Thats not true. You can run off 87 just fine. Plenty of people have done it. You'll lose performance and can be susceptible to knocking if you try to run it crazy. I've run that before with no problems at all.

 

Update: I took my car to the dealer today and had them check over it. They looked at the timing chain and tensioner, said both were fine. They adjusted the timing between 1/2 and 1 degree (the service manager wasn't clear on exactly how much or even which direction - though I assume it must have been retarded). It pinged a few times on the way home, as the ECU adjusted after having been reset. After a few WOT acceleration runs, the pinging went away. I'll keep you guys updated if it comes back.

Side note: the whine that I posted on the previous page is still there, though quieter now.

 

You're right,you can run 87 octane. But unless you drive a sedan why would you want to? It baffles me that people would spend $$$ on a sports car and not put the proper fuel in it.

From pg. 9-3 of the owner's manual;

Coupe models-"Use unleaded premium gasoline with an octane rating of at least 91AKI(anti-knock index)number(Research octane number 96). If premium gasoline is not available,unleaded regular gasoline with an octane rating of 87 AKI number(Research octane number 91)may be temporarily used,but only under the following precautions:
*Have the fuel tank filled only partially with regular unleaded gasoline,and fill up with premium unleaded gasoline as soon as possible.
*Avoid full throttle driving and abrupt acceleration."

 

Hmmm...I read a bit more and came across this on pg. 9-4;

"However,now and then you may notice light spark knock for a short time while accelerating or driving up hills. This is no cause for concern,because you get the greatest fuel benefit when there is light spark knock for a short time under heavy engine load."

Methinks possibly nothing was wrong with your car. The dealer probably retarded the timing which doesn't surprise me,from what you've posted about them they sound like retards.

 

It is the one I had to drive about 40-50 miles for. At first I thought it was the timing chain tensioner so I figured the 30-45 minute drive was nothing to save me over $1000. Turned out that all they did was adjust it (though I still think there's an underlying problem), but whatever. I'm not going to complain about driving the G .

As far as the dealer goes, I'm hoping the tech knew what he did, haha. The service manager just wasn't clear when he told me. He simply said "They adjusted your timing by about 1/2 to 1 degree." I assume they must have retarded it.

I see that too now, very interesting. The knocking I heard before I would call excessive though. Now I hear very light knock, every once in a while, and it doesn't last as long.

I still hear that whining though. I'm actually going to Sacramento for the week so I'm going to have it looked at by another Infiniti dealership there and see what they say. Again, I'll keep you guys updated.

 

my car runs very flat, runs the same with 89 octane mid grade or 93 octane high test...I am guessing that the previous owner had timing reduced to get better has mileage with mid grade. the car does not ping on any gas. I have accurately checked gas mileage and on trips measuring actual gas used with accurate mileage driven the car gets 27.2, not bad at all. How to check spark timing? I see that the underhood sticker says 15 degrees. How can I check to see what I have and advance it if I am right that it has been set back...thanx

 

Still have pinging, I still don't think it's the gas. I'm changing out the plugs soon for one step colder plugs and I'll be double checking all of my gaps and coil packs. I'll let you know what I find.

 

Let us know about stepping down on the plug heat range.

 

Have you bottom out your car lately? I had the same issues and it cost me $$$ changing fluids and other stuff, just to find out it was a loose bracket that connects the exhaust pipe to the tranny case. Everytime there is a change in speed, the bracket would hit each other and it sounds like pinging. Cost me $20 to have it welded.

 

Definitely not bottoming out as it was directly related to throttle/engine load and not location, speed or road conditions.

As an update, I ordered my spark plugs yesterday from Kragen (only place that could get them to me the next morning). I went with the one step colder PLFR6A-11 from NGK. Expect to pay around $12 a plug for these, even from online vendors.

I spent this afternoon changing the spark plugs and going for a few test drives. First of all, for those who haven't changed the spark plugs in this car, prepare to be very frustrated with the wiring harness going over the ignition coils. It was completely in the way of getting the bad plugs out, even after unbolting the brackets and trying to move it. With that said, the actual spark plug install is very simple, took me no more than 2 hours (working fairly casually and trying to get that wiring harness out of the way - most of the time was spend manipulating my hands to be able to grab the coils).

First thing I did was check the old plugs. As expected, they were NGK PLFR5A plugs. Next I checked the gaps on all of the plugs. Save maybe one plug, they were all pretty much exactly gapped at .044", so that was taken care of. I double and triple checked the gaps on the new plugs and installed them, torqued down to 16ft/lb with anti-seize on the threads. I also took this opportunity to check for any oil pooling in the coils, and there was none.

Anyway, after taking the G for a drive I could not get it to ping like before. I could count the number of individual pings on both hands, after driving approximately 20 miles and being hard on it. I would consider this light spark knock, since before I couldn't count the number of pings on both hands and both feet after 5 miles of driving hard. I tried everything from short, low-RPM pulls to high RPM runs and all the way through the band at 100% throttle. The only pinging I could hear was when I was at VERY low RPM (maybe 1000) in 2nd gear - which I think is expected since that puts a lot of load on the engine.

So, bottom line is: if anyone is having pinging issues with their engine, try changing the plugs before you spend ridiculous amounts of money on other things. I spent $80 for all six plugs and spent 2 hours changing it. Definitely more worth it than even a single hour of dealership labor. For anyone curious as to the part number: NGK PLFR6A-11. They are OEM specified spark plugs and are one step colder than the stock plugs. They helped in my situation!

 

My motor and plugs have approx 10k miles on it and is pinging as well as having less power than the original motor. I need to figure out how to adjust the timing myself so I can play with it.

 

timing is controlled electronically through the ECU