I have a new Altima (03)with the 3.5. The gas filler door says use premium fuel. The manual is very confusing on what octane to use....87 or 92 What do you guys use with this engine?
So, what does your manual say? I don't have a Nissan Altima, but I understand it gets a lot of horsepower out of that 3.5 L.
Is there any mention of altitude? Above 5000 ft, the octane requirement reduces.
If Nissan put a sticker inside the fuel door stating you should use premium, then that is what you should do. The owners manuals are a little generic, and will have specs for all of the different engines, and accessory set-ups.
The premium fuel actually burns slower than 87, so it allows for an earlier spark and a higher compression ratio, which result in more torque. While 87 won't ping, at least not much, that's because the knock sensor would detect pinging long before you hear it and retard the ignition timing in order to reduce/prevent it.