About the whole octance grade issue - I don't get it!!!!!!!!
09-19-2003, 06:58 PM
#1
Guest
Posts: n/a
About the whole octance grade issue - I don't get it!!!!!!!!
Ok...after reading many posts on octane put in Maximas, I got very confused. I live in Chicago where the octance grades are 87,89, and 93. Some gas stations, however, carry something close to 100 octane. Can I get that? I asked that question a few times before and got different answers from everybody...WTF?
One time before going to a 1/4 dragaway, I told a few guys on the org that I might get higher octance gas before I go. One guy told me that I absolutely cannot get close to 100 octane gas for my 99 SE-L because it contains lead. I know Maxima is an unleaded only vehicle, but I read in many places that this is not necessarily correct. That is, high octane gas may or may not contain lead in it. The gas they sell at 1/4 dragaways and other locations close to my house sell 103 octane, which does contain lead. However, many regular gas stations which sell like 99 octane do not contain lead; hence, unleaded gas. My point is that many people don't know about this - just because octane grade is around 100, it does not mean that it does contain lead. I know cars in Japan run on 100+ octane, which is 100% lead free.
Others have told me that higher octane even without lead can be extremely harmful? I don't get it, why? I mean, the owner's manual says I can safely put anything from 91 to like 100 octane in my car, as long as it is unleaded. BTW, My Max is not Cali spec.
I know that all 4th gen and 5th Maximas were made in Japan, right? Well, I also know that in Europe 99 unleaded octane is as common as 93/94 here in the US.
Lastly, some have stated that higher octane gas in a Maxima will not boost performance. That's crap....how can it not? I heard many times that Maximas and other cars like the WRX are more powerful over seas just because of that. Also, many of the people I spoke with claimed that higher octane gas (98+) increased their performance dramatically.
Any comments?
One time before going to a 1/4 dragaway, I told a few guys on the org that I might get higher octance gas before I go. One guy told me that I absolutely cannot get close to 100 octane gas for my 99 SE-L because it contains lead. I know Maxima is an unleaded only vehicle, but I read in many places that this is not necessarily correct. That is, high octane gas may or may not contain lead in it. The gas they sell at 1/4 dragaways and other locations close to my house sell 103 octane, which does contain lead. However, many regular gas stations which sell like 99 octane do not contain lead; hence, unleaded gas. My point is that many people don't know about this - just because octane grade is around 100, it does not mean that it does contain lead. I know cars in Japan run on 100+ octane, which is 100% lead free.
Others have told me that higher octane even without lead can be extremely harmful? I don't get it, why? I mean, the owner's manual says I can safely put anything from 91 to like 100 octane in my car, as long as it is unleaded. BTW, My Max is not Cali spec.
I know that all 4th gen and 5th Maximas were made in Japan, right? Well, I also know that in Europe 99 unleaded octane is as common as 93/94 here in the US.
Lastly, some have stated that higher octane gas in a Maxima will not boost performance. That's crap....how can it not? I heard many times that Maximas and other cars like the WRX are more powerful over seas just because of that. Also, many of the people I spoke with claimed that higher octane gas (98+) increased their performance dramatically.
Any comments?
09-20-2003, 05:29 AM
#4
http://forums.maxima.org/showthread.php?t=72447
it is at the top of the page, it says" Sticky - 4th Gen FAQ's
it is at the top of the page, it says" Sticky - 4th Gen FAQ's
09-20-2003, 07:27 AM
#5
Senior Member
Join Date: Sep 2003
Posts: 118
As far as I know, it is illegal to sell leaded gas for on road automobiles.
Aviation gas is leaded (and high octane) and leaded gas sold at the 1/4 mile or autocross tracks is exempt from the general consumer category of auto fuels.
Your max won't benefit from 100 octane unleaded fuels,as it only has a compression ratio of 10:1 with aluminum heads and block. Aluminum does a better job of dissipating knock generating heat than the steel used in heads and blocks of days gone by. Aluminum allows you to be comparable to a steel head and block engine compression ratio of 1 point lower. In other words a 10:1 aluminum head and block car like the max is comparable to a 9:1 compression ratio in steel. Compression ratio is the single biggest factor in determining octane needs in a na car. 100+ octane gas is designed for cars with very high compression ratios like 13:1 to 16:1, or those running high boost turbos or superchargers.
Unless you run leaded fuel,running octane of 100 won't hurt your engine, it'll just be a waste of money.
I'd really like to see some dyno results on 4th gen Maximas, starting with 87 octane and working up to say 95 and find the point where there is no longer any performance improvement.
Aviation gas is leaded (and high octane) and leaded gas sold at the 1/4 mile or autocross tracks is exempt from the general consumer category of auto fuels.
Your max won't benefit from 100 octane unleaded fuels,as it only has a compression ratio of 10:1 with aluminum heads and block. Aluminum does a better job of dissipating knock generating heat than the steel used in heads and blocks of days gone by. Aluminum allows you to be comparable to a steel head and block engine compression ratio of 1 point lower. In other words a 10:1 aluminum head and block car like the max is comparable to a 9:1 compression ratio in steel. Compression ratio is the single biggest factor in determining octane needs in a na car. 100+ octane gas is designed for cars with very high compression ratios like 13:1 to 16:1, or those running high boost turbos or superchargers.
Unless you run leaded fuel,running octane of 100 won't hurt your engine, it'll just be a waste of money.
I'd really like to see some dyno results on 4th gen Maximas, starting with 87 octane and working up to say 95 and find the point where there is no longer any performance improvement.
09-20-2003, 10:02 AM
#7
Handsome
Join Date: Sep 2002
Posts: 2,074
High octane gas only makes it safer for your car to run more power, it doesn't actually provide more power (that is over the engines optimal octane, which for the max I would guess is 91-93.)
Let's say you are pushing 200hp to the wheels with boost. You start advancing the timing and uping the boost so that you can get 250hp, but there is a problem, you start to here detonation. So now you put hgh octane race gas in, this takes care of the detonation and allows you to advance timing further.
This is from my understanding the only benefits that race gas provides, it allows you to make more power safely.
Let's say you are pushing 200hp to the wheels with boost. You start advancing the timing and uping the boost so that you can get 250hp, but there is a problem, you start to here detonation. So now you put hgh octane race gas in, this takes care of the detonation and allows you to advance timing further.
This is from my understanding the only benefits that race gas provides, it allows you to make more power safely.
09-20-2003, 10:42 AM
#8
Originally Posted by SuperFishstick
a higher octane rating will allow the fuel mixture to burn cleaner ( that is if your plugs are in good shape) Since it burns cleaner none of the fuel gets left over , hence lower emisiions and more power.
09-20-2003, 10:50 AM
#9
Moderator who thinks he is better than us with his I30
iTrader: (8)
Join Date: May 2002
Posts: 9,335
Originally Posted by SuperFishstick
a higher octane rating will allow the fuel mixture to burn cleaner ( that is if your plugs are in good shape) Since it burns cleaner none of the fuel gets left over , hence lower emisiions and more power.
This is why we need to run a higher octane.
Fuel is made up of several hydrocarbons, octane being one of them. Octane resists spontaneous combustion better than the other hydrocarbons. With a fairly high compression engine, like the VQ30de, it is easy to have pre-ignition when running a low octane fuel. You don't want the air-fuel mixture to ignite befor the spark is present. A higher octane will help prevent this.
Since we have knock-sensors we can use low octane fuel and the car still run fine. When pre-ignition is detected the ECU will retard the timming to compensate. With the timming retarded the car will not perform as well.
09-20-2003, 11:09 AM
#10
I use Mark 5 by Pro Racing Fuels, http://www.speedwaybikes.com/sponsors/fuel.htm it is 114 octane unleaded. I don't believe you can get any higher octane unleaded than that.
Don't use it if you are N/A it will degrade your performance dramatically unless you change your timing, plugs, A/F etc and even then it may not make it quicker. Plus you are wasting your money for the small advantage it may give. The reason I use it is not so much for performance but to reduce the possibilty of knock and detonation.
Don't use it if you are N/A it will degrade your performance dramatically unless you change your timing, plugs, A/F etc and even then it may not make it quicker. Plus you are wasting your money for the small advantage it may give. The reason I use it is not so much for performance but to reduce the possibilty of knock and detonation.
09-20-2003, 11:30 AM
#12
Handsome
Join Date: Sep 2002
Posts: 2,074
Originally Posted by ivelweyz
BOSS they sell 100octane at a clark station out in Naperville on Irving Park right by the train tracks. I bought a couple gallons when I was on empty. The car was faster and more responsive but I wouldn't buy a whole tank of it...
09-20-2003, 11:48 AM
#13
Moderator who thinks he is better than us with his I30
iTrader: (8)
Join Date: May 2002
Posts: 9,335
Originally Posted by ivelweyz
BOSS they sell 100octane at a clark station out in Naperville on Irving Park right by the train tracks. I bought a couple gallons when I was on empty. The car was faster and more responsive but I wouldn't buy a whole tank of it...
09-20-2003, 12:22 PM
#15
Senior Member
Join Date: Aug 2002
Posts: 663
Originally Posted by I30tMikeD
That is really not correct, well it is, but that is not why we need to use a higher octane gas. Your right that higer octane gas may burn cleaner, but that is because it usually contains more detergents. That is not the reason we need to use it though.
This is why we need to run a higher octane.
Fuel is made up of several hydrocarbons, octane being one of them. Octane resists spontaneous combustion better than the other hydrocarbons. With a fairly high compression engine, like the VQ30de, it is easy to have pre-ignition when running a low octane fuel. You don't want the air-fuel mixture to ignite befor the spark is present. A higher octane will help prevent this.
Since we have knock-sensors we can use low octane fuel and the car still run fine. When pre-ignition is detected the ECU will retard the timming to compensate. With the timming retarded the car will not perform as well.
This is why we need to run a higher octane.
Fuel is made up of several hydrocarbons, octane being one of them. Octane resists spontaneous combustion better than the other hydrocarbons. With a fairly high compression engine, like the VQ30de, it is easy to have pre-ignition when running a low octane fuel. You don't want the air-fuel mixture to ignite befor the spark is present. A higher octane will help prevent this.
Since we have knock-sensors we can use low octane fuel and the car still run fine. When pre-ignition is detected the ECU will retard the timming to compensate. With the timming retarded the car will not perform as well.
09-20-2003, 12:32 PM
#16
Guest
Posts: n/a
Coming from chicago I take Irving park, around ohare, and go til I get to the train tracks. On the left is shell on the right is clark. Only one pump has 100 octane though. It's the one right across from the convenience shop, 3rd row from the street...
09-20-2003, 12:42 PM
#17
Moderator who thinks he is better than us with his I30
iTrader: (8)
Join Date: May 2002
Posts: 9,335
Originally Posted by ivelweyz
Coming from chicago I take Irving park, around ohare, and go til I get to the train tracks. On the left is shell on the right is clark. Only one pump has 100 octane though. It's the one right across from the convenience shop, 3rd row from the street...
09-20-2003, 12:46 PM
#18
Senior Member
Join Date: Sep 2003
Posts: 118
Originally Posted by mzmtg
Nope. Not even close.
Then, he is right. This assumes he's comparing to a low octane gas that causes preignition.
09-20-2003, 04:01 PM
#19
Guest
Posts: n/a
Originally Posted by I30tMikeD
You take a city street from O'hare to Naperville???? That would take forever
09-20-2003, 10:17 PM
#20
Moderator who thinks he is better than us with his I30
iTrader: (8)
Join Date: May 2002
Posts: 9,335
Originally Posted by ivelweyz
Sorry guys I got it messed up. I always confuse Naperville with Bensenville. I apologise again guys, sorry. It's right on york and Irving park. Sorry for the confusion, and the last time I checked it was only 10 cents more than 93 octane...
Hahahha, I figured you were thinking of a different town. I was like WTF, why don't you just take the tollway to Naperville.
09-21-2003, 05:38 AM
#22
i think slammed95 is correct. i remember reading that really high octane gas loses performance from Daniel B. Martin . he also said this. just mix 93/94 with 89 and u will have 91 and that is exaclty what the factory recamends so u get the most performance.
09-21-2003, 09:35 AM
#26
From user manual -
---------------
"FUEL RECOMMENDATION:
Unleaded premium gasoline with an octane rating of at least 91 AKI number.
If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 87 AKI can be used.
However, for maximum vehicle performance, the use of unleaded premium gasoline is recommended."
----------------
---------------
"FUEL RECOMMENDATION:
Unleaded premium gasoline with an octane rating of at least 91 AKI number.
If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 87 AKI can be used.
However, for maximum vehicle performance, the use of unleaded premium gasoline is recommended."
----------------
09-21-2003, 12:18 PM
#30
Guest
Posts: n/a
Originally Posted by mzmtg
The owners manual specifies and AKI of at least 91.
Is it even worth the 80 cents to mix 93 with 89. It's a 10 cent difference in price, split 8 gallons each and you save 5 cents a gallon. What's the point???
09-21-2003, 12:29 PM
#31
09-21-2003, 03:12 PM
#32
You guys want to save like 3 bucks a fillup by using 87 octane gas? 87 octane will probably give less MPG (for me it did) and in the end you'll be spending almost the same amount of money for gas... Here's my result:
::87 octane::
15 gal fillup x $1.77 = $26.55 for fillup
16.5 MPG x 15 gal = 247.5 miles which is ~$.1073 a mile
::93 octane::
15 gal fillup x $1.97 = $29.55 for fillup
18.8 MPG x 15 gal = 282 miles which is ~$.1048 a mile
I also get 5% back from Shell so it'll be a little bit more cheaper than these results, but it seems cheaper to use premium for me, not sure about you 
::87 octane::
15 gal fillup x $1.77 = $26.55 for fillup
16.5 MPG x 15 gal = 247.5 miles which is ~$.1073 a mile
::93 octane::
15 gal fillup x $1.97 = $29.55 for fillup
18.8 MPG x 15 gal = 282 miles which is ~$.1048 a mile
I also get 5% back from Shell so it'll be a little bit more cheaper than these results, but it seems cheaper to use premium for me
, not sure about you
Thread
Thread Starter
Forum
Replies
Last Post