Premium Gas ...

[C-Kwik]

Actually, if you want, you can make better use of premium fuel without any more than the additional cost of the fuel itself. The main reason to use a higher octane fuel is because of it's higher point of detonation. The primary causes of detonation is heat and/or pressure. Someone already mentioned higher compression. Boost is of course another way you can increase heat and pressure. So is leaning out the fuel curve and advancing the timing. You can advance the timing for free and use premium fuel to get a little more power and better gas mileage. You will get a higher peak cylinder pressure by doing this and if you increase cylinder pressure, you can use the energy from the gas more effectively. It actually puts more of the energy into pushing the piston down then into the cooling system. And as long as you are not detonating, that is healthier for the motor.

[C-Kwik]

Well, like everything else, results may vary. But it is a proven way of making power. But it's usually only a minor increase. Even a reprogrammed ECU will generally run a more advanced timing curve and a leaner mixture and will only make a peak gain of about 8 HP if your lucky. The difference is more noticable in turbo motors...

[klorocks]

all in all , spending the extra cash on premium is a fn rip, i think mid or low grade is fine.

Actuallity, mid and high grade is just another plot for the man to steal more pennies out of your pocket!!!!!! Damnit, there shouldent be a choice, just my 2 cents, driven by about 13 new castles

[klorocks]

hahahahahahaha, abnother war won by the man

[SlowFiveOh]

yes in the new z it is very possible to gain 9 horsepower by running higher octane fuel because it will allow the computer to advance the timing to a more optimal range. if you run 87 in it the knock sensor will back the timing off when it senses detonation since it will be more prown to detonation thus reducing power output to some extent.

[240SXer]

I just put midgrade in this tank, let's see how it does. I've been putting premium in so far, my gas mileage is HORRIBLE, I race around like most of the time, but come on, it's like 14mpg. That's uncalled for. I raced an SI up to 120mph, and I seriously lost like 1/8 of a tank doing it. It dropped noticeably. I haven't noticed a lack of performance with midgrade yet.

[Tino]

yea gas sucks hog

[fenrisx]

Ok, I didn't read all the posts, and I don't know if anyone has mentioned this yet, but 240sx's are supposed to use premium gas. It's in the owners manual(atleast for the '92 model). Sorry if someone already mentioned this, I did see where someone said they 'thought' it is supposed to use premium. :thinker

[Tino]

it don't matter, unless your racing. Even if your not unless there money on the line

[Mayhem_J30]

manufacturer is right.cars are designed for a certain octane level, rather it's 92+/-.if you're car is designed for premium and you're using below 92 the timing is retarded to prevent knocking. when this is done your car is not running at optimum therefore getting less gas mileage. It's most likely cheaper to go ahead and purchase the premium as required. The case is true on the opposite. If "Regular" is required you're throwing money away on higher octane fuel or octane fuel additives. This is unless of course as someone mentioned earlier, timing changes are done and the ECU is happy with it.Do a search in the Infiniti section for fuel and octane and there's been many discussions regarding this.

Tino, your responses are interesting as I have not yet ever heard of that. Are you talking about FI's getting clogged? Try running FI cleaner on regular intervals aprox 3000 miles or every oil change. Rail flush once a year. Switch to Chevron w/Techron to help prevent build up while you're at it. That build up is probably from the fuel the rest of the country uses like Exxon.

[Mayhem_J30]

some good links to threads:http://www.nissaninfiniticlub....ctanehttp://www.nissaninfiniticlub....ctanehttp://www.nissaninfiniticlub....ctane

[SpeeDDrifT]

thank you mayhem for the first useful bit of information i've read in this post (with explanation):rolleyes

[Mayhem_J30]

thank you mayhem for the first useful bit of information i've read in this post (with explanation):rolleyes

your welcome...i think..you had the :rolleyes in effect and internet attitude is hard to judge through an emotionless medium like text. but all the thanks should go to the participators in those conversations, like Q45Tech and Palmerwmd.

[SpeeDDrifT]

:rolleyes meant 3 pages of no hard facts on this thread..

[Tino]

I'm just saying higher octanes have some sort of detergents that leave a residual biuld up.

[PalmerWMD]

I'm just saying higher octanes have some sort of detergents that leave a residual biuld up.

Tino:

a lot of formulations actually have more detergents in theor premium gas.

Fred...

[Tino]

yea... like i said

[PalmerWMD]

some good links to threads:http://www.nissaninfiniticlub....ctanehttp://www.nissaninfiniticlub....ctanehttp://www.nissaninfiniticlub....ctane

Great links Chris!

Fred....

[PalmerWMD]

yea... like i said

LOl a misunderstanding either on my part or yours.

detergents dont leave residues, they clean them up.

Fred...

[silviamirage]

s13 drifter -the fuel companies don't NEED to add ethanol, there are new synthetic additives to raise the octane rating (which is actually the effective isoctane rating, octane is actually the lower temp. burning crap that lowers the rating).

Anyway, ethanol isn't needed, because there are now cheap alternatives (actually cheaper, and I think better for the environment), but the congresspersons from the states that rely on corn (the source of ethanol) as a cash crop are lobbying to keep a regulation on the books that requires ethanol to be added to engines. The ethanol, I believe, does something to lower the ozone or carbon monoxide levels in gas, but harms the environment itself. I'll try to look that up in a chem. book that I have somewhere.

summing up - ethanol isn't needed, is worse than other additives, but politicians don't feel like having to deal with their constituents that make a living off of corn harvesting (or is it grain that ethanol comes from, the situation is the same if it's that).

[silviamirage]

ok, I looked at my chem. book (undergraduate environmental chemistry book, actually quite unbiased on issues). It said that gasoline bought in certain metropolitian areas that have pollution problems has to contain at least 2% oxygen (remember that compounds like ethanol and methanol contain oxygen) to reduce ozone and carbon monoxide levels (I don't remember how, want to research, but don't feel like having to explain it).Anyway, methanol can be used to this effect, and it's cheaper to produce by far, but the EPA (Environmental Protection Agency -don't let the name decieve you, they're beurocrats too), "ruled in 1994 that all oxygenated compounds used in reformulated gasoline must come from renewable (agricultural) resources.

Of course, there's a chance (according to the text) that ethanol releases more CO2 than methanol (which comes from petroleum), and it takes additional energy (including tractors and other equipment that pollute and use petroleum-based products. Also, someone posted in this thread that it causes condensation.

For the consumer, even the one that doesn't give a damn about the environment, this means that they have to pay more for their gas (ethanol costs considerably more than methanol, especially when the energy production is compared), and their cars may not run as well.

[silviamirage]

Sorry about my multiple posts, but one other thing-

Don't buy gas in a city with pollution problems unless you know that it doesn't have ethanol in it.

[Tino]

im right your wrong... LALALALALALALALA I CANT HEAR YOU!

[PalmerWMD]

A couple more pro's and cons

Of course, there's a chance (according to the text) that ethanol releases more CO2 than methanol (which comes from petroleum), and it takes additional energy (including tractors and other equipment that pollute and use petroleum-based products. Also, someone posted in this thread that it causes condensation..

-This is correct:There is more than a chance:Methanol= CH2OHEthanol= CH3CHOH

The 2 carbons on Ethanol result in 2 CO2's liberated on combustion whereas the 1 carbon in Methanol results in only 1 CO2.

However Methanol can also be made from agricultural sources just not as nearly cheaply as Ethanol, Ethanol is the easiest most direct way to make an alcohol form renewables.

-As for condensation.Both Ethanol and Methanol have the effect that they will reduce the water load on your gasoline, because they help keep it in solution, where it would otherwise be insoluble in gasoline (thus being free to rust things.Kinda like and automatic "heet" at every fill -up. -Methanol and Ethanol are not real friendly to gaskets and injectors.For example the injectors on a 300ZXTT and on a Q45 will last forever if they never see Methanol or Ethanol in the gas, but if they do see trhat a lot they will go kaput at 100k or thereabouts.

Fred...