Why 91 Octane????

[addicted2thevr6]

Okay, i have been hearing a lot that i need to be using 91 octane in my VR6. I was wondering why i should do this. what difference does it make? How does it help my engine? sound differently? let me know:confused:

[01rdGOLF]

91 octane= cleaner burning gas=less residue on your injectors=a lil more "umph" in your spirited driving. :)

[Ivan]

Totally wrong.
I don't know what octain your engine needs but the only
reason to use higher octain is to reduce detination.
Higher octain does no mean cleaner fuel.

Check your manual or call the dealer on what octain you need. If you used 92 and you really just need 87 it won't do you any good. Only waste your money. :smokem:

[SoCal_GLI]

Totally wrong.
I don't know what octain your engine needs but the only
reason to use higher octain is to reduce detination.
Higher octain does no mean cleaner fuel.

Check your manual or call the dealer on what octain you need. If you used 92 and you really just need 87 it won't do you any good. Only waste your money. :smokem:


no watercooled VW is meant to run on anything less than 92 octane, every motor VW makes suggests 92 octane.

it has to do with compression ratios...will it run on 87 octane?, yes it will....it will run better with 92....and 92 octane does burn cleaner due to the fact it needs to get hotter to combust

[Tom (aka Godzilla)]

Also, many gas refiners save the best additives for the 91 octane stuff. So, in certain circumstances, it is cleaner out of the nozzle.

[car]

Also, many gas refiners save the best additives for the 91 octane stuff. So, in certain circumstances, it is cleaner out of the nozzle.

as in shell, texaco (same thing), mobil, exxon....

but you can forget about getting anything worth while in ampm or joes gas station 91 octane...

[Ivan]

Gas all comes from the same tap, then the shell or who ever put there own "cleaner" in. They don't just save the "best" additives for 91. All octain levels get the same crap.

If factory sez to use 92, use 92. It's kinda hard to get though. I've never seen a 92 pump. Not for years anyways. lol
How do they expect us californians to meet factory standers?

[vtecwho]

I've never seen a 92 pump. Not for years anyways. lol
How do they expect us californians to meet factory standers?

go to another state and you will see higher octains, washington state has 94 and AND you can go to a TRICK station and get 100+ :eek: octain. :tup:

and i do believe california has lower octains because it has something to do with all the emissions. :confused:

[addicted2thevr6]

who cares about emissions, i want more horsies

[SYNYSTAGLI]

I have a N02 kit for sale :) 300 dollars will get you either 60, 80, or 120 shot....will add quite a bit of ponies for ya

[Troike]

no watercooled VW is meant to run on anything less than 92 octane, every motor VW makes suggests 92 octane.

it has to do with compression ratios...will it run on 87 octane?, yes it will....it will run better with 92....and 92 octane does burn cleaner due to the fact it needs to get hotter to combust

I've never heard this ... you have any proof? I could have sworn my manual (2.0L) says to use 87 ... and I've heard using anything more does no benefit, only costs more (and can even cause premature detonation or something)?

If 89 were $2.00 or less I'd use that, but its not, so I'm still chugging along with 87 ... car seems to run fine :p

[addicted2thevr6]

I have a N02 kit for sale :) 300 dollars will get you either 60, 80, or 120 shot....will add quite a bit of ponies for ya
is everything i need in the kit? and how many ponies? i dont know if its worht it

[jross]

go to another state and you will see higher octains, washington state has 94 and AND you can go to a TRICK station and get 100+ :eek: octain. :tup:

and i do believe california has lower octains because it has something to do with all the emissions. :confused:

There are 100 octane stations in Cali, you just need to look near racetracks.

[bugzy]

El Paso exit (Mission Valley) off 5 freeway in South OC has 100 oct pump at the 76 gas station

its usually $5/gallon

[SYNYSTAGLI]

is everything i need in the kit? and how many ponies? i dont know if its worht it

Well the kit comes with everything it was sold with from the factory, and I'm adding a N02 gauge, and a purge kit. As far as HP numbers, I'm not an expert *lil pun* but you will have a significant bump from what you have now using just the 60 shot...all ya have to do is put on your imagination cap and feel the G Forces with the 80, or 120 shot :eek: :eek:
trust me man, it's worth it. Try and find a N02 kit for 300.00 + gauge + purge kit

the purge kit will need a new solenoid as the previous owner in his haste to remove the kit broke a connector inside the solenoid. It can be removed but I would just replace it and to be honest with you, I'd replace all 3 being the kit hasn't seen nitrous for over 2 years now.

[05GLI]

El Paso exit (Mission Valley) off 5 freeway in South OC has 100 oct pump at the 76 gas station

its usually $5/gallon



But I don't think you can pump it strait into your car........ Can You?

[Fritz]

the higher the octane rating of the fuel, the slower it burns. the slower the burn the farther you can advance your timing. thats where you get the power from, a lean, cool burning fuel/air mixture with lots of time for it to burn. but you need to have software to change the mapping of the engine to maximize the use of higher octane. to just put 91 in a car that is factory programmed to use 87 will do nothing.

[mitssn]

Any watercooled VW I've ever seen is 91 octane minimum to include the VR6 and 1.8t

[blackSDSUjetta]

its actually the la paz exit in mission viejo in S. OC that has 100 octane at the pump at the 76

[addicted2thevr6]

Well the kit comes with everything it was sold with from the factory, and I'm adding a N02 gauge, and a purge kit. As far as HP numbers, I'm not an expert *lil pun* but you will have a significant bump from what you have now using just the 60 shot...all ya have to do is put on your imagination cap and feel the G Forces with the 80, or 120 shot :eek: :eek:
trust me man, it's worth it. Try and find a N02 kit for 300.00 + gauge + purge kit

the purge kit will need a new solenoid as the previous owner in his haste to remove the kit broke a connector inside the solenoid. It can be removed but I would just replace it and to be honest with you, I'd replace all 3 being the kit hasn't seen nitrous for over 2 years now.

yea uhhhh not in two years huh. i will have to think about that one.... you arent going to let the expert thing go huh? hahaha jerk;)

[SYNYSTAGLI]

yea uhhhh not in two years huh. i will have to think about that one.... you arent going to let the expert thing go huh? hahaha jerk;)

Ok, I'll keep the damn thing and we can go at it @ qualcomm. I will race your VR6 for....shall we say....50.00 :D And I'll even use the OLD solenoids ;) Just a friendly race between 2 experts :tup: and I won't put in in my VR..ahem my wifes VR, I'll bottle feed the Bunny :eek:

[veedubber7]

Just a friendly race between 2 experts

:ha:

[addicted2thevr6]

dude a friendly race for 50.00? how about we race and then you can buy me dinner. hahaha what kind of car do you have? i am sure i am the expert on it. i go down to qualcom for the fball games, press box baby, all the good free food in the world. i gain about 10 pounds each game i go to.

[daygoVR6]

this has aloways bee a huge controversory between imports and hot rodders alike, countless magazines have all done articles on which is better and it all comes down to the same thing ....(keep in mind these are all primedia publications)

92/91 octane is a waste of money in most modern day engines unless it is an engine with a high compression ratio (in which case the VR6 has about a 10:1, like my 12 valve) or like in many of the muscle cars (corvettes, mustangs, ect ect)

Most engines today are so advanced from the factory to run under normal driving conditions and even when your out "playing" in the car that you can get away with 87 (keep in mind this is with a stock motor with very lil to no mods, and the average compression ratio being about a 9:1 on most cars on the road today)

In many cases people think going with a higher octane will give you instant extra HP when in most cases you wont actually notice the difference unless you are on a dyno, or at a drag strip and you can actually see the difference in the numbers (i have alot of drag strip expirence with higher octane in my dub and other vehicles ive owned all showing about a tenth to maybe 2 tenths of a drop in ET)

The same goes for race fuel ive seen too many innocdents where someone has gone out and used 100+ (really funny after about 4-5 runs and the valves are toast)

Granted higher octane in a vehicle that does have a higher then average compression ratio in the cylinders (10:1 and up) will benifit from the use in high octane numbers from the pump other wise keep with 87 fgor the mileage and keep up on the upkeep of the motor (air filter, spark plugs, oil changes ect ect)


Hey Addicited i use 87 in my 12 vavle on the street but if im on the juice or at the track i do use something a lil higher because of the higher RPM usage and extra cylinder pressures when im on the squeeze

[SYNYSTAGLI]

dude a friendly race for 50.00? how about we race and then you can buy me dinner. hahaha what kind of car do you have? i am sure i am the expert on it. i go down to qualcom for the fball games, press box baby, all the good free food in the world. i gain about 10 pounds each game i go to.

lol, buy you dinner?? :confused: I have a 1984 4 banger (4 pistons) Rabbit GTI. I work for Qualcomm and most of my works events are in the press box, beer, sushi, dogs, burgers, da works. And yea, it's easy to put on some weight :D

[daygoVR6]

hahaha what kind of car do you have? i am sure i am the expert on it.


here we go ......:rolleyes:

[addicted2thevr6]

lol, buy you dinner?? :confused: I have a 1984 4 banger (4 pistons) Rabbit GTI. I work for Qualcomm and most of my works events are in the press box, beer, sushi, dogs, burgers, da works. And yea, it's easy to put on some weight :D
hahha yea buy me dinner, 4 banger huh? i am sure you have something in there or whatnot, who knows. i dont have 50 bucks to blow though dude, otherwise i would. my gf is in san diego so i am there fairly often.

[daygoVR6]

im just curious which VR6 are you using?

[vtecwho]

im just curious which VR6 are you using?

who you askin manni has a mk4 vr 24v (sorry manny you wifes now. :D )

and the expert has a 12v vr mk3

and yes the bunny will win all motor. :tup: ... :smokem:

[1.8T]

This might lend some insight to the debate. Below is a test done on the dyno.


http://www.caranddriver.com/article.asp?section_id=4&article_id=3604&page_number=1

[addicted2thevr6]

Ok, I'll keep the damn thing and we can go at it @ qualcomm. I will race your VR6 for....shall we say....50.00 :D And I'll even use the OLD solenoids ;) Just a friendly race between 2 experts :tup: and I won't put in in my VR..ahem my wifes VR, I'll bottle feed the Bunny :eek:

say i did come down to race..... would it be like an autocross kinda thing, or what?

[PDVR6]

say i did come down to race..... would it be like an autocross kinda thing, or what?

I think they are talking about drag racing, but what you should do is bring your car out to the next Racerfactory (http://www.racerfactory.com) event march 19 and 20 in pahrump nevada.

[Troike]

This might lend some insight to the debate. Below is a test done on the dyno.

http://www.caranddriver.com/article.asp?section_id=4&article_id=3604&page_number=1

good read ... I guess these parts apply most to me:

Conversely, in some engines designed for regular fuel, you can advance the timing if you burn premium, but whether this will yield additional power varies from engine to engine....

But, noted Schiller, only a few vehicles calibrated for regular fuel can advance timing beyond their nominal ideal setting when burning premium....

We should note that even cars designed to run on regular fuel might require higher octane as they age.

or most cars there is no compelling reason to buy more expensive fuel than the factory recommends, as any performance gain realized will surely be far less than the percentage hike in price.

My engine is quite high compression for a NA 4-cyl (10.0 I think!?) but seeing as it has run fine on 87 so far, and I'm poor, 87 will continue to flow into the tank until I get rich, we take over the Middle East, or I chip it.
At least I use name-brand gas (usually Chevron). Probably little difference, but I don't trust those boarded-up places with rusted-out pumps which dot 66.

[anderson]

Hey,

I always use the 91 octane gas at least and I think it´s way more expensive here in Germany ( 1,24 Euro a Litre!) cause i chipped it. Some of my friends fill in the 98 or even the 99 octane gas (1,30 a Litre) because they say, they can drive up to 50k´s more with it, but nobody can explain why, so I don´t trust it. Anyway, if you don´t have any problems with the regular gas, go on. But if you´re going to chip it, I would always use, what the tuner told you to fill in! They know, what they are talking ´bout.

Greetz from frosty Germany

Anderson

[addicted2thevr6]

^^wow you really scrounged this thread up from soooo long ago

[b-mo]

So, you meen to tell me I have been decieved for all these years into putting 91 (92 when available) in my factory spec vehicles? I feel so used.:( Well, at least I learned something.

[Bierbau]

Hey,

I always use the 91 octane gas at least and I think it´s way more expensive here in Germany ( 1,24 Euro a Litre!) cause i chipped it. Some of my friends fill in the 98 or even the 99 octane gas (1,30 a Litre) because they say, they can drive up to 50k´s more with it, but nobody can explain why, so I don´t trust it. Anyway, if you don´t have any problems with the regular gas, go on. But if you´re going to chip it, I would always use, what the tuner told you to fill in! They know, what they are talking ´bout.

Greetz from frosty Germany

Anderson

My friend is in Stuttgart right now with the Army. Are you in the service over there or are you a Native Deutschlander.

[wolfsjetta01]

i used to work at Huntington 76 In San Marino, we had 100 octane at the pump. loved seeing the farrari's and the lambos that filled up there.

[wErO]

the 91 octane gass just prolong your motor life thats all the difference!

[vr6gtiguy]

i only run 91, call it a waste of money, but in my bike if i run less i get a ping noise, an in my 98 vr6 gti it hesitates on less, an the same responce in my bimmer..... eh, i spend the money an jus enjoy the ride lol. oh, an side note, its like 30's here in oregon where im at right now, AND, i dont have to pump my own gas, they have an atendant to do that lol

[xXJakeXx]

I feel a difference with 91 in my mk3 98 2.0, seems to idle nicer and the engine purs along with a feel that i go faster. I dunno what i should be filling up with since its unchipped. but most of the time i run 89 in it.

[Skwurlz]

the higher the octane rating of the fuel, the slower it burns. the slower the burn the farther you can advance your timing. thats where you get the power from, a lean, cool burning fuel/air mixture with lots of time for it to burn. but you need to have software to change the mapping of the engine to maximize the use of higher octane. to just put 91 in a car that is factory programmed to use 87 will do nothing.

Your were absolutely correct until your last statement. Whether or not your car has parts or mods to take advantage of the physics of the burning higher octane doesn't matter, it's still burning more efficently. If you have a stock car, with no aftermarket stuff and you have been using 87, you WILL feel a difference with 91. The car will run smoother, your MPG will improve and your temp will be 1-2 degrees lower.

The higher the octane, the better it is for your engine, period. Granted you may not take full advantage of all the potential of the higher octane without setting your engine up for it, but it isn't going to hurt anything but your wallet.

For an example, my motorcycle (2000.5 Aprilia RSV) must run a minimum of 91 octane. I get around 42 mpg @ $2.75 per gallon and 118 RWHP (dyno proven).

Well about 3 months ago I started using 100 octane, as there is a local gas station that has it at the pump (unleaded still) With the 100 octane it's at 53 MPG and 133 RWHP ( again Dyno proven) Granted it is hard to stay out of WOT, but if I run it normal I am getting the better MPG.

So on 91 I get 210 miles per tank (5 gallon tank)
On 100 I get 265 miles per tank and 15 more ponies, 15!

Now here's the kicker: 100 octane is $5.99 per gallon. It cost's me $29.95 for a fill up on the 100 and only $13.25 on the 91, but with the 100 octane it's like getting an extra gallon of fuel due to the higher MPG. So it would be more like $16.50 for the 91 as with it I need 6 gallons to go as far as I can with 5 gallons of the 100.

The way I look at it, it costs me roughly $15 to $20 for 15 HP. I have yet to find anything else that you can purchase that will give you the same HP per dollar ratio anywhere and be PERFECTLY SAFE to use everyday all the time.

One can expect the same type of thing from running a higher octane in thier car, just not at the same levels, and it would definetely be a bit more expensive as most VW's have 13 gallon or larger tanks.

As far as I know VW recomends 91 or higher octane in all thier newer engines excluding the 2.0L 8V and the diesels (obviously).

I don't run the 100 in my car as I can't afford it, but I do run 91 as it is a VR6 and anything less can damage the engine according to the sticker VWAG has on on my fuel door. I would still run 91 even if that sticker wasn't there. I have filled it with 100 once, and it ran like a bat out hell. I wish I could afford to run it all the time.

[Skwurlz]

Hey,

I always use the 91 octane gas at least and I think it´s way more expensive here in Germany ( 1,24 Euro a Litre!) cause i chipped it. Some of my friends fill in the 98 or even the 99 octane gas (1,30 a Litre) because they say, they can drive up to 50k´s more with it, but nobody can explain why, so I don´t trust it. Anyway, if you don´t have any problems with the regular gas, go on. But if you´re going to chip it, I would always use, what the tuner told you to fill in! They know, what they are talking ´bout.

Greetz from frosty Germany

Anderson

Fuel is rated quite a bit different in Europe. In my research, 91 in Europe is equivalent to 87 here. The last company I worked for was based in Berlin.

[madness86gti]

soooo.
i should use then 91, just because i have more bolt ons???

[Bimmer Pilot]

Manual reads 89 minimum, recommends Premium (whatever octane that may be). When I commuted, I routinely used 91 and concur with Skwurlz. Driving distance increased between fill-ups.

Now, I am using 89 (Chevron) and 91 (any other brand or for spirited driving) for the detergents and the fact that I primarily drive in town. Pop in a bottle of Lucas every other tank and I'm all good...

[TOYr32]

the higher the octane rating of the fuel, the slower it burns. the slower the burn the farther you can advance your timing. thats where you get the power from, a lean, cool burning fuel/air mixture with lots of time for it to burn. but you need to have software to change the mapping of the engine to maximize the use of higher octane. to just put 91 in a car that is factory programmed to use 87 will do nothing.

Exactly, that's why when you chip your car, or re-program it, it will tell you to use higher octane gas to maximize performance.

[TOYr32]

WHAT IS OCTANE RATING?

Octane, by definition, is the resistance to burn or detonation. The higher the rating, the slower the burn when ignited during the compression burn cycle of the piston. The higher octane allows for better control of burning for high compression engines. So we want to match the correct octane rating of the gasoline to the engine design to ensure complete burning of the gasoline by the engine for maximum fuel economy and clean emissions.

I THOUGHT GASOLINE WITH HIGHER OCTANE REDUCED ENGINE KNOCK?

It did in older engines using carburetors to regulate air/gas mix They cannot as accurately regulate the air/fuel mix going into the engine as a computerized fuel injector. Carburetors need adjustment, as a part of regular maintenance, to keep the air/fuel mix as accurate as possible. So many times, these adjustments were not made regularly causing too much fuel to be mixed with the air. When this happened the gasoline would not burn completely soaking into carbon deposits. This would cause a premature ignition of the gasoline due to the intense heat in the engine cylinder creating "engine knock." When this happened, people would change to the higher octane/slower burning gasoline to resist the premature burn, thus minimizing the knocking problem. And it worked. Good solution.

However, since the middle to late 80’s, engines are designed to use fuel injectors with computers to accurately control the air/fuel mix under all types of temperature and environment concerns. However the accuracy of the fuel injectors and computers is based on using the recommended gasoline for that engine.

Most cars are designed to burn regular unleaded fuels with an octane rating of 87. If the vehicle needs a higher octane rating of 89-93, there is documentation in the owner’s manual, as well as possibly under the fuel gauge and by the fuel fill hole. Usually you will see this rating for high performance engines only.

WHAT IF I PREFER TO USE GASOLINE WITH HIGHER OCTANE RATINGS?

You can, but there are no real benefits, other than the gasoline manufacturers making more money off of you. When you use a fuel with a higher octane rating than your vehicle requires, you can send this unburned fuel into the emissions system. It can also collect in the catalytic converter. When you over stress any system, it can malfunction or not do what it was designed to do properly. In the early 90's, an early warning symptom was a rotten egg smell from the tailpipe. Easy fix, go back to using regular 87 octane gasoline. The rude odor usually disappears after several tanks of gasoline.

DOESN'T HIGHER OCTANE GASOLINE HAVE MORE CLEANING ADDITIVES THAT ARE GOOD FOR MY ENGINE?

No. Government regulations require that all gasoline contain basically the same amount of additives to clean the injectors and valves. The only differences are the type to help create the different octane ratings. All gasoline burns at the same rate, it is the additives that create the different octane ratings for the different types of engines.

I didn't write this. Someone else did, and I'll probably get in trouble for Plagerism (spelling?)

[xXJakeXx]

So it isnt good to run 91 in my 98 mk3 gti 2.0 ey? shit.

[madness86gti]

freaking hey dudes!
iam switching to 89, or whatever my book says for my mighty 1.8t.
is that why there is black residue on my tail pipe?

[TOYr32]

freaking hey dudes!
iam switching to 89, or whatever my book says for my mighty 1.8t.
is that why there is black residue on my tail pipe?

Eh . . . could be . . . I was running 91 for about 3 years in my truck because my chip called for it. Then I found out the other day my chip is defective!!! HAHAHA, I wonder how much damage I've done to my poor little ford engine?

On Average You pay $.20 more for 91. Multiply it by an 18 gallon tank for a total of $3.60. Times filling up once a week. You wasted only $172.80 a year. And most of you don't fill up every week, so that number may vary, along with the price differences. So if you do the math you aren't wasting a whole lot of money. Nothing to Cry about at least.