Let's start by saying that I am EXTREMELY picky about my Z and would never use anything less than 91 (and I would strongly advocate that others do the same).

I'm just curious as to whether the people on this forum who ask about gasoline grade have ever used 87 in their Zs and not had any engine knocking, breakdowns, engine explosions, etc.

 

my local dealer refuels their cars with 89 octane from the pumps on site...all the cars they sell are fueled as such that they test drive as well.

 

the dealer used 87 for the first 35 miles, after that I used 92. It hasnt knocked, but you can tell it was an 87 because of the exhaust sound. Id rev it at neutral a few times and you can definately hear the fuel burning inefficiently.

edit: ohh wait, couldve been an 89.

 

When I got mine it came with a free tank of 87. I didn't take it over 4500 rpm and never past 2/3 throttle. I also put an octane booster in after about 50 miles.

 

I was thinking of adding additives to the gas tank. I just dont know exactly when to start doing it.... any pointers?

 

Using a lower octane on a modern car with a knock sensor and dynamic closed loop timing control will not damage the engine. The ECU will simply retard timing, and possibly increase the A/F to accomodate it.

But it will definitely result in loss of performance.

bill

 

The mods should consider making the sticky thread an open discussion instead of a one post closure. I understand, it should be a one post, "it's as simple as this", "there is nothing to talk about", "end of story", but as it is, these threads are going to keep popping up. Might as well keep it all in one thread??

 

I reccomend what the owners manual says......

 

I just picked one up at the auto store and since the tank was almost full I just put it in the top. Ideally, you'd probably want to put the additive in and then fill up, but if given that choice, just put 93 in since 87 + additive costs more than 93 (or 91 depending on where you live).

 

Some will argue that it has to sense knock to retard and by sensing knock that means it did knock and hence damage to the engine. I think that's an over-generalization and tend to think your statement is right, that the car will adjust and no damage will occur.

 

Owner's manual says something like if you are forced to put lesser gas in, only put in the minimum you have to (say you know you need to go 50 miles, then only put 3 gallons in), and then at the next filling fill up with the proper unleaded gas.

 

when i got my 383 in my camaro anything under 91 would make the car sputter and hesitate really bad!

 

A motor build with high octane fuel in mind can only retard the timing so far before it just knocks anyway (like a diesel). On other Nissan VQ products they "Recommend High Octane for best performance" but you can run them on lower grade flue, on the Z they require it. Sure maybe if you are driving in Kansas on a cool fall day, you can get away with it on the other hand, on a hot day, under load, it's a bad idea.

Also, adding octane booster to 87 wont even get you 89.

Chris

 

The dealership put regular in mine when I first bought it and it never knocked. It just runs less aggressive maps to adjust and keep from knocking. Not good for performance but it will run on 87. I don't put anything but premium in though because I want to take care of my baby, .

 

But when (at what mileage) should I put additives to the gasoline.

 

A modern knock response system will sense potential knock, and take corrective action, long before it can cause any damage.

These systems are actually designed to keep the ignition curve near the knock limit, as this is where the engine can safey make max power, and operate at max efficiency.

bill

 

https://my350z.com/forum/showthread.php?t=188064

doesnt hurt to search

 

Putting 87 in might not be what the manual says to do, but your engine isn't going to explode....that doesn't even make sense. I cheaped out on a couple tanks when I first bought the car, but I decided that I was just being stupid by not wanting to pay an extra $3 for a car I just paid thousands of dollars for (or signed a piece of paper to that effect rather). The only difference is that 93 feels a lot more powerful than 87. I'm sure over a long period of time using 87 is not a good idea, but why cheap out a couple dollars?

 

ECU will pull timing and everything will be fine.

Your performance will suck.

you will need to reset your ECU once you put in some 91+ again

NOT recommended for turbo guys (if you're F/I and reading this and didn't know this then )

 

LOL