Choice of gasoline

I would not use non-premium gasoline in a car designed to use premium. As noted in the owner's manual, using lower pump octane than the recommended 91 will degrade performance. Performance means not only acceleration, but also gas mileage - and reduced gas mileage will more than offset the cost savings of a few cents per gallon. Don't do it. (Except in an emergency, if regular or mid-grade are the only fuel you can find before you run out of gas.)
 
You may ask GOBBLE...I think he uses diesel, or he may tell you that..... :biggrin:

I use whatever is rated 91 Premium (Californias Highest) at whatever
gas station is around when I get down to 1/8 of a tank.

It's normally about 2.89 /gal (Californias Prices)
 
In Japan, they have 100 to 103 or so as Premium. (and 94 as regular I think?)

pretty cool eh :biggrin:
 
oh by the way, you have to use 91 octane at least.

You will end up getting some carbon in your engine, which cause some serious damage. If you're keep using something lower than 91 octane, the severe knocking will result. No Joke.
 
Timpo said:
In Japan, they have 100 to 103 or so as Premium. (and 94 as regular I think?)

pretty cool eh :biggrin:
Japan and Europe use different measures of octane. Here in North America, pumps are labeled using (RON+MON)/2, which is properly called the "anti-knock index". If I'm not mistaken, other markets use RON, which is higher than MON or our (RON+MON)/2.

You can read more about gasoline octane and what it means in Part 3 of the Gasoline FAQ.

Timpo said:
oh by the way, you have to use 91 octane at least.

You will end up getting some carbon in your engine, which cause some serious damage. If you're keep using something lower than 91 octane, the severe knocking will result.
Not true. The NSX owner's manual notes that the car's electronics will make the necessary adjustments so that no damage will be done to the engine from using lower octane fuel.
 
nsxtasy said:
Performance means not only acceleration, but also gas mileage
I think this depends on what kind of driving you're doing. I regularly do 400 mile trips on straight, flat roads and over the last 4 years I mostly run regular fuel for these trips and haven't noticed any change in fuel economy. And I don't think you need to be burning premium fuel to maintain a steady 60 mph at 2600 RPM without knocking or retarding timing...on flat, straight roads.

That said, around town I almost always use mid-grade and rarely run premium unless I intend on some spirited driving. I've also tried Ethanol blends with mixed results. The first tank or two was ok but then the check engine light came on intermittantly so I went back to non-Ethanol blends and things went back to normal
 
NsXMas said:
imho, if you buy an NSX, and use less than 91 octane in it, you should reconsider why you bought an NSX in the first place.
I agree. It amazes me that people spend oodles of money to buy a high-performance supercar, and then degrade its performance in order to save a few bucks on gasoline, tires, etc.
 
I have been using regular gas for my BMW 330 and Lexus RX330 for years.Both of which needs premium gas as stated in the owner's manual. I have never encountered knocking or engine light turning on. Most modern day engines are electronically controlled to adjust accordingly with different grades of gas.
If you are on the track,then I think every drop of power counts. Everyday driving is hard to notice the difference.
 
NsXMas said:
imho, if you buy an NSX, and use less than 91 octane in it, you should reconsider why you bought an NSX in the first place.

I know it only comes out to be a few hundred dollars more a year. Not a big deal. Just flooring the throttle a few times a day can waste as much as you can save. I was just thinking is the lower octane rating really bad for the car if the manual suggest premium grade? Any scientific study to prove that?
 
fannsx said:
I know it only comes out to be a few hundred dollars more a year.
Not even. The difference is probably less than a hundred dollars. If you drive 10,000 miles a year in your NSX (which is double the average for NSXs), you're probably using about 500 gallons. With a difference in cost between grades of gasoline of 10-20 cents, that's only $50-100.

fannsx said:
I was just thinking is the lower octane rating really bad for the car if the manual suggest premium grade? Any scientific study to prove that?
If you need a scientific study to prove that what your owner's manual tells you is best for your car, then, like Frank says, you never should have bought the car in the first place. You're much better off buying a cheap, "disposable" car if you're not going to take care of it according to the manufacturer's recommendations.
 
nsxtasy said:
Not even. The difference is probably less than a hundred dollars. If you drive 10,000 miles a year in your NSX (which is double the average for NSXs), you're probably using about 500 gallons. With a difference in cost between grades of gasoline of 10-20 cents, that's only $50-100.

If you need a scientific study to prove that what your owner's manual tells you is best for your car, then, like Frank says, you never should have bought the car in the first place. You're much better off buying a cheap, "disposable" car if you're not going to take care of it according to the manufacturer's recommendations.

I LOVE MY CAR. You are getting off the topic and my original question.

Just because breast milk has been proven to be better than formula, not everyone grew up with breast milk. I am sure that has nothing to do with how much they love their babies.

I just don't know what so bad about lower octane gas if the car does not knock,beside losing a little power. I will probably always use premium on my NSX.

The term "disposable car" is relative. NSX can be diposable( not to me of course) like the 360 Modena that the guy drove into a wall in the movie clip on one of the threads. --------------------------------------------------------------------------------

http://www.big-boys.com/articles/badredcar.html
 
fannsx said:
I have been using regular gas for my BMW 330 and Lexus RX330 for years.Both of which needs premium gas as stated in the owner's manual. I have never encountered knocking or engine light turning on. Most modern day engines are electronically controlled to adjust accordingly with different grades of gas.
If you are on the track,then I think every drop of power counts. Everyday driving is hard to notice the difference.
Lots of car companies reccomend 91, but a few require it. Its a simple fact, the car is tuned to run a minimum amount of octane. Most American sold cars can run 89, but not super-high end performance ones.
As a result of its high compression and tunning, the nsx NEEDS 91 at a bare minimum. Will running less damage your engine?
probably not, the nsx has a knock sensor that can change the timing so your car doesnt knock. but it runs like crap, which brings us full circle to the question of why you're driving an nsx in the first place?
 
paladin said:
the nsx has a knock sensor that can change the timing so your car doesnt knock. but it runs like crap, which brings us full circle to the question of why you're driving an nsx in the first place?

I can hardly believe it will run like crap. Besides I dont know what you mean by crap.
I drive NSX because I like the car and always wanted one since 1991.

I dont take it to track,at least not yet. I still have a lot to learn about track driving and car performance.I know I am way behind some of you guys in knowledge of NSX or performance vehicles. But many of us get the NSX for different reasons.
 
fannsx said:
I can hardly believe it will run like crap. Besides I dont know what you mean by crap.
I drive NSX because I like the car and always wanted one since 1991.

I dont take it to track,at least not yet. I still have a lot to learn about track driving and car performance.I know I am way behind some of you guys in knowledge of NSX or performance vehicles. But many of us get the NSX for different reasons.

I say run like crap because it has to. if you encounter knock your car can do one of two things. keep knocking and ruin your motor, or change the timing so it can limp along
 
lol, um... with the compression that we use in our engine, its not just a suggestion, its a stated requirement, as an engineer by profession i can definitely say that in general minimum requirements are not there just for show, they are always warrented for some reason (sometimes for non-obvious ones you can think of) granted i'm sure the design is robust enough that it may 'still work' but may not work as intended, also there are other types of pre-ignition / detonation other than the type that you can hear 'ping' 'ping'. there is such thing as a silent detonation (silent killer) that you would only be able to pick up using a Exhaust Gas Temperature sensors.
usually the knock sensors are microphones that pick up the 8khz-ish knock frequency, but for other types of knock this isnt necessarily always accounted for. i mean i'm sure that some cars that just happen to be on the good side of the statistical curve can run happy all day with lower than said requirements gasoline, but i dont know if i'd like to press my luck on my car,
just my humble opinion :biggrin:
 
Hydrocarbon_101

fannsx said:

hmmm... Mr fannsx, you need to read up on what octane exactly is & how different octane levels in particular grades of gasoline are specifically meant for certain engines. It's not a matter of performance or track-use to have atleast 91 octane fuel for your NSX. The NSX engine is a higher compression motor, and the higher octane level in the gasoline allows the fuel to undergo a higher degree of pressure before it ignites. You can almost think of octane as an 'impurity' that retards the combustion process at lower pressures.

Once you've understood what octane actually is in relevance to different grades of fuel, and also why the NSX engine needs a certain octane... you'll be keen to make sure atleast 91 octane is always used!

Andy Vescey is a petroleum engineer (I believe) and he has offered many insights regarding gasoline/fuel, search some of the posts he has made in the past!
 
fannsx said:
...is the lower octane rating really bad for the car if the manual suggest premium grade? Any scientific study to prove that?
You might want to look at http://www.mr2.com/TEXT/gasoline_faq.txt which I found in an earlier Prime post and seems to be quite detailed and quotes a lot of sources.

Although it clearly warns about the dangers of knock, it does make the following comment: "You should initially be guided by the vehicle manufacturer's recommendations, however you can experiment, as the variations in vehicle tolerances can mean that Octane Number Requirement for a given vehicle model can range over 6 Octane Numbers. .... You can often reduce the octane of the fuel you use in winter because the temperature decrease and possible humidity changes may significantly reduce the octane requirement of the engine."

So I prefer to conclude from this link that the octane your engine requires isn't an absolute number (as others have earlier tried to suggest), it's somewhat variable based on things like engine load and ambient air conditions.

Clearly anyone who can afford an NSX can afford to put premium fuel in it but I'm an engineer by training (and a contrarian by nature) so I tend to question everything and like to test the limits ... as evidenced by the fact that I decided to buy a (1) high mileage, (2) tracked NSX and (3) daily drive it (4) year round including (5) extremely cold winter conditions... and many of those actions have in the past attracted uninformed naysayer comments similar to what your post has done. Never stop being inquisitive. Avoid being a lemming.

nsxtasy said:
...It amazes me that people spend oodles of money to buy a high-performance supercar, and then degrade its performance in order to save a few bucks on gasoline, tires, etc.
Ken, don't assume that because we all bought a "high-performance supercar" that we all use it to the limits to which it was designed. I happen to use mine as a "great-looking daily driver" and, as such, to me it is still worth everything I paid for it. But just as you wouldn't waste money putting 93 octane in it instead of 91, I choose to not waste money putting 91 in it when I feel it isn't req'd.
 
lol DIET MOUNTAIN DEW
EX-TREME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
lol
 
NSX2398 said:
You might want to look at http://www.mr2.com/TEXT/gasoline_faq.txt which I found in an earlier Prime post and seems to be quite detailed and quotes a lot of sources.
Which just happens to be exactly the same document as the link that I posted above.

NSX2398 said:
Ken, don't assume that because we all bought a "high-performance supercar" that we all use it to the limits to which it was designed.
I don't. But I do assume that no one buys an NSX in order to risk damage to an engine which will cost anywhere from $5K to $25K to replace. Especially when it's just so that they can save a buck or two on a thirty or forty dollar tank of gasoline. The recommendation in the NSX owner's manual, which was written with input from the engineers who designed the car, is very clear:

"Your NSX is designed to operate most effectively on premium unleaded gasoline with a pump octane number of 91 (research octane number of 96) or higher. If you are unable to find premium unleaded gasoline, an unleaded regular may be substituted. The engine will compensate for the lower octane, but you may notice a decrease in power as a result."

The manual tells you to use premium, NOT that this is in any way optional. The only condition under which it permits using non-premium is if you are unable to find premium unleaded gasoline, and no other circumstances.

In fact, if I were shopping for a used NSX, I would make sure that the seller took immaculate care of his/her car - and at a minimum that includes following Honda's recommendations for scheduled maintenance, proper fuel, etc. (Let's face it, a fastidious owner would never worry about saving a dollar on a tank of gas!) I would pass on a car where the owner didn't follow those recommendations, and such a car would likely be tougher to sell and might be worth a lower market value.

If you want to take good care of your car, follow the advice in the owner's manual, including the proper fuel and the scheduled maintenance and the other recommendations. (Of course, it's your car, and you can do whatever you want; after all, you're the one who will be responsible for paying for any damage, or decrease in market value, if you ignore that advice.) I like how Brent put it:

Brent95M3 said:
Dude, you have 3 high dollar cars, NSX, 330xi, and a new Lexus. This shouldn't be a topic of discussion. Buy f--in premium.
 
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I have a .40 cal handgun.....every once in a awhile I shoot .9mm thru it,

the manual specified .40 ammo only, but I figured it couldn't hurt :biggrin:
 
Besides using the correct grade of gasoline for the NSX which is premium of course, I only use gasoline which is certified as Top Tier. In my area Chevron is the most convenient to buy.

TOP TIER Detergent Gasoline is a recently established new standard for gasoline performance. Four of the world's top automakers, BMW, General Motors, Honda, and Toyota recognize that the current EPA minimum detergent requirements do not go far enough to ensure optimal engine performance.

Since the minimum additive performance standards were first established by EPA in 1995, most gasoline marketers have actually reduced the concentration level of detergent additive in their gasoline by up to 50%. As a result, the ability of a vehicle to maintain stringent Tier 2 emission standards have been hampered, leading to engine deposits which can have a big impact on in-use emissions and driver satisfaction.

These automakers have raised the bar. TOP TIER Detergent Gasoline help drivers avoid lower quality gasoline which can leave deposits on critical engine parts, which reduces engine performance. That’s something both drivers and automakers want to avoid.
 
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