from my experience with the JDM tune the tune did not touch OFF ROAD MODE except for the advanced timing and adjusted A/F ratios. The throttle response and shift mapping seemed completely unchanged from stock. The only thing that I swear is my truck did shift harder in all 3 computer modes. So in other words, the engine tuning shouldn't really change and should carry over to off road mode and t/h mode. All those modes really do is change the way the truck shifts besides the separate functions for stability, ABS and TC with the offroad mode.
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