Not sure about all the tech conversations. Never had a problem with the DEF fluid. My new GMC has a level gauge full to empty instead of a percentage of use, which makes it much easier to know when to add fluid. Adding fluid is usually 3-5000 miles of use, or every oil change. My mileage has increased to 16-18mpg towing the Oliver. only have 3,000 miles on the truck. I expect this average to go higher once the engine breaks in. There also has been a big increase in tow capacity 18,000 vs 13,500 on my 2017 HD diesel I thought my 2017 highcountry Duramax was over kill. 🤯 The comfort and safety level of the GMC with the diesel is worth putting in DEF fluid not happy about the fuel prices, who is? Still couldn’t be more happier with the choice of a diesel tow vehicle. 😎 you could also import this to Trainman’s post on tow vehicles.