Have been running 93 octane as spec'd since buying by 2005 in January? With 93 running about $2.25 per gal., I wondering what is the down side to running 87 or mid-grade gas? anyone tried this?

 

Wish I could buy 93 octane gasoline to use with my TechnoSquare modded ECU. Out here in the west we are limited to 91 octane, and we're paying more than you are for 93. You can thank California for that.

To answer your question, yes you can use 89, or mid grade fuel, but why would you want to? The ECU will adapt itself to the lower grade gasoline at the expense of performance, and I believe you will feel the difference. BTW, all bets are off if you are talking about a 6MT, that car uses a recalibrated ECU, that needs premium, at least 91 octane.

Lou

 

I've been using 89 octane (currently $2.29/gallon) and have noticed no pinging or knocking. Since I could care less about beating the car next to me at the stop light in the quarter mile, I'm staying with the mid-grade and may even drop to the lower grade (87).

 

If you do that, you are going to screw up your engine and fuel system. The VQ in our G is designed to run premium fuel. Even if you are not driving hard, you will still hurt the engine since there are much residuals or some other stuff in the lower grade. So I hope you don't try it or your car will probably needs a trip to the shop sooner than you think.

 

Depends guys... The 03 an d 04 sedans I think had lower requirements.
The Coupe or any 05 you would be a complete fool to run less than 91.

As far as 'hearing' the pinging.... man by the time you hear it, it really bad, don't be thinking you will always hear it... and pinging is bad stuff !!! eats that engine alive.

 

Why would you scrimp on gas for a car like the G, buy a Honda Accord or something if you want to use regular, I don't get that.............
And no, the '04 still required Premium!

 

Again, 89 octane will work, but the ECU will compensate and back off the timing and reduce performance. The ECU is not designed to handle 87 octane, and I really don't know what will happen. I would imagine pre-ignition, but I really don't know. But, I wouldn't try it. If you do, let me know what happens.

However, I'm with ABQ_G35, why buy a G35, when a Honda Accord, Toyota Camry, or Nissan Altima would probably serve you well

Use the fuel recommended by the manufacturer. If you're modded, as I am, you really have no choice. Nor do I want one. Premium, if only 91 octane in the west, works fine for me.

Lou

 

if you drive about 12k miles per year you will use about 600 gallons of gas. is it worth having subpar performance to save 10cents a gallon or 60 bucks per year? NO WAY. not to mention that using a top tier gasoline like shell or chevron will keep your fuel system clean and avoid thos $500 injector cleanings.

i've used premium shell, amoco, or chevron in all my hi-po cars through the years and have never had to have the fuel systems cleaned even on cars with 150k miles.

so for my 2 cents....buy the premium, enjoy the performenace and save on future maintenance.

 

Don't buy a VQ35 Altima -- or any VQ35-equipped vehicle -- if you lean toward the cheap when filling your tank. Nissan recommends 91 octane for "best performance" in the Owner's Manual for every VQ35 engine but for the '05 6MT G35 sedan and coupe. In all likelihood it's the same deal for the '05 350Z 35th Anniversary Edition 6MT as well, which sports a VQ35 in essentially the same high state of tune. Nissan doesn't "recommend" 91 octane in these VQs; it requires it except under emergency circumstances.

Run standard-grade 87 octane in a VQ35 in a mild to moderate state of tune like the Maxima/Altima/'05 G35 5AT/'03-'04 G35 5AT & 6MT and you'll notice a little sluggishness and reduced horsepower. I know I did in my Altima 3.5. (I quickly went back to 93 octane.) The ECU, as mentioned, will retard ignition timing to combat pinging/predetonation. You'll probably never notice pinging at all, except possibly under heavy load coupled with high ambient temperatures. You'll just be driving a slow VQ35. And no, unless you abuse the heck out of the engine, you won't hurt a thing. It's a good bet that Nissan errs on the safe side in product liability when mentioning it's okay, but not optimal, to run standard 87 octane. The BS here about "residuals" (whatever they are) in the lower grades is totally untrue. The detergent package may be less in the lowest octane grade, but that's nothing to be concerned about. 87 octane is just as clean-burning and pure as 93 octane. Remember, Nissan is only concerned about predetonation with these engines, and hence is only concerned with octane rating.

Run the same fuel in highly tuned VQ35 like the '05 6MT G35/35th Anniversary Z at your own peril. The Owner's Manual is explicit on this.

Really, why drop $35K on a performance sedan/coupe if you're a cheap bastard? What's the point? If you can truly afford the car (and sadly in this day and age many driving around in them really can't), you can afford to feed it the proper fuel. Nissan's octane recommendations, just like its clearly defined break-in period and other maintenance outlines, are there so owners can enjoy their machines as they were designed.

While there will always be a few guys in the crowd espousing the merits of a little power steering fluid in the tank with each fill-up or other such nonsense, when you're paying this much for a car it makes zero sense IMHO to go against the manufacturer's guidelines. If $2.25-plus premium unleaded bothers you greatly, trade the G in on a Prius. (And that's not a slam, people. Priuses [Priii?] will run rings around a G35. Technically speaking. )

 

My last tank I paid $2.81/gallon - $45.50 for the tank! But really, 87 would have saved me what, ~$2.50? I'd rather pinch my pennies elsewhere. I like the car to go when I tell it to.

 

I have been putting in 89 for about a year now and haven't heard any pinging in the Wash DC area. Then again, I haven't been listening for it either. I also do not worry about beating the guy next to me. it doesn;t matter b/c the accord hybrid has just as many horses as i do now. how sad

 

Very well said That is exactly what I was thinking.

 

Take a look at this thread and specifically what Marty said. I thought this was very informative.

https://g35driver.com/forums/showthr...ight=additives

 

Good post, very interesting, thanks for the link marvinclt.

 

You've obviously got all the answers. And a place to put those that don't ascribe to your beliefs. Thanks for making this all so clear.