91 octane, which is premium in my area, since day one (13 months / 7000 miles). I don't know that my 4.0L PF would have performed any worse on 87 octane, but for now, I just blow off the extra $3.00 per tank as good insurance against reduced performance.

Greybrick wrote:Hi OOvoid,

for the recommended fuel octane reference in the service manual download the above 2008 copy, then click on the MA-maintenance section, then go to page MA-10 for recommended fuel and fluids. A further reference will also take you to the 'General Information' section page GI-40 which further states that: Gasoline Engine, Use unleaded gasoline with an octane rating of at least 91 (RON), which is unleaded regular fuel in this part of the world.

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the PDF isn't working for me. only gives me 9 pages. i believe what you wrote is straight from that service manual PDF, but i'm confused as to why they would say to use Regular in that, but in my owners manual they suggest Premium?

This may be of interest to any who would like to use the Pathfinder recommended 87 AKI fuel in their truck;

http://en.wikipedia.org/wiki/Octane_rating

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SilverGhost wrote:I just blow off the extra $3.00 per tank as good insurance against reduced performance.

:thumbup:

I mix it up a little. I generally put in atleast 89, but don't feel bad putting in 87. Generally if I put in 87, I put in 93 the next time. I almost never run below 1/2 a tank. 38000 miles on my '06 w/ a fair amount of towing, no engine problems.

Not long after we got our Pathy we did a switch to regular and mid-grade...this was about the time of Katrina when prices spiked really high...well what we noticed is that on hot days (and we get HOT days) we would actually get worse gas mileage...so back to premium it was...also when we got down to it...the difference is only a couple of bucks a tank....

For what its worth:

I used to own a Titan before my current Pathfinder, and this debate raged on the Titan forums as well. With all that debate, here is what we found out:

The V8 in the Titans and Pathfinders has adaptive timing which can adjust to different levels of fuel. This means there may be less HP and TQ with regular fuel, but unless you are towing heavy loads or at high altitudes you shouldn't feel much of a difference. (Seat of the pants feelings are only reliable if there is a 5-8% change in performance minimum, that is a huge difference of power in the V8s which is unlikely from regular to premium fuel) Also, no one on the Titan forums ever saw a difference in mileage between the two fuels with the V8s unless they were towing heavy loads.

All that said, I have run both regular and premium in my V6, and the same results have been found. I can not tell any difference in performance or mileage. This doesn't mean that there is not a difference, it just means that I can not physically feel any difference. There probably is a slight difference due to the chemical differences in the gas, but not enough to notice under light loads, towing 6,000 lb loads may be a different story though...

i put in the premiem and cant forget the lucas octane booster

I voted "other" because I put 98 RON fuel here in france...
wich is something like the us Super Unleaded...I guess.

anyway, I don't use much fuel but rather LPG wich typically have octane ratings of 110 or significantly higher.

Been using 87 for 3 years and 46K. Thats is unless I'm towing for long distances (300-750miles a clip) then I'll use 93. I really haven't noticed any difference regarding fuel eco between the two. I'll save the loot from the price difference and put it to magnaflow 50.

I know this is some serious thread necromancy but I'll do it anyway

Have the V6.

In my area 93 is available so that gives me an extra "cushion" if I ever mix any lesser fuel in.
Around town I stick to 93, my drive to work is short and it does not affect the pocket book but its urban driving so its abit harder on the engine.

When I go on a longer trip on interstate crusing which is a light requirement on the engine I usually use midrange.. or if midrange and premium are a big diff over regular I may mix in as much as half a tank of 87.. but thats unusual.. (and usually reserved for driving at altitude which lowers the Octane requirement even further )

Then look for a place where premium isnt excessively priced to top it off after running the tank down a bit.
I usually calculate in my head where I am in octane mix in the tank but never let it fall below a tad better than midrange..
(half a tank of 89 mixed with half a tank of 93 =90 Octane)

I'll add to the thread necromancy...

@palmerwmd - we have 93 over here in Texas as well which is nice along with a few 85 MPH speed limits With that said, I add A LOT of highway miles (320mi 1 way) driving from Austin to my parents place in Deep South TX. In fact, I'm heading down there for the weekend. What's your highway mileage like running the higher octane? I can generally make the trip averaging ~18mpg (according to the trip computer) with 87 octane leaving me about a 1/4 tank when I arrive.

I suppose I can try it anyway, but just curious what your take was.

underworld1001 wrote:I'll add to the thread necromancy...

@palmerwmd - we have 93 over here in Texas as well which is nice along with a few 85 MPH speed limits With that said, I add A LOT of highway miles (320mi 1 way) driving from Austin to my parents place in Deep South TX. In fact, I'm heading down there for the weekend. What's your highway mileage like running the higher octane? I can generally make the trip averaging ~18mpg (according to the trip computer) with 87 octane leaving me about a 1/4 tank when I arrive.

I suppose I can try it anyway, but just curious what your take was.

I can do 20 mpg with 93 Octane.
This is with no attempts to hypermile but no extreme passing maneuvers etc..
If I exercise a lot of care ( moderate speed+ gentle accel) I can go to 22 mpg for a long hiway trip.

palmerwmd wrote:

underworld1001 wrote:I'll add to the thread necromancy...

@palmerwmd - we have 93 over here in Texas as well which is nice along with a few 85 MPH speed limits With that said, I add A LOT of highway miles (320mi 1 way) driving from Austin to my parents place in Deep South TX. In fact, I'm heading down there for the weekend. What's your highway mileage like running the higher octane? I can generally make the trip averaging ~18mpg (according to the trip computer) with 87 octane leaving me about a 1/4 tank when I arrive.

I suppose I can try it anyway, but just curious what your take was.

I can do 20 mpg with 93 Octane.
This is with no attempts to hypermile but no extreme passing maneuvers etc..
If I exercise a lot of care ( moderate speed+ gentle accel) I can go to 22 mpg for a long hiway trip.

Just from my recent trip two weeks ago. From NJ to Myrtle Beach, SC (~1500miles). I averaged 20mpg on 87 octane. Speeds are 80% 75mph or more. I even hit some traffic on VA and MD (Washington area) coming back home.