Moderator: volvite
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.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.
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.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.
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.Greybrick wrote: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.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.
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From this NissanHelp spec sheet the 2009 VQ40 V6 PF is still listed as 9.7:1 compression ratio;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.