This mod contains the X15 series engines produced since 2016, replacing the ISX series to meet EPA specifications. It contains the following engines, in the Stock and Delete Straight Pipes variants. Efficiency -485 HP -500 HP Efficiency ADEPT -485 HP -500 HP Performance -550 HP -600 HP Performance ADEPT -550 HP -600 HP Delete Straight Pipes -485 HP -500 HP -550 HP -600 HP It contains the following engines, in the Stock and Delete Straight Pipes variants: Freightliner -Cascadia International -HX520H (Harven) -Lonestar -LT Kenworth -T680 -T880 (FrankPeru) -W900 -W990 (Harven/FrankPeru) Peterbilt -389 -579 Volvo -VNL -VNL 2018 Western Star -49X -57X -5700XE Updates v 1.1 -Curvature adjustments in the turbo in Straight Pipes variant. -Added Volvo VNL 2018 (SCS)