Regular Gas?
 

I think the dealer may have filled up (topped off) the tank with regular gas. Do any of you know first hand how the engine reacts when this is done.

I know what the manual says about regular gas.

What I am trying to figure out is, what the symptoms are to see if they match what I am seeing.

welllll what are your symptoms!??

I don't think one fill-up will hurt you at all. Nissan also requires premium fuel for the Maxima and the 3.5 Altima. Those cars are popular for rental companies. How many people do you know that fill up rental cars with premium?

My 350z takes premium also. I have been putting regular in my car every other fill up for a few years, I don't notice any type of issues.

just keep adding premium into the tank every chance you can get. Im sure if you wanted to you could syphon alot out but idunno doesnt seeem like fun.

on after thought it might actualy be 91 octane but from the cheapest crappyes gas station they could find a discount at.

I had no idea what the dealer put into mine but i can only assume it was crap so i kept putting chevron in it every day hoping to mix the good stuff with what ever they put in.

dont worry about it.

when your car is new, you cant (shouldn't, unless you believe in breaking it in by the dyno) rev it above 4kRPM's or so.

the lower octane gas will not do anything to your motor, as a mater of fact, if you plan on keeping the engine below 4krpm for 500+ miles (break in period?), then you might as well use regular gas for the 500+ miles. (although I wouldn't, the price difference isn't much of anything)

the reason premium is required is because the 370z's engine has high compression which will make low octane gasoline detonate BEFORE it reaches the combustion stroke.
there is an exception to that - which is if the engine is not under stress to put out the power, then the gas will not misfire, thus making 87 octane perfectly fine to use. You just have to remember not to floor it.

on top of that, many new cars have smarter ECU's that will regulate the misfiring to prevent damage. (although not all cars have it, and not always successful)

Probably just my imagination, but it "feels" like it misses in a VERY minor way every once in a while. It is not an obvious miss.

If you look in your manual, because I do recall reading it, it says that if it's an "emergency," you can put 87 octane in. However, don't drive hard i.e. don't get on it.

When I had a CRX with a b16a (modded w/ JDM CTR cams, DC headers, high flow cats and Greddy exhaust), I always put in 89 and it didn't hurt it. My motor had over 100K on it and it still felt like the compression was strong....Hate to say this, but when I first dropped that motor in my CRX HF, I'm confident that it could beat a stock 370Z by a hair to say the least in the 1/4.

104
 

Damn I miss that 104 I used to get in Japan. Those were the good ole days.:shakes head:

When i picked up my 370z at the dealership, they've also filled my Z's tank with 89

octane gas, eventhough the minimum recommendation for octane usage is 91. :mad:

However, i don't think it damaged my engine at all, but i can ensure you that when you

fill your Z's tank with 91 octane, you can feel minor improvement compare to 89.(only if

you are extreamly sensitive person.)Personally, i put premium gas(94octane) everytime i

fill my Z's tank, and i can feel way better power than 89 octane. Occasionally, i put

Lucas octane booster with premium gas(94), which it might be raise the octane number

up to 98(approxi), and it makes me think that i've moded my Z

eventhough it's 100% stock. Just opinion :p

some of you guys are funny.....higher octane does not = higher HP output

The car is built for 91 octane, lower octane will produce knock which will cause the ECU to retard the timing and reduce power. Normally increasing octane does not increase power output as the ECU does not advance timing beyond it's preset.

However in this car it actually might. The engine computer reportedly continues to advance the timing until it detects knock. There's been reports of high octane race gas producing a measurable power boost on the dyno. How true this is I don't know, haven't been able to measure this first hand.

That said I use 93 because they don't have 91 locally.

I know for a fact that the 06 Accord V6 I had recommended regular gas but would advance the timing as much as it could. A Honda Engineer actually stated in an interview that you would gain about 10hp by using premium.

I see no reason why the 370Z can't be doing the same. But thanks for coming in Mr. 14Posts and trying to talk down to everyone.

:iagree: Exactly..

My Corvette had 2 distinct timing maps. When knock was detected it would default to the Low octane Map. It's amazing how many cheapskate Vette owners run regular! Most Import ECU systems are a little more sophisticated and alter timing dynamically, always seeking the most advance possible up to the knock threshold.

BUT more timing does..