I unlocked my Test menu in my cluster.
Changed the oil Shell Rotella T6 5W-40 and Mann filter
After completing a 2200 mile round trip up to Indiana (half of it pulling a 5x8 U-Haul trailer with 2500# of granite slabs) I can see that my thermostat has been stuck open for quite some time. I sure paid the fuel mileage penalty ARGHHHH!
Torque app says about 188*F temp in cruise. Unlocked cluster test #7 shows about 84*C in around town with OAT of ~35*C.
Well thankfully it was not stuck closed! And I just changed it maybe 15K miles ago when I did all the hoses, belts and tensioners. I'm getting a Behr thermostat unit this time
Sure hate to be in those 210*F temps but the open loop fuel economy sucks!
Mike