Working in law enforcement for an agency that has over 1800 sworn pursuit vehicles, and an additional 400 admin vehicles, in Florida, I call [censored].
None of our vehicles aside from some newer Fords have an hour counter anywhere in the OBDII system or ECU. And, I can promise you that nobody is scanning either of those thigns when my vehicle goes in for PM service (I've had a piece of scotch tape over the OBDII port for 30k miles now).
Speaking specifically to our old fleet which was composed mostly of 2008-2013 Chevrolet Impala PPVs (2008-2010's with the 3.9 liter 3900 variable displacement OHV V6 and 2011's on with the 3.6 PHC high feature V6).
My 2008 Impala got Formula Shell 5w-30 Conventional at Jiffy Lube with a horrible knock-off generic filter. My vehicle ran 5000 miles before being changed. To be clear, an average shift included responding to at least 4 emergency calls for service. Each of those entailed at least 8 to 10 WOT accelerations from a standstill up to past 100mph, followed immediately by threshold braking to a complete stop. Then, the cars are either left to idle for hours (to keep our computers from shutting off due to the heat of the cabin or we have a badguy inside) OR they are shut off immediately after arriving at the call. Some genius also thought it would be a good idea to run K&N air filters fleet-wide. Yay!
Units covered an average of 80 miles per shift. Divide by 5000 miles and that's 62.5 shifts, or 500-625 WOT drag races past 100mph per oil change. Minimum.
This issue is compounded by the fact that on both the 3900 and High feature V6, heat was unable to be effectively removed from the engine compartment and melted wiring harnesses, dead batteries, and even deformed polymer intake manifolds were commonplace. The AC routinely shut off after a pursuit if speeds did not exceed 30 mph.
Idling was essentially the entire shift. So, 62.5 * 11.5 hours (not counting overtime or off duty traffic details). So, a conservative estimate of 718.75 hours on each run. K9 vehicles have to run every hour of every day that the dog is inside the vehicle (again, Florida heat), and they get hammered as well (K9 vehicles are all Chevy Tahoe PPVs with the 5.3). Also, the impala batteries would be completely dead after 7 days of sitting. So parasitic losses were high, along with the massive electrical loads present during use (and all had DRLs except mine where I pulled the fuse). Car radio, Car siren and light controller box, 180 watt laptop charger, portable radio charger, flashlight charger, cellphone charger, car stereo playing, etc.
By 118k miles on my old Impala, I was burning a quart of oil every three shifts. I refilled with Mobil-1 10w-30 HM, and was religious about checking all my fluids, but it didn't make much difference. All pursuit vehicles are kept to 140k miles. All admin vehicles until 170k.
So, For Polk County (not far from me, though VASTLY smaller in manpower), the decision may have worked out. Even with full syn 10w-30 oil with a fram ultra filter, there's little chance we could do the same on our vehicles.
