I am taking back my opinion that 87 octaine was no different

M4ck · Sep 23, 2004

Well I had said that I didn't notice a difference when I switched from 91 to 87 octaine. Well I decided to try a tank of 91 because it was a good price. I have been running on it 2 days now. I am not 100% sure that its not where I bought it as opposed to the octaine level. I got this 91 at a different station than I usually go to. Well for that last 2 days my truck has been driving smoother and also feels more peppy. Not anything outrageous just enough to tell a difference. Maybe I'm crazy or maybe its just a better gas quality at this station, but I believe I will start using 91 for a while. What do you guys think about this finding.
M4ck

JetTech · Sep 23, 2004

I think it's very a real observation. I have yet to do any octane testing with my OBD2 cable and laptop but can tell you that by using a slower burning higher octance fuel comes less emissions. I'll try to do some testing soon and see if a higher octance fuel increases timing any. Stay tuned!!

ttammunek04 · Sep 23, 2004

Re: I am taking back my opinion that 87 octaine was no diffe

m4ck said:
Well I had said that I didn't notice a difference when I switched from 91 to 87 octaine. Well I decided to try a tank of 91 because it was a good price. I have been running on it 2 days now. I am not 100% sure that its not where I bought it as opposed to the octaine level. I got this 91 at a different station than I usually go to. Well for that last 2 days my truck has been driving smoother and also feels more peppy. Not anything outrageous just enough to tell a difference. Maybe I'm crazy or maybe its just a better gas quality at this station, but I believe I will start using 91 for a while. What do you guys think about this finding.
M4ck

Yeah I thought that you would reconsider my poll after trying a different gas. Just kidding, It does seem to make a slight difference though.

Sr2 · Sep 24, 2004

Gentleman,
My bet is that octane has little to do with the overall performance of the gasoline. Afterall all octane measures is the ability of a gasoline to resist pre-ignition. Octane has no bearing on the "energy" available from a gasoline. My guess is that buying gasoline from a reputable refinery will yield better performance in most all applications. Hop onto VP/Sunoco et al websites and I'm sure you'll find gasolines of similar octanes (research or motor octanes) that will far out perform pump gas in any application. The question is are we willing to pay for it, let alone find a place that sells those gasolines?? Living in Denver I can tell you that having oxy gasoline (ethanol) sucks. These types of fuels lower mileage for the sake of lowered CO emissions. I routinely get the mileage that the sticker says I should get. However living at an elevation of 5500' MSL one would think that my truck would get better mileage here at altitude. If for no other reason than the engine ought to be mixing less fuel with the available atmosphere here. Just my two cents...bye the way does anyone know of a manufacturer that might build a turbocharger for this engine? That would make our trucks all that and a box of chocolates.
Regards,
Sam

BiXLL · Sep 24, 2004

What do you guys think about this finding.

I think you found some good drugs! It has all been said before, but go ahead and spend the extra money if it makes you feel better!

M4ck · Sep 24, 2004

Spending extra money doesn't make me feel better but I swear that I can see a difference I'm wondering more if its the difference in brand because this was from 2 different gas stations.
M4ck

Matt007az · Oct 19, 2006

yeah 91 is good for the titan .. so what if it costs a few dollars more to fill up

ChicksDigEmToo · Oct 19, 2006

I did the opposite a few months back...went from 91 to 87 octane. I also switched stations. My truck gets better mpg and runs smoother on the lower octane. But my guess is that it runs smoother with the better gas source. Went to BP gas. Tried Texaco and Valero in the past few weeks and my mpg and performance suffered. So all in all...I think that what you are seeing in the higher octane is actually just a better quality gas from a better station. Try the lower octane at that station and see what happens.

Just realized this was an OLD thread....

dang it! sorry!

Fordman07 · Oct 19, 2006

The truck is designed to burn 87. You will generally get ur best results using 87 unless someone comes out with a Tuner. Then 91+ would be better.

OOOOOps way old thread my bad.

Toomnymods · Oct 19, 2006

i have to run 93 octane in my rig since i have a nitrous setup now..

SPEEDDEMON · Oct 19, 2006

I have tried this with 89 and 87 octane from the same station and all I can say is that this truck likes the lower octane not only did my mpg increase I found it ran a lot smoother. The question really is how high a quality is the gas, some 87's might be a better quality than some 89's or 93's. Another question is how long is the 91 or 93 sitting in the tank before it is sold, most people use regular so I think it comes down to buying quality gas whatever you use !!

Kolia · Oct 19, 2006

Just make sure your gas station is one that sees a lot of traffic. This will lower the chance of getting some "bad" gas.

Higher octane fuel will have different additives that will help the engine run cleaner and smoother. It's not just knock resistance that's different.

I run premium V-Power only in my Titan. I'd do it even if it was more expensive. It just turn's out the improved mileage from the premium out weight the price difference. I hit reserve at 320-340 miles with regular and at 360-370 miles with premium. Driving habits will affect that a lot. I do 60 miles a day, mostly highway, cruising at 70 mph.

Yes, the topic has been beaten to death. Most people that say fuel grade doesn't make a difference have no idea how an IC engine works... Just get a good engine tunning book, skip to the ignition timing section.

TOWS2Zs · Oct 19, 2006

Fordman07 said:
The truck is designed to burn 87. You will generally get ur best results using 87 unless someone comes out with a Tuner. Then 91+ would be better.

The same engine in the QX56 recommends 91...

Fordman07 · Oct 20, 2006

The same engine in the QX56 recommends 91...

im sure their are suttle diferences that account for that.

Toomnymods · Oct 20, 2006

the engine i the same but it has advanced timing to account for the increased hp

M4ck · Oct 20, 2006

wow these old posts are getting drug up the last few days.
I will be switching to 93 as well as soon as I get the opportunity to install my nitrous kit. Its sad its just sitting in my garage collecting dust for the last few weeks.
M4ck

Toomnymods · Oct 20, 2006

no performance shops around you to install it?? they will prob charge you 400-800 to install the kit..
did you also end up getting the msd window switch with the fuel rail adapter and plugs?

M4ck · Oct 20, 2006

Still need the switch and adapter.

TOWS2Zs · Oct 20, 2006

Toomnymods said:
the engine i the same but it has advanced timing to account for the increased hp

Hmm, AFAIK all Nissan and Infiniti engines are set at 15^ BTDC...

Toomnymods · Oct 20, 2006

nope not the armada and the qx56.. they have advanced timing to account for thier increased hp.. that's why THEY HAVE TO RUN SUPREME UNLEADED

I am taking back my opinion that 87 octaine was no different

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