I don't want to start any crap, because I'm sure that I will be needing your collective help with my son's "new" Ranger, but I wanted to mention some of my observations regarding the use of premium fuel.
If anyone "accidentally" put regular in our 96 Acura RL, the car figures it out (maybe some kind of detonation sensor) and retards the timing - then I notice that the car has less pep and gets a couple of miles per gallon less than normal.
The same thing happens with an 06 BMW that we have and an 05 Infiniti that we had. So I'm convinced that there is some way that the "computer" knows when the fuel has a lower level of octane and "de-tunes" the car to prevent detonation.
I am currently driving a 6 cyl Tacoma that calls for regular gas. When I first took delivery, it must have had some stale and cheap gas because it performed poorly and made extra noise. When I put fresh fuel in it, it ran like a champ. Whenever I gas up with premium, the Tacoma has noticably more pep, is slightly more quiet and runs more smoothly - oh yeah, and gets a couple extra miles per gallon.
I think that the same thing is happening here that I mentioned with the other vehicles - but the manufacturer chose to rate the mpgs and vehicle for regular fuel. When I add premium, it sure seems like the "computer" recognises the extra octane and slightly advances the timing for a little extra pep and mileage.
We just got the Ranger 2.3L so I don't know much about the effects of premium on the performance or mileage - that's why I'm reading this thread.
Thanks for having this forum, I'm reading all 195 threads tonight so I can help my son deal with some of the issues that might arise with his "new" truck.
RC