Your point is valid, and I somewhat agree. But you also have to consider what having the higher performance engine costs as well. For example, the HEMI option in my Jeep, over the standard Penstar V-6 was an additional $3200.00 and change.
So it seems pointless to pay that much more for a high performance V-8, only to turn around and pinch pennies by running it on 87. Which it will, but as the manual states, "with a reduced level of performance".
Most all of the newer engines are set up this way. And many are running very high compression. My Toyota runs a 13:1 compression. Yeah, it's an Atkinson Cycle, so it is capable of running a lot less. But for best mileage and performance it still pays to run 91, or even 93. Especially if I'm getting over 40 MPG doing it.
The 5.7 Hemi runs 10.5:1. So in order to achieve the best performance and mileage, running at least 91 is the way to go. Also to be considered in my case with being retired, is that I drive very little. So the slightly additional fuel cost isn't really much of an issue.
If I had a 50 mile commute each way daily, then it might be a different story. But in all honesty if I did, I most likely wouldn't have purchased the V-8 in the first place. (Although the Penstar V-6 isn't the greatest when it comes to fuel economy).
