2019 RST4x4 5.3. 24,000 to date no issues. I am in the minority in that I don't mind the DFM my lifetime mpg is over 20 mpg. The system seems pretty seamless the microsecond delay to full power is not an issue for me. 2019 being the first year with the new DFM I purchased the extended warranty for 7 years if it breaks I'll get it fixed. In the meantime I will be out enjoying this technical marvel to its fullest! I say technical marvel because I grew up riding and driving in 70's and 80's trucks these new T-1's are complex machines that are powerful and capable get out and enjoy!