Fitment Information Nissan Altima Coupe L33 3.5L/2.5L (2008, 2009, 2010, 2011, 2012, 2013) Emissions Compliance This is an axle-back exhaust and does not alter, replace, or modify any emissions equipment. Specs & Features Axle Back Exhaust System Stainless Steel Construction Polished Stainless Tips, End Pipes and Mufflers Increase of Horsepower and Torque Mild at Idle/Cruising - Aggressive Note Under Throttle WHP Increase (horsepower to the wheels) Gain Torque Mild note at idle; Cruising- Aggressive note under throttle Compliments the factory exhaust cut out nicely High quality system that is easier on your passengers' ears than a full cat-back system. Perfect solution for those who value a more luxurious and quiet cabin feel along with enhanced sound. Delivers an aggressive look that matches the enhanced exhaust note. Limited Lifetime Warranty when purchased through Redline360 (authorized dealer) STILLEN's Nissan Altima Exhaust Systems are built for power constructed of Stainless Steel for best sound and performance increase. The power capacity is felt across the power band with the growing beneficial gains on the top end of the tachometer. Mileage per gallon boosts advantages can be expected as you cruise at steady speeds during highway travel. The improved airflow created by additional diameter of the 2.5 mandrel bent exhaust piping is verified by the significant DYNO HP increase. Adding the STILLEN exhaust to your Nissan Altima is a must, waking up the L33 Altima, freeing it from the factory restrictive and inefficient small exhaust tubing. With the engineering team ensuring a proper but also perfect fitment this cat-back exhaust is second to none. The free flowing performance mufflers themselves are built out of stainless steel for life longevity and power achievements. Finishing the exit end of the cat back exhaust are dual polished STILLEN engraved muffler tips, making this a true STILLEN authentic exhaust that can be noticed the rear valance cut outs.