One point about Amsoil is that you could stretch your OCI out further. You are constantly changing your oil running 70,000 miles annually at 3000 mile intervals. With the right oil you could be reducing your maintenance costs and downtime.
Yes, just think: 70k / 3k = 24 oil changes per year. 70k / 10k = 7 changes per year. 70k / 15k = 5 oil changes per year.
Even at a fast oil change pace from start to finish, 24 changes/yr * 30 mins = 12 hours. 5 changes is 2.5 hours.
Let's estimate that Navi's business is very successful, and average a mere $200/hr in operation. The uptime increase alone is 9.5 hours * 200/hr, or $2000 per year, per vehicle simply for the time lost during maintenance. Now add the cost of 19 more oil changes, and 19 more oil filters... and the cost is in the neighborhood of $3000 per year, each. Not to even mention all of the waste oil and filters.
Further analysis: WM oils average ~$6/qt when purchased in bulk. HPL averages around $12/qt when purchased in smaller sizes. Let's also assume a $9 filter as well, regardless of brand.
WM oils: 24 oil changes * ($6/qt * 6qts) + 24 $9 filters = $1080 per year, plus 12 hours labor @ $200 = $2400. Bringing grand total for WM shelf stock to $3480 per year, per vehicle for just oil changes.
HPL oil: 5 oil changes * ($12/qt * 6 qts) + 5 $9 filters = $405 per year, plus 2.5 hours labor @ $200 = $500, bringing grand total to $905 per year, or
a $2575 savings per year, per vehicle. If operated like HPL's test fleet, we would have to include 2.5 quarts makeup oil to refill filters, and 10 more filters to respect their FCI of 5k. This would add another $124/yr to the HPL, leaving a mere $2k savings per vehicle.
Funny thing, I completely acknowledge that Navi is free to do what he wants and burn his money needlessly, but I laugh that a successful businessman is willing to ignore $2500/year increase per vehicle in his revenue. At 70k per year, he's not keeping them forever, so there's almost zero increased risk with the second plan.