The decibel data provided is for reference purposes only. This information is provided for comparison between our different product offerings for a given application. This gives some gauge of loudness of one product versus another, and may aid in determining what product is best suited for individual customers.
Vehicles used to gather the data are generally stock. No aftermarket or performance: intake kits, additional exhaust components, engine tuning, no missing interior components but some do have aftermarket wheels/ tires, suspension components, aero parts, etc... The decibel reader does pick up some road noise, tire noise, and other ambient noises. We try our best to gather accurate data so our customers can make informed decisions when considering our products. Again, the purpose of this data is for reference material.
We are using a EXTECH, model 407750, digital sound level meter. In majority of vehicles, this device is securely placed in the center console cup holder.
All windows are closed, and climate control system is set to a minimum as to not affect the results.
Cold Start - taken when the engine is cold like during morning start up where the idle RPM is higher automatically increased for a short period of time to aid in the engine warm up process.
Idle - taken after the engine has fully warned to normal operating temperature
55mph - taken while holding steady speed on level ground. Usually taken with cruise control engaged.
65mph - taken while holding steady speed on level ground. Usually taken with cruise control engaged.
75mph - taken while holding steady speed on level ground. Usually taken with cruise control engaged.
Max at Free Rev - this is taken while stationary, and the engine is revved to just under RPM limiter. Note: some vehicles limit free rev well below redline.
NOTE: The sound level meter usually reads around 34 dB when placed in the vehicle, windows up, occupants still and silent, with the engine OFF.