[Lazarus]

Here's an interesting tibit.

In a survey conducted by Valvoline, sixty-percent of ASE certified Master Automobile technicians questioned said that a vehicle's oil should be changed every 3,000 miles. Twenty-nine percent said between 3,000-5,000 miles is acceptable and just two percent voted that between 5,000-10,000 miles is okay

They are the ones that help keep it going.

In Europe the interval is over 10k.

There was a hypermiler on clean MPG that used Dino and oil samples to run over 10 k intervals with no problem.