Fuel for 2003 Pathfinder SE 3.5

[KptKrunch]

So, the recommendation is premium fuel. Would running 87 octane harm the engine at all, or just rob it's performance.

Here in Canada Husky offers 90 Octane for Regular price (just one point down from the 'premium' of 91). However, this fuel has up to 10% ethanol, and I found my 2000 Pathfinder would burn through that in no time.

As an example, on my 2000, a full tank would last me about 500 km's (give or take depending on the time of year and hwy driving).

With the '90' Ethanol, I'd be lucky to get 380 km's out of a tank (HUGE difference). Wondering if the '03 and the much nicer engine would gobble it up the same way or not.

Anyone in Canada with an '01 to '04 pathy have any experience with this?