A symmetric twin ram air intake system reduces airflow resistance by 18% and functionally increases horsepower while driving. For example, a three hp increase is achieved at 60 miles per hour versus the previous generation. The dual exhaust system features equal length exhaust manifolds and low muffler exhaust pressure (25% less than the first generation G35) to help improve engine breathing. Both are tuned to create a performance exhaust note, helping enhance driving pleasure. Other new-generation engine enhancements included the addition of standard variable exhaust cam timing (eCVTCS), a higher red line (increased from 6,600 rpm to 7,600 rpm) and higher compression ratio (10.6:1 versus the previous 10.3:1), asymmetric piston skirts, twin knock sensors, improved coolant flow and new Iridium spark plugs.