bigbro9395 wrote:I have approx 11000 miles on my 2008 Pathfinder and have been using regular, unleaded 87 octane. Should I change to premium? I have run into several, similar questions, with various answers.
I've been using 87 octane then switched to 91 octane for a few weeks. I have not noticed any difference in mileage. I do both city and highway driving to and from work, mainly, with little traffic in the morning. During the summer, mileage is at it's peak. When fall comes, mileage will go down, based on outside temperature. The Californians and south will get great mileage, while the north will not fair as well.
So yeah, in my opinion, higher octane won't give you better mileage. The 4.0L Pathfinder's compression ratio is less than 10:1, therefore 87 octane is fine. If it were higher, then a higher octane fuel is needed as you'll hear a knocking/pinging sound coming from the engine.
Try it for month, if you want, and tell us your experience.