The C7 was only built in a 330 or 360HP version for RVs. After 07 they were all 360s due to the added equipment for emissions and ran hot so CAT, not wanting to spend millions trying to cool ddown engines quit the Over-the Road business. CATs in line 6s were the best engines ever built as they were bulldozer engines and the 3406 was built ot run 1 million miles b/n Overhaul.
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.
At one time they actually had horsepower ratings: 210, 230, 250, 275, 300, 330, 350 and 360 hp.
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. After 2007, 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.