Volvo VNL 2018 I-Shift Improved Transmisions v2.1

Update:

v2.1

- added non-retarder variants.

This mod based on real spec adds rear axle ratios for Volvo VNL 2018 with I-Shift transmisions:

- Meritor S-Fast -- 2,28;

- Meritor FUELite+ -- 2,47;

- Volvo XE -- 2,64;

- Volvo XE Fleet -- 2,85;

- Meritor FUELite -- 3,06;

- added retarder on default I-Shift transmisions;

- mp_mod_optional: true.