I've been using Hot Shot's Secret TBN Booster in my diesel truck for about 15,000 miles now, and I can confidently say it's transformed my oil change routine. The difference isn't just theoretical - I actually hear my engine running quieter, like it's humming instead of growling.

What surprised me most was how it smoothed out my older engine. I expected some protection benefits, but didn't anticipate that 'sewing machine' smoothness other reviewers mentioned until I experienced it myself during cold morning starts.

The real magic shows in my oil analysis reports. Where I used to change oil every 5,000 miles religiously, I'm now comfortably stretching to 10,000 miles while maintaining excellent TBN numbers. That's not just saving money - it's peace of mind knowing my engine internals are properly protected.

I add this with every oil change now (Rotella T6 + this booster), and the combination gives this velvety responsiveness when accelerating that makes driving feel premium. For anyone doing extended drain intervals or just wanting maximum engine protection, this bottle absolutely earns its keep in my maintenance routine.