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2009 PF fuel requirement change

Posted: Wed Oct 08, 2008 10:19 am
by Gray
In the 2005 - 2008 owners manuals Nissan recommended use of 87 AKI gasoline and 91 AKI only for 'improved vehicle performance' but looking through the 2009 PF owners manual, page 9-3 I see Nissan is now recommending use of 91 AKI fuel only with an additional recommendation saying that 87 AKI may also be used but only with certain precautions.

http://www.nissan-techinfo.com/View.ash ... der2009-OM

Would this indicate that Nissan has had engine knock problems with the VQ40s from use of 87 AKI gasoline in some areas or that North American gasoline quality has degraded in some way. As a side note I`m starting to see more E-10 gasoline offered in this area.

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Re: 2009 fuel requirement change

Posted: Wed Oct 08, 2008 5:04 pm
by Npath
Greybrick wrote:In the 2005 - 2008 owners manuals Nissan recommended use of 87 AKI gasoline and 91 AKI only for 'improved vehicle performance' but looking through the 2009 PF owners manual, page 9-3 I see Nissan is now recommending use of 91 AKI fuel only with an additional recommendation saying that 87 AKI may also be used but only with certain precautions.

Would this indicate that Nissan has had engine knock problems with the VQ40s from use of 87 AKI gasoline in some areas or that North American gasoline quality has degraded in some way. As a side note I`m starting to see more E-10 gasoline offered in this area.
Hmm, I guess Nissan has changed the compression ratio slightly higher than 10:1. That would mean 09's would need premium fuel for the engine to run properly... or smoothly. 09 owners having a bottle of octane booster in the SUV would be a good idea. Oh well.

Re: 2009 fuel requirement change

Posted: Wed Oct 08, 2008 10:26 pm
by Gray
Npath wrote:Hmm, I guess Nissan has changed the compression ratio slightly higher than 10:1. That would mean 09's would need premium fuel for the engine to run properly... or smoothly. 09 owners having a bottle of octane booster in the SUV would be a good idea. Oh well.
I don`t think that the compression ratio has changed as the bore, stroke, displacement and horsepower is the same in the 2009 VQ40 as in previous years. I`m wondering if the 2009 premium fuel use requirement might be retroactive.

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Re: 2009 fuel requirement change

Posted: Wed Oct 08, 2008 11:10 pm
by 08Datsun
Greybrick wrote:
Npath wrote:Hmm, I guess Nissan has changed the compression ratio slightly higher than 10:1. That would mean 09's would need premium fuel for the engine to run properly... or smoothly. 09 owners having a bottle of octane booster in the SUV would be a good idea. Oh well.
I don`t think that the compression ratio has changed as the bore, stroke and horsepower is the same in the 2009 VQ40 as in years. I`m wondering if the 2009 premium fuel use requirement might be retroactive.

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You'd think they'd send us a message if it were. I doubt they will say anything so as to not get people all up in arms.

I couldn't find any info on the nissanusa site about the compression ratio, but the horsepower is the same. A marketing type site still listed the CR as 9.7, but I don't know if I'd trust that.

Just by odd coincidence, I just started putting in 91 as over the past weekend the PF was pinging here and there lugging six of us up a very steep and twisty mountain road. We'll see if I notice a difference.

Posted: Wed Oct 08, 2008 11:54 pm
by Gray
Thanks 08Datsun, this PF is run at elevations from about 2500` to about 5000` and usually at 30% or more relative humidity levels so even with about 1000 lb equipment loads I`ve never heard any pinging with 87 AKI gasoline. I stay away from stations offering `up to 10%` E10 gasohol blends, but that choice may become smaller in the future.

Interestingly the 2009 Frontier owners manual still recommends 87 AKI gasoline for the same VQ40 engine;

http://www.nissan-techinfo.com/View.ash ... ier2009-og

Here`s an excellent article on various ways to eleminate pinging in a Dodge engine other than resorting to premium fuel use;

http://dodgeram.org/tech/gas/Trouble/ping.htm

Maybe your knock sensor has failed.

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Posted: Thu Oct 09, 2008 5:08 am
by disallow
i agree with the fuel quality degradation. All regular and mid-grade gas in Manitoba is now potential 10% ethanol. What effect does that have to pinging? They tried to sell it by saying that ethanol is a natural anti-knock agent, but I have my doubts.

At first, while gas prices were below $1/liter, I switched to high octane just to avoid the ethanol. When the prices went up, the cheapness in me made me switch back to regular.

Posted: Thu Oct 09, 2008 6:43 am
by disallow
Just filled up from empty (10L still in the tank) with Esso 93 Octane.

Pinging is gone.

Is this a sign of a bad anti-knock sensor?

t

Posted: Thu Oct 09, 2008 7:43 am
by SHAWNATGERBROCK
I have ran 87 since new ( 92 only when towing over Mt Hood ) ( 76 Gas stations ) .... Never heard any signs of pinging ..... and has plenty of power !!

Posted: Thu Oct 09, 2008 4:12 pm
by Gray
Interestingly the Suzuki Equator with the VQ40 engine also asks for 87 AKI gasoline only. Have PF owners been overloading the truck and causing some issues with engine that has forced Nissan to ask for 91 AKI fuel in the 2009 PF?

http://east.suzukiequator.com/

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Re: 2009 fuel requirement change

Posted: Thu Oct 09, 2008 6:32 pm
by Gray
Npath wrote:Hmm, I guess Nissan has changed the compression ratio slightly higher than 10:1. That would mean 09's would need premium fuel for the engine to run properly... or smoothly. 09 owners having a bottle of octane booster in the SUV would be a good idea. Oh well.
From this NissanHelp spec sheet the 2009 VQ40 V6 PF is still listed as 9.7:1 compression ratio;

http://www.nissanhelp.com/Models/2009/p ... ations.htm

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Posted: Tue Mar 10, 2009 5:02 pm
by fat_frog
Bringing back a bit old thread, but my '09's fuel filler lid (or whatever it's officially called) says, something like premium unleaded fuel is recommended.

I also see the Owner's Manual (page 9-3...from Gray's post) says the same thing.

I only have less than 400 miles on odometer so far, and I have filled up the tank once....w/ regular unleaded, I am not hearing any pinging yet.

Posted: Sun Apr 12, 2009 5:25 pm
by Facevedo17
05 Pathy for me I try them all from 93 to 87 and 89 and actually find that when running 89 it last longer than running 93 ....I will observed this more closely when I fix my fuel sensor problem ...