with the C7. The 330 through 360 horsepower ratings were only available in RV and firetruck applications.

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