Division 5.3 Calculation of Lref

L_ref = L_{anchor_K} + Slope_K * (n_{ref_K – nanchor_K})/1 000

L_ref shall be less than or equal to 76 dB(A).

For vehicles fitted with a manual gear box having more than four forward gears and equipped with an engine developing a rated maximum net power greater than 140 kW and having a rated maximum net power/maximum-mass ratio greater than 75 kW/t, L_ref shall be less than or equal to 79 dB(A).

For vehicles fitted with an automatic gear box having more than four forward gears and equipped with an engine developing a rated maximum net power greater than 140 kW and having a rated maximum net power/maximum-mass ratio greater than 75 kW/t, L_ref shall be less than or equal to 78 dB(A).