The department where I serve uses what most governmental agencies use: the lowest cost bidder.
I was somewhat disappointed when I found out that our department has for years been using bulk drum Wolfshead 10w-40 HD, I think in SJ forumation. Not because it's a bad oil; although I don't consider it "outstanding" by any means.
The issue is that they use this fleet oil in all gas powered equipment at the county highway garage, where the CVPIs (Crown Vic Police Interceptors) get their routine service. All vehciles get 5k mile OCIs on that regular basis. They don't care that Ford specs (previously 5w-30) a 5w-20 SM for the 4.6L. They use this stuff everywhere; in the light duty trucks, in the CVPIs, in the Impala run-a-bout cars, in the lawn tractors; all the 4 stroke engines get this stuff. I asked the foreman in the garage about it, and his comment was to the effect of "Thicker is better."; that was the extent of his knowledge, and he is in charge!
Trust me when I say this realtively young guy is "ol' skool" in his shade-tree mentality concerning lubricants in general. There is no such thing as ploy-urea, lithium, moly grease; it's all just "grease". "Oil is oil". DexIII/Merc equivlants go in everything tranny related. Yikes!
On one hand, it's disconcerting that they won't follow OEM recommendations. On the other hand, we put around 100k miles on a CVPI and then trade it in. They get pounded on, as you can imagine. And yet, they continue to run with no problems. All the vehicles are serviced with this fluid, and in general there are no mechanical issues to report relative to oil. Perhaps an engine teardown would reveal something, but I can assure you that there's no budget to cover that endeavor, simply for "infomation retreival".
If there's anything to learn from this, perhaps it's that committment to service is more important than fluid choice. The highway department is religious about OCI's in all respects. The fluids are changed at 5k miles for engine oil, 20k miles for tranny oil, diff fluid at 50k. Greased at 10k miles.
Kind of puts the anal-retentive BITOG experience in a perspective, don't you think?