pimpin-tl

No, when a car is tuned for premium fuel, it will not GAIN for higher octane over 93 octane which it was designed for. It will however lose a lot of power if you go down in octane. Maybe cause I race, I see the difference of octane more noticeably in my cars.

fast-tl

Undoubtedly, .

iTimmy

Consider yourself lucky. I have no clue where the 30HP thing came from, but I wouldn't stand behind that either.

Race fuel will damage a modern car that is not designed to run really high octane, it typically burns the Cat's, damages O2 sensor's... etc.

CLpower

I've got a Murano rental, and i f'ing LOVE this car




but i put in 89

cusdaddy

I know that one of the Sport Performance mags (can't remember which one) did a test with the 350Z when it came out comparing dyno runs on the same car for 93 Octane versus 91 Octane which is the available in CA. They experienced from what I remember about a 3-4whp reduction in power.

I'm not sure of a 30whp reduction, but it will definitely reduce power significantly between 93 and 87 Octane with the VQ as timing is pulled (especially the high output versions of the VQ)

F23A4

.....and I love being a Murano owner!! (Sidenote: I thought about this thread as I was filling up my Murano with V-Power last night. )

Scrib

CLpower

hey, it's a rental, I should be putting in 87

RandyMax

^^^ Agreed.

My Murano actually pings under load with anything other than 91. So did my Maxima.

RandyMax

Whoa Scrib is an Admin now? Congrats!

fsttyms1

I remember reading a few years back that a magazine did the test on a Honda Odyssey and it lost somewhere in the relm of 26hp and close to a second and a half in the 1/4. Most people cant tell the difference in hp. Butt dynos are not very accurate, and variances in weather and stuff from a day to day basis make it harder, best would be to have to identical cars and run them together. And no the same isnt so for using race fuel. One needs to understand the way fuel works before making statements like that. Also alot of pinging is done on a level that you cant hear. and thats the dangerous stuff

fast-tl

I would agree that butt dynos aren't accurate, but I would argue that if my 225 hp TL was down to 200 or less due to using 87 octane, I believe that would be noticeable. Maybe 5 to maybe 10 hp might be hard to recognize as a gain or loss, but 30hp, I don't know. Lots of aftermarket folks would be out of business if people didn't notice a 30 hp loss or gain.

F23A4

Then again, those who partake in the purchase of aftermarket performance parts (like many on this board) are likely to see these gains (or losses) on time slips and dyno charts and not be too concerned about an unquantifiable butt dyno. (Incidentally, some of those performance aftermarket companies need to be out of business if their parts do not show gains on a dyno.)

While I do believe Premium vs Regular will yield a difference in horsepower on the VQ35DE/HR, I would be amazed if the difference was as much as 30hp. (That difference seems more credible if it were a 4G63 or EJ257, where FI is at play.)

I did come across this 'read' in Nissan Performance magazine though:

I have been doing some research and was wondering: I have a Murano (VQ35DE engine, 10.3:1 CR). Can I change my plugs one step colder, and run 89 instead of 91 octane gas? I want nothing to do with detonation (and timing retard), and if I'm sacrificing a significant portion of the plug life by doing this, I won't. I ALWAYS drive long enough for my engine to reach operating temperature. The reason for this question is performance, not cost. - Tyler

The Murano can run cheaper low octane gas, but you will lose about 10-15 horsepower as the ECU controls the negligible pinging. Since it's performance, not money, you are interested in, stick to 91 octane. Octane ratings determine the ignition point of the gasoline. A higher octane raises the ignition point to eliminate early burning. If the ignition point (octane) is too low, the fuel can burn too early in the cylinders and cause pinging. Spark plug heat ranges determine how efficient the plug is at removing heat from the combustion chamber and dissipating it into the cooling system. The length of the insulator nose, or part from the firing tip to the shell, decides the heat range. Spark plugs must maintain an operating temperature between 500 and 850 degrees Celsius (about 950-1550 degrees Farenheit). Different heat ranges are selected for engines based upon these needs. Too low a temp and the electrode won’t be hot enough to burn off carbon and combustion chamber deposits. The plug could foul or cause misfire. Too high a temp and the electrode may melt causing pre-ignition (fuel explodes too early and reaches peak pressure before the piston is at TDC) or detonation (occurs between ignition and TDC when the gases explode before the spark plug flame reaches them). A “hot” spark plug has a longer insulator nose and the firing end heats up more quickly, but dissipates heat more slowly. A “cold” spark plug has a shorter insulator nose. Since the heat has less distance to travel, the plug can transfer the heat more quickly. Colder plugs are necessary on highly modified cars, cars under load, or cars run at high rpm for long periods of time or long distance high speed driving. Hotter plugs are good for stop and go cars as they will burn off the oil and carbon deposits easier. You can go with a heat range cooler if you’re doing a lot of highway driving, but keep filling up with 91 octane if you want the most power from your VQ35DE.

LINK

keg1997

Pinging...what is that

Let's be honest folks....this board is full of folks who care deeply about their vehicles and in some cases want/need to extract every iota of "performance" from their vehicles. We are a different bunch and not like 80-90% (my estimate) of the car owners in the country. Let's face it, when I tell people that I mail order my car polish, they look at me like I have 5 ears b/c they prefer the "wax" that they get from the gas station drive thru car wash.

Having said that....do you really think that running regular when a manual "recommends" premium is truly the end of the world? Would we not be hearing Consumer Reports, Motor Trend/C&D/Autoweek, etc running a story about these multitude of engine failures due to ignorant owners not putting the proper fuel type in their vehicles? Perhaps, I've missed those articles, but I have yet to see them...

In fact, I recall C&D doing a comparison on several vehicles with different fuel grades in them, and while I can't quote the results, it did not change my fuel-buying behavior. Somebody here probably can remember better than I, but I remember a negible difference in many of the engines with regular or premium fuel in them.

Point of this....if you really want to put premium in your vehicle....have at it But you don't HAVE to....

iTimmy

A lot of people talk out of their asses, in particular on forums

zamo

2 Nissan mechanics told me that pinging does not harm the engine. Where can I get info about this?

pimpin-tl

OMG those mechanics are idiots. It damages the engine if it pings. Why you think there are sensors to prevent it?!

zamo

They told me that knocking harms the engine, not pinging. I am not sure what is the difference between them.

cusdaddy

Knocking and pinging are the exact same thing. Just 2 different terms people use.

Here is more info on it for your reference:

http://en.wikipedia.org/wiki/Engine_knocking

zamo

^^ Thanks. I wonder why Nissan suggests 87 for my Altima, and it pings eventually.

F23A4

Refer to post# 16 in this thread. LINK