Wow, why are you guys being suck d1c%s to this poster? He just didn't exactly understand what higher octane gas does. It doesn't increase horsepower, it increases the gas's resistance to detonation. And in cold weather (South Dakota right?) cars don't have to worry about detonation nearly as much. Without detonation, the car will get full timing and reach it's (or close to it) horsepower potential.

So when all of us in CA buy premium (and spend a few extra dollars per tank; who cares) we are just either following instructions, or trying to keep our cars from knocking and then making the computer retard the timing and loose some power.

 

Here's a little more info on why we are to use premium when it says too and not go cheap with lower octane.

This from TOM TORBJORNSEN on 'americas car show' radio show. Someone asked why they had to use high oct gas. (got this off AOL)

High octane is recommended because the engine is a high performance engine. High-octane fuel is more stable than low octane fuel in the volatile combustion chamber environment of the high output engine. Combustion chamber temps are higher in high output engines because of higher compression ratios. When you use low octane fuel, it has a tendency to pre-ignite or "knock" when it enters the combustion chamber. This causes an explosion in the upper regions of the combustion chamber. Continued use of low octane fuel in a high output engine will result in damage to the engine's cylinder heads and pistons.

 

That would make sense in a car or engine that REQUIRED premium. At least my 2004 AT sedan doesn't require it. And I don't push it THAT hard, the hardest I've pushed it recently was a 2500 mile road trip down I40 to/from vegas last month driving between 70 and 80mph. The 89 octane I used was fine (I didn't use the 85-86 octane gas I saw in some mountainous regions because it was below the required 87 octane in my owners manual).

No issues so far in 35K miles.

 

Unfortunately this guy loses credibility because he makes ZERO mention of the knock SENSOR that prevents damage by changing engine tuning IF knock is detected. Before I bought my G35, I ran my Acura TL on regualr for at least a year (after Katrina is when I started). It had plenty of acceleration, no stumbling or hesitation, and no pinging or knock that was ever noticed by me. That said, I *have* used premium in my brand new 06 G35. We'll see if I keep it up, but premium gave the TL no "boost" that I saw. This guy's argument is out of date with current technology to prevent engine damage.

 

Of course, the spark will retard (to a point) with lower octane gas. While that might keep it from pinging badly, it will also operate the car in a less efficient program than what the engine is capable of.
So even assuming there will be no damage, it will likely not be operating as efficiently. If you don't care, then run whatever you want.
Or follow the owner's manual recommendation knowing you will not have to assume anything as it will cover all possible conditions (temperature, climate, high speed, mountain roads, etc. etc.) you are likely to ever encounter driving it.
It makes the same sense in not running premium in a car with a regular fuel recommendation. I don't know why some people find that so difficult to understand.

 

you need to retest!

 

just curious.. what octane does the manuel recommend u to use for the TL?

 

Mine was a 2000 3.2TL, and 91 was recommended. It ran absolutely fine on 87.

 

first of all... a g-tech is a piece of sh**

second of all.. why would you even put 89 in your G?

thirdly... 91 is recommended for a reason. do some REAL research and then complain to nissan if it really bothers you that much.

 

the diffrence between 89 and 91 is minimal.. here in michigan we get 94 woot!

 

I have doubts if going over 91 makes a whole lot difference without a re-tune.
Off the showroom floor it should be a 50 state vehicle, meaning it is designed to run 91.
Get the ECU re-mapped for higher octane and that might be another animal.

 

Gtech is piece of ****??
You are just retarded....

Gtech is very very acurate,,,,i have used it for years,,, very usefull for telling if upgrades actualy make your car any faster...

 

Poor guy

 

Note for readers: the required octane for the early G35S is 87, but the manual says that "premium fuel is recommended for maximum performance."
So someone is not abusing their car or taking the cheapskate way out by running Regular in these cars.

If your driving style and requirements do not call for the maximum peformance that you would theoretically get from Premium fuel, then the beauty of the early cars is that they are flexible enough to accommodate.

I used several tanks of premium when I first bought my G35S new in May 02, then tried several tanks of regular. I really could not tell if there were any difference. I have since used Regular only.

 

i dont know if this matters but sometimes i do but low grade... maybe once in 1 month or 1 every two months when im running a little low on money....does it matter if different grades of gas mix??