attn 90-95 WD21 users: what kind of gas do you use?

[ajspath]

i've been using premium for at least a year but lately gas prices have been killing me. i don't have the manual; what does it say about the kind of gasoline we should use? is it okay to use the low-graded gasoline?

 

edit: is there really no poll option on these forums?

Edited August 26, 2009 by ajspath

[MY1PATH]

87 octane is fine for these ol rigs. Premium yeilds no beniftit to these engines as they are not optimized for it.

[MikeV]

trucks are happy with 87, I just add sea-foam a couple times a year to keep her clean.

[Precise1]

X3

 

The cheapest Arco 87 octane I can find with an occasional dose of Lucas injector cleaner (usually when I see it on sale for $5). No problems, no worries...

 

B

[Precise1]

edit: is there really no poll option on these forums?

Sue there is!! Right above the menus and below the header with the name of the thread.

 

"Poll Options Click here to manage this topic's poll "

 

Don't worry, we'll catch you when you fall...

 

B

[OldSlowReliable]

whatever 'unleaded' is.... its what I was raised putting into anything (cept for diesel of course) and I have never used foam or injector cleaners or anything......but whatevs, im on a very fixed income, so its all I can do to keep filling up my 20mpg city CAR, usually I just throw a few bucks into the pathy when I feel like driving it....

[KovemaN]

87 octane is fine for these ol rigs. Premium yeilds no beniftit to these engines as they are not optimized for it.

 

The Nissans with knock sensors actually have multiple timing maps. When I use 91 on a regular basis I get better gas mileage from my trucks. In my D21 I get at least 10% better fuel economy from premium. The ECU will try to use the high octane map, but if it detects knock it will revert to the regular map. If no knock is detected the ECU will automatically advance the timing. That is the whole point of the knock sensor.

[GrimGreg]

87, the engine was made to run on it.

[blackspawn]

87 yep...

[Indigent]

I feel the need to chime in on this. There is absolutely NO high octane fuel map in the Pathfinder ECU. I have the bin files if you would like to look at them sometime (from 1987,1990,1991,1995.)

There is a knock fuel map and a normal fuel map. Some Nissan ECUs (300ZX for example) have the high octane, regular octane, and knock, but not the Pathy. Additionally, the knock fuel map only reduces injector pulsewidth in the 2000-3500 RPM range.

These ECUs timing maps are tuned for 87 octane. There is only one timing map, and the knock sensor is only monitoring the area of the last 3 columns and upper 9 rows of that map. The area outlined in red in the picture.

The knock sensor in the Pathfinder is suprisingly not very effectively utilized. Compared to the 300zx that has a whole seperate knock timing map.

To boil that down, the Pathfinder ECU is not listening for knock except at the very highest engine loads (MAF reading) and only up to about 4400 RPM.

 

For some reason the picture doesn't show, but if you click on it it works.

Edited August 28, 2009 by Indigent

[KovemaN]

My mistake then. I thought all of the VG30E ECUs had the high octane map.

[unccpathfinder]

87....

[Tungsten]

I use 89...just seems better. Since gas goes bad, I think 87 is really like a little lower. If you let 89 spoil, its perfect! lol

Also, I get smoother performance on 89 than on 87 but if I put in 87 it works fine. I guess it depends on the gas station too.

I tried using higher octanes like 93 and 95, the engine just revs higher to accelerate. FYI, I got 20 mpgs on all octanes.

Edited September 6, 2009 by Tungsten

[GoPathyGo]

I wouldn't worry about gas going bad unless you're filling at a station with very light traffic that has had the stuff sitting around forever. If it has, chances are it's going out of business pretty soon.

 

Older engines do fine on 87. Considering the $0.30 spread to 93 octane and a 16-20 average mpg, you could save $200-$300/year on a truck driven 15,000 miles/year. That oughta buy at least 1 bottle of fuel injector cleaner a month.

Edited September 7, 2009 by GoPathyGo

[DavefromOZ]

Mine drinks diesel.

[5523Pathfinder]

I use 87. Average 19-20mpg. Im on the freeway alot.

 

I have put 89 octane in and my mileage dropped.

[Tungsten]

I would say using premium did clean the engine up a bit so consider premium as an alternate to the cleaner bottle. lol

 

Using higher grades did not do anything to my gas mileage on the highway, the engine does waste more gas however because it has to rev more to get speed.

 

I love the VG30E

[magregor]

89 octane with 10% ethanol

[nismothunder]

Hum...I've been running 114 leaded in mine...and to think I could of gotten away with just 87...

Summer I use 87 and winter I use 89(theres less then a 2 cent diffrence at the one gas station so I get the "better" stuff.

[FrostTheOne]

Here in Edmonton, Husky started selling 91 as their regular and 94 as their premium. So 91 for same price as 87 everywhere else. But when I was using the 91 my engine was running real hot, like top 3/4 of temp gauge (almost topped out on hot days.) Was getting about another 90-100km to a tank. But switched back to Shell 87 and have maintained the milage.

 

Cleaned out the engine residue maybe? Well whatever it runs cool again and I kept the milage, so YEAH ME!

[TerranoNZ]

98oct, My lot seems to run better

[Drunkencat]

I use 92 octane in all of my vehicles. The rig seems to run better and what is an extra $2 a tank.

Edited September 11, 2009 by Drunkencat

[adamzan]

I don't know about you guys but around here it's not an octane rating on the pump but an "anti-knock index"

 

I just use 89

[nunya]

87 does just fine for me

[Alkorahil]

My truck hates 87 and lets me know it when I put it in. I ususaly put 89 in it..... and now she has gotten spoiled.

Edited September 12, 2009 by Alkorahil