What fuel grade do you fill up with?

[marlin29311]

for clarification since i don't have a pic of the manual...

"FUEL RECOMMENDATION

For 2.5L engineUse unleaded regular gasoline with an octanerating of at least 87 AKI (Anti-Knock Index) number(Research octane number 91).

For 3.5L engineNISSAN recommends the use of premium unleadedgasoline with an octane rating of at least91 AKI (Anti-Knock Index) number (Researchoctane number 96). If unleaded premium gasolineis not available, you may use unleaded regulargasoline with an octane rating of at least 87 AKInumber (Research octane number 91), but youmay notice a decrease in performance.

CAUTION- Using a fuel other than that specifiedcould adversely affect the emissioncontrol system, and may also affect thewarranty coverage"

from the manual, page 9-3

[fyrcomm]

hmm, I think almost all gas comes from American refineries. It is the oil that comes from imports but it is mostly refined in the United States.

hmm.. good point. that must be how they trick hardcore americans to go to their gas station.

... or maybe i'm just dumb and heard the guy wrong

[fyrcomm]

fyrcomm, you wouldn't happen to live in Mira Mesa would you? I only know of one Homeland Petroleum across the street from a Shell gas station here in San Diego.

Oh, and to stay on topic. I use regular.

yep i live in Mira Mesa...

and after reading everyone's responses to this thread, I'm just gonna stick with the 87 that i've been using for my 2.5

[CanadianCoupe]

Why would they tell 2.5 drivers to research 91 Octane?

You will not void your warranty if you use a higher octane, and you will not have negative effects. I just finished talking with a service department.

[maxentropy]

Exactly Marlin, thanks for the clarification. The manual states that there may be a decrease in performance but there is no statement that 87 should not be used or that it may be harmful to your vehicle.

87 octane simply has a higher chance to knock, or explode, than 91 or higher rated octanes.

Many high-performance engines are designed to operate with a high maximum compression and thus demand high-octane premium gasoline. A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.

If the engine begins to detonate (knock), that reduces power and efficiency for the reasons stated above. Many modern car engines feature a knock sensor – a small piezoelectric microphone which detects knock and then sends a signal to the engine control unit to retard the ignition timing. Retarding the ignition timing reduces the tendency to detonate, but also reduces power output and fuel efficiency.

So, if you fill up with 87 like myself and your car senses any knocking, it will retard the ignition timing, which reduces power. Like I previously stated, I have not noticed any decrease in power or mpg, so more than likely, the 87 octane I have been using from WaWa (huge gas station chain near me) is pretty damn good and hasn't been knocking much, if at all since my mpg is the same.

Hence, if this is true, those paying for 91 are only paying more and not benefiting anymore than my filling up with 87 octane.

[marlin29311]

They're not telling you to research it, it's called a "Research Octane Number." There is also a "Motor Octane Number," but you generally do not see this number printed in our manuals. The number that you see at the pump (87, 89, 93, etc) is an average of the RON and the MON (you'll see on the pump sticker "(R+M)/2"). Nissan is saying to use the 87 number listed on the pump with your 2.5, but in other countries, it could vary based upon how the octane is reported.

Max - I actually noticed a decrease in mpg's when using regular (87) in my 3.5, as compared to when i use 93. My mom also noticed that in her Infiniti with the VQ she got better mpg's when she put in 93 as well (I gave her the whole "it saves money in the long run" schpeil as seen in other threads). So I actually disagree with you on that - I am benefitting from using higher octane gas.

[maxentropy]

What was your mpg with 87 and mpg with the higher octane?

Mine were too close for difference... 93octane=~21.2mpg / 87octane=~20.6mpg

However, perhaps of note was the fact I was only running with the 93 during summer months and the 87 since (87 has seen winter and summer).

[marlin29311]

For comparison purposes, i used the same brand of gas, just for consistency. I used Shell 93 and Shell 87.

With 93 - I've been getting about 24.5 mpg's (and it's been slowly creeping up after SBD's grounding wires...)

With 87 - I got around 22

Numbers are caluclated based on gallons filled and miles driven (not the computer in the car, although that did reflect similar results as i've posted).

This is with similar driving loads. I (being type A about some things) did a monday to friday stint of driving to work each day, going to the gym, and visiting my g/f. Attempted to match driving styles, etc, to the best of my ability (can't predict dumbasses and red lights). Each week consisted of about 250 miles, and I asked the the attendent if I could fill the tank (NJ we get our gas pumped) for science purposes (the kid was like 18, he probably didn't know any better).

I can't confirm my mom's gains like this, but she said she did see an increase in her Infiniti I35 (has the VQ35DE).

What gas did you use during breakin, and have when have you changed your fuel types?

[maxentropy]

Mine were too close for difference... 93octane=~21.2mpg / 87octane=~20.6mpg

My math says: 21.2-20.6 = .6 more mpg * 20 gal tank = 12 extra miles per tank

12 miles = .566 gal of gas using 93octane * $3.919 a gal of 93octane here = $2.22 saved via extra mileage thanks to 93 octane.

20 gal tank filled with 93 octane = 20 gal * $3.919 = $78.3820 gal tank filled with 87 octane = 20 gal * $3.499 = $69.98

$78.38 - $69.98 = $8.40 saved by using 87 octane every tank fill.

Compare the $8.40 it costs more to fill your tank with 93 with the $2.22 saved via extra mpg with the 93... it makes more sense to use the 87 to save money-- unless you believe the $6.18 extra for 93octane (everytime you fill up) is getting you more power.

I'd rather pocket $6.

[marlin29311]

Daaaaaaamn your premium is so much higher than your regular - check out NJ where i live -

Regular 87 - $3.39Premium 93 - $3.63

I'll do this on a yearly basis -

Say you drive 12000 miles a year. At 22mpg, you need 545.45 gallons of gas, and at 3.39 a gallon, that's $1,849.09. At 24.5 mpg, you need 489.79 gallons of gas, and at 3.63 a gallon, that's $1,777.95. For me, that's a yearly savings of $71.14.

$71.14 = dinner with the girlfriend

[maxentropy]

Marlin- I used WAWA gas -- I think it's mostly from BP... decent quality stuff.

I used 93 for about 3 to 4 months after I bought my car and 87 since.

[maxentropy]

Daaaaaaamn your premium is so much higher than your regular - check out NJ where i live -

Regular 87 - $3.39Premium 93 - $3.63

I'll do this on a yearly basis -

Say you drive 12000 miles a year. At 22mpg, you need 545.45 gallons of gas, and at 3.39 a gallon, that's $1,849.09. At 24.5 mpg, you need 489.79 gallons of gas, and at 3.63 a gallon, that's $1,777.95. For me, that's a yearly savings of $71.14.

$71.14 = dinner with the girlfriend

Dude, that's insane. If the cost of premium would come down over here, it'd be very feasible to use it!!

[marlin29311]

Haha seriously dude, if i had my a/c while i was in school in philly, i would have hated using premium because of the price. Good thing i had my focus back then...

It's also possible that since you used premium during your rough breakin period, you might not have gotten better results. I would say give it a shot for a tank or two and see if anything changes. If it's better, then awesome! If not, ...i can mail you the check for $10?

[sonicbliss]

3.5 - the highest octane offered at whatever pump i happen to go to. here in DE i always fill up at the WAWA, as far as i know, its good gas.

[rjdmmfl1]

"as we cruise the metro on PREMIUM PETRO"... Tonight, Foxy Brown

3.5.. but when I had my 1.6L, 115hp , 1995 200sx, I would put premium in that bad boy also....

[BlackNWhite]

I always fill up at Chevron and I always fill up with 87.

Once I filled up with 91... and I used up that tank quicker than regular ol' 87.

[iiiskylll]

2.5 and usually fill up once a week at a Chevron or Shell with regular.

[domdada]

Daaaaaaamn your premium is so much higher than your regular - check out NJ where i live -

Regular 87 - $3.39Premium 93 - $3.63

I'll do this on a yearly basis -

Say you drive 12000 miles a year. At 22mpg, you need 545.45 gallons of gas, and at 3.39 a gallon, that's $1,849.09. At 24.5 mpg, you need 489.79 gallons of gas, and at 3.63 a gallon, that's $1,777.95. For me, that's a yearly savings of $71.14.

$71.14 = dinner with the girlfriend

Here's the prices we were selling gas at our gas station today.

Reg (87) - $3.49Mid (89) - $3.59Prem (93) - $3.69

It's the same price for cash and credit....and the price is 10cents difference between each grade 99.9% of the times. So for a 18 gallon fill, it's only a $3.60 difference between 87 and 93....so it's not biggie. Premium is my choice.

[vonivo]

Here's the prices we were selling gas at our gas station today.

Reg (87) - $3.49Mid (89) - $3.59Prem (93) - $3.69

It's the same price for cash and credit....and the price is 10cents difference between each grade 99.9% of the times. So for a 18 gallon fill, it's only a $3.60 difference between 87 and 93....so it's not biggie. Premium is my choice.

87 - 3.8989 - 4.0993 - 4.16

[CanadianCoupe]

I pay approx. $5.40/gallon for premium (we use litres so this is an approx. conversion), and in North Dakota which is 1 hour away its about they pay $3.60-3.70.

Worst part of all is North Dakota buys most their gas from us in Canada (we get screwed over on everything)

[maxentropy]

It's also possible that since you used premium during your rough breakin period, you might not have gotten better results. I would say give it a shot for a tank or two and see if anything changes. If it's better, then awesome! If not, ...i can mail you the check for $10?

I just may take you up on that

Seriously though, I should try it again for a month or two.

[NYblkcoupe]

I put in regular but i heard that if i put in super it would help. But that was from a kid who doesnt really know what he is talking about. So what should i be putting in.

2.5 by the way

[marlin29311]

...read the thread pal

2.5 = REGULAR3.5 = PREMIUM (if so possible)

[NYblkcoupe]

I know that, but if you say go to the track does it help if you put super into the 2.5?

[bembol]

Shell (91) V-Power.

[marlin29311]

I know that, but if you say go to the track does it help if you put super into the 2.5?

Putting anything other than 87 will do nothing for your 2.5. Unless you tune the engine to a higher compression ratio and such, the 2.5 will receive no benefit from higher grade gas.

[Khaled]

3.5SE - 98 octane

[Calgary35SE]

you must be using octane boost or something to get 98 octane.I got a 3.5SE and run mobil 1 oil with 94 Octane

O and another thing, I'm sick of americans bitching about the price of gas... 1 gallon contains 3.785 liters... at $3.39 a gallon it costs you 86 cents per liter!!!I pay 1.30 per liter...thats $4.92 a gallon

[Khaled]

I'm not using any octane boosters, the 98 octane is available at almost every gas station in the UAE.

98 octane is $1.7 per gallon here at the UAE if I'm not wrong. full tank is about $25.

[NYblkcoupe]

Putting anything other than 87 will do nothing for your 2.5. Unless you tune the engine to a higher compression ratio and such, the 2.5 will receive no benefit from higher grade gas.

That's what i thought