You noticed.
Its been the same for 50 years.
Patrolling is expensive. You pay for fuel and maintenance.
The PN runs on a shoestring and always has.
Your answer is most interesting. Yes, of course I notice. They are just under my nose.
But the maintenance and the salaries have to be paid anyway... well maybe the engine has to be in better shape for real patrols. That leaves the fuel....