What do u fuel ur car with?

[buhdda]

I'm just curious...because i normally go with 91, but i'm wondering if i go 93 does that mean i can for 89 and still average 91?

Also i have a friend who has a Acura RL 3.5 and he says he just puts the cheapest stuff in his ride

[auditech10]

Why not put better gas in your tank of a car that you really like and want to keep for some time??? What is the difference between the cheapest and the most expensive, 20-25 cents, right? So 20 gallons times 20-25 cents(20 X .20/20 X .25) equals 4 or 5 dollars. Im not sure about everybody's financial situation but if 4 or 5 dollars is hurting your wallet then you dont need this car to begin with.

[auditech10]

I wish I could find a video of this online, but last week or so I was watching the news(this rarely happens, lol) and they were doing a small segment on why people driving around to find the lowest priced gas around their area. They interviewed this guy at the pump and he said that he drove 15 miles out of his way to save 20 cents a gallon and his tank was 16 or 18 gallons. Well yeah he was saving $3.60 a tank but what about the 1.5 or 2.0 gallons that he spend going to this far away gas station. The kicker of this story is that the newsperson asked this guy what he did for a living. Guess what his answer was??? He was a financial advisor or accountant or something like that. The newsperson walked away laughing at this guy, as I almost had my morning glass of milk exit my nose, LOL

[91RMKS13]

That is funny.

[cremecreme]

That is a great point.....i only roll with premium...so i can get the maximum performance

[scjconsulting]

Here in Minnesota, it is hard to find 91 octane. It is usually 92 or 93.

[buhdda]

Auditech,

It's not the $5, but what the $5 is actually doing for me. When i get rims, or anyother mod i can see a difference i struggle with justfying 93 fuel because i'm unlcear on waht the differences are.

Do u get more gas mileage? Better enigine performace in terms of HP?

The only reason i put in 91 is because that is what is recommend in the manual. Also sometime i will go to a gas station and they wont have 93.

As for the ancecdote on the guy who drove 15 mile to save on gas, i dont think that is a fair comparison. Wasting time driving 15 mile is obviously inconvenient, but whether to push the 91 or the 93 button does not requirre more effort either way.

[auditech10]

Hey I meant no disrepect in any way if thats what anybody is thinking.The octane rating is a number based on the resistance to detonate, meaning that when compressed to a certain pressure, the air/fuel mixture will ignite BEFORE the spark plug fires. This can cause your engine to go capuut. Ok so Nissan says it recommends 91 octane, that is most likely because 93 is not found all across the US as some have said, but is it ok for you to use and have no problems? Yeah I would say that is ok as I have put cheaper gas in other cars that Ive driven that recommended the higher octane. BUT in the same respect, if spending the extra few bucks every fill up MIGHT prevent my engine from detonating sure why not. You would put the best tires you can afford on your car, right? Well I feel the same way and why not do the same for the gas? I drive my car alot and just having the piece of mind is worth it for me. That is just my opinion, take it however you will.Cheers

[jEzTeR]

93 for me as well.

[szh]

For the M35, Infiniti says that 87 is needed, but but 91 is recommended.

For the M45, Infiniti says that 91 is needed, but that you can get away with less if 91 is unavailable, but make sure to get back to normal later.

So, 93 is probably not needed, but that is what most states in the country have as Premium.

And, yeah, you could perhaps get away with using 89 or 87 in an M45, but this means that the electronics have to compensate for more than the design recommendations.

Plus, you could end up with bad gas ...

Finally, given typical driving miles, and typical gas costs, the difference between filling up with 87 and filling up with 91 is generally about $10 to $15 a month for most people.

Is saving this amount really important to a given M owner? If so, then you probably should have considered getting some other car that was less expensive, with better gas mileage, in the first place!

Z

[Q45tech]

The main factor to consider is the amount of amine detergents in regular vs premium...............as buying these detergents [techron, BG44k, etc] standalone will cost significantly more than paying the 20 cents per gallon premium to get them already blended into gasoline.

So called top tier just add the absolute legal minimum not enough to really clean things.

If you must alternate fill ups between reg and premium or use midgrade.

In hot summers or mountains you may notice differences in octane.

[buhdda]

The better gas mileage is an interesting issue.

I might have to test it out. Does 93 perform better than 91? If so by how much? Maybe after it is factor in 93 is not anymore expensive?

Has anyone actaully tested this out before?

[paigoomein]

I'm testing out using either 87 or 91 for gas as well, and I'm going to stick with using 91 (premium). you guys are right--it's about 15-20 cents more expensive per gallon. I get around 17-18 mpg using 87, and around 20-21 mpg using 91. Percentage-wise that's about 10% more miles per gallon. Seeing that 15-20 cents more per gallon is less than 10% of the cost of fue per gallon nowadays, it makes sense for me to fuel up with premium and treat my car better over the long haul.

[szh]

I'm testing out using either 87 or 91 for gas as well, and I'm going to stick with using 91 (premium). you guys are right--it's about 15-20 cents more expensive per gallon. I get around 17-18 mpg using 87, and around 20-21 mpg using 91. Percentage-wise that's about 10% more miles per gallon. Seeing that 15-20 cents more per gallon is less than 10% of the cost of fue per gallon nowadays, it makes sense for me to fuel up with premium and treat my car better over the long haul.

Z

[buhdda]

Quote »I'm testing out using either 87 or 91 for gas as well, and I'm going to stick with using 91 (premium). you guys are right--it's about 15-20 cents more expensive per gallon. I get around 17-18 mpg using 87, and around 20-21 mpg using 91. Percentage-wise that's about 10% more miles per gallon. Seeing that 15-20 cents more per gallon is less than 10% of the cost of fue per gallon nowadays, it makes sense for me to fuel up with premium and treat my car better over the long haul. [/quote]good info!!!

Has anyone tried a similar experiment between 91 and 93?

[paigoomein]

sorry, we only get 87, 89, or 91 octane where I am.

[szh]

sorry, we only get 87, 89, or 91 octane where I am.

Same here! California gas ...

Z

[SilverShadow]

Strange, the FTC seems to think as a rule higher octane fuel will not prevent, cleans or remove deposits any better than regualr octane fuel.

http://www.ftc.gov/bcp/conline....shtm

[buhdda]

yes but this is based on the average car that requires regular 87. Our car requires 91 so i would definitly not put 87/89 in it.

[SilverShadow]

Did you read the section in the link that talks about "Will higher octane gasoline clean your engine better?" that's what I was talking about. Don't see any mention as to 87 octane.
Modified by SilverShadow at 1:53 PM 4/24/2007

[cremecreme]

I use Jet Fuel......=)

[jgoodman]

I thought that all higher octane did was prevent pre-ignition. I have a buddy who is a chemical engineer for Shell Oil, and he says higher octane does nothing more than prevent pre-ignition. I have now been using 87 octane for a couple of months in my 2006 M35X and have not detected any performance drop. I'm and old fart, and am not drag racing it every day, but there is no knock, and no drop in fuel economy. I think maybe the on board computer detects octane differences and retards or advances the ignition as needed to prevent engine knock. If it has to retard the ignition to prevent knock, maybe you lose a little performance, but I don't think you are harming anything. Correct me if I'm wrong.

[auditech10]

Correct! But once the ECM detects knock it changes the timing as much as it can to prevent it from doing damage. There is no performance gain with using higher octane fuel but if there is knock with lower octane you will lose loads of power. Also, carrying heavier loads in your car(towing, etc) will promote more heat in your engine which in turn will promote pre ignition and detonation. Heat is the killer of all things, not enough is not good and too much is not good. Cheers

[buhdda]

jpgoodman,

I think a distinction u need to make is that for the m35 87 is ok, since it only requires 87. By the 45 requires 91

[telcoman]

I agree with you. I have a 2006 G35 6 sp manual and have used 87 octane since day one. I now have 26k miles and have never heard a ping or a knock. I am also an old fart and have been driving a manual shift for over 40 years. Very few vehicles require premium fuel and if you are not on a race track I feel it is a waste of money. Just my opinion!

Telcoman

[Nick240sx]

if these gas prices ever go down, ill start putting higher grade fuel in my car, for now its 87 cause thats all it requires. Running on higher octane however is better for the car and more efficient.

its 93 no matter what for the E63 though, pita!

[ddgsxr504]

I run 91 only cuz thats all this $hitty state of Kalifornia has to offer.

[Nick240sx]

I run 91 only cuz thats all this $hitty state of Kalifornia has to offer.

really? i did not know that

[szh]

really? i did not know that

Yes.

California has special gas requirements ... it would be too expensive for the the oil refineries to make 93 octane with that special formulation. Plus, given the extra tax burden in this state, most people would not buy it anyway, driving the price even higher (basic supply and demand).

Z

[Nick240sx]

Yes.

California has special gas requirements ... it would be too expensive for the the oil refineries to make 93 octane with that special formulation. Plus, given the extra tax burden in this state, most people would not buy it anyway, driving the price even higher (basic supply and demand).

Z

note to self. do not move to california.