PRP: Higher octane gas is not better gas!! PANDAMOOO's RESEARCH PROJECT #1!

**PandaMoOo** · 10-10-04, 12:53 PM

Someday someone asked me what octane gas I put in my motorcycle, and I simply said "91" at that moment I realized I had no support for the idea of paying 20 - 30 cents more per gallon except others have told me so! I did a little research on the internet and found not only does higher octane gas provide no power increase, but that it can actually put extra gunk in your engine over time!

What Octane Rating is:
To keep things simple, Octane Rating is the rate at which gasoline reduces compression explosion. See, when your engine squirts a little gas in a cylinder, compresses it, and then it a spark goes off. If your octane rating is too low, the heat generated from the compression may ignite the gas prematurely and cause a "knocking" or "pinging" which is damaging to your engine.

To combat knocking and pinging, gas manufactures have made some gases that don't convert from liquid to vapor form as fast, thus helping car owners not damage their engines.

Higher Octane Gas has more detergents though!:
Yes it does, but thats also because higher octane gas leaves more crap in your engine. With higher octane gases, not all the gas vaporizes before the spark, leaving some carbon atoms in your engine. A lot of gas dealers put EXTRA detergent in higher octane gases so people don't actually damage their engine from paying more. All gasolines have to meet a reasonable federal standard for detergents, you can also pay about $6 and get a carbon cleaner from an auto store to clean your engine.

Exceptions:
The only real exception is if your engine is DESIGNED for high compression. A lot of more expensive cars have more powerful engines that use higher compression to help achieve that power. If they don't get the higher octane gas, they may get "knocking or pinging" which will decrease performance and damage their engine. So... read your manual if you got a high performance vehicle.

For all other cars, they're designed for 87' gas.

In fact, the higher octane gases have been proven to be lower performance because of two factors:
a) Less gas is vaporized before the spark hits.
b) More detergents = less hydrocarbons = less Energy.

So do yourself, and your car a favor, switch over to lower octane gas and stay away from bullshit gasoline companies trying to make you believe octane is related to power, it's not.

If you don't believe me, just search the internet for "higher octane gas" and you'll find hundreds of references I read, or if you don't care about $100 or more a year, I don't care about your money. I'm just trying to help the ignorant learn, because I too once didn't know about this.

(This is the first of a many threads I plan on creating debunking socially excepted norms, I recommend all users at least look for them, and read them and make their own judgements.... It would be cool if other's did the same!)

Sources:
http://www.personal.psu.edu/users/b/j/bjy116/conversion.htm
http://autorepair.about.com/library/weekly/aa060504a.htm
http://www.straightdope.com/columns/041008.html

Mike · 10-10-04, 08:38 PM

The car manual tells me to use 87 gasoline. I stick with 87. Simple as that.

***Admin*** · 10-10-04, 10:58 PM

It is true. Members from the auto forum did their research and comparision analysis of '87 (recommended by auto maker) and '89 and '92 gasoline. The results, the '87 gasoline produced the most HP out of the car compared to the other grades and also '87 was most efficient in terms of gasoline consumption. The auto company knows best when it comes to gasoline grade.

**zoedragon** · 10-11-04, 09:37 AM

It's usually best to go with what your car's manual says. I used to think what PandaMoOo thought back when I owned a little Civic hatchback. I would normally put the 87 gas in, and once it a while when gas prices would drop I would "treat" my car to the more expensive stuff. It wasn't until one day when I was curious as to IF it was better at all. We're trained to believe that more expensive = better, but it isn't necessarily true.

Since upgrading to a little BMW now, the manual says to put in 91 gas, and that's what I do. From what I understand, like others have said, the engine was designed to use that type of gas. Putting in the cheaper stuff would still work and wouldn't leave residue, but the engine would burn it up faster than other engines would. In other words I'd have to refill my tank more often and probably end up spending more on gas in the process than if I were to use the 91 octane.

Are there actually any cars that require the middle octane? I hardly see anyone using that, and Costco gas stations have done away with it altogether. What is it useful for?

Speaking of misleading consumers. There's a Shell station near my house that recently remodeled. It closed for a couple weeks and yanked out all its old gas pumps and everything. When it reopened with all new pumps, I noticed they had also had brand new advertising everywhere for it's "new V-Power" gas. So they had Unleaded (87), Super (89), and V-Power (91). Definitely misleading advertising to anyone who doesn't understand what octane ratings mean! Bottom line I guess is to obey your car manual and not gas station advertising.

ak · 10-25-04, 03:45 PM

Trust the engineer. Stick with what the manual says.

My car was designed for 87 so I use 87. I have MANY times tried 89 and 91 for several tanks and there was no real improvement. IMO, I thought the car accelerated quicker, but how much faster can a Civic feel? heh

***Admin*** · 11-01-04, 10:47 PM

I hear from ordinary consumers that Arco gasoline is not great for our cars and others say the opposite thing (is safe). People say that you get what you pay for and if you continue to use Arco gasoline, your car may be harmed in the long run due to the cheap grade of gasoline.

If you visit a local gas station with no brand name, the price for a gallon is much cheaper than Arco. I tend to stay away from those places. Is there a valid reason to stay away from a no-brand gas station and stick with Mobil, Shell, and Arco only?

**PandaMoOo** · 11-01-04, 11:02 PM

If no one else can provide some information/evidence that will be my next research topic! It is important information, it would require a lot more scientific information... such as case studies and such.

When I got a free moment, I'll look into it. Unless anyone else can offer some statistics or something?

**zoedragon** · 11-02-04, 10:42 AM

I would like to know myself. I have heard an argument from one person saying that the reason Arco is cheaper than the the likes of Chevron, Shell, etc. is because they don't accept credit cards, so they don't have to remove any from their profits for that. They also don't have full service available, which I guess cuts down on costs too? I dunno, I've never used full service because I always figured you had to pay extra for that. Do you?

I had a friend who once told me to stay away from Arco because "they piss in their gas". That made me laugh, but since he wasn't a mechanic I don't know where he got that idea. My most reliable source comes from my brother-in-law who works on cars a lot (he's actually a mechanical engineer though) in his spare time. He says that he and his friend (who IS a mechanic) can always tell when a car regularly uses Arco gas because of all the filthy deposits left behind. I can't remember which part of the engine they were talking about though. He gets his gas mostly from Sam's Club, which is a lot like Costco, right? Their gas tends to be cheaper too, sometimes cheaper than Arco depending on the location.

I have another friend who used to drive an old VW bug. She said whenever her bug started to act sluggish her dad would tell her to put a bottle of Techron into the tank. She said that would clear out the gunk and it would run much better. That leads me to believe that Chevron gas is good for your car, and thus explain why it tends to be one of the most expensive of the lot.

However I don't have any statistics to share, and all this stuff with pricing may just be a marketing ploy to capture a particular audience.

Lone-R · 11-02-04, 11:51 AM

i frequently drive home to the Bay Area and back from Diamond Bar with my 95 Eclipse. I usually use 91 octane, either Chevron or Mobil1. i can get almost 450miles per tank but the last time i made the trip i filled up at one of the cheap gas stations near my home up north. One full tank only lasted me about 360 miles.

**PandaMoOo** · 11-02-04, 12:21 PM

Aye... from what research I remember, detergents are an important additive to gasoline. They help clean the left over raw carbons (gunk) from your engine. There is a state minimum, which is relatively good, but many companies claim to go above and behind.

I'm sure it varies from time to time, and cars are fickle things anyway. I'll do some research after my Mechanical Engineering Dynamics Mid term on wednesday.

ak · 11-02-04, 04:58 PM

I guess the greatest difference might come with the matter of carbon deposit build up. Cheaper gasoline leaves a greater amount of carbon deposits (which I simply know is bad for the engine), while more expensive gasoline (that usually have added detergent additives) not only leave less deposits, but clean the engine.

As for me, I will only put (1) Shell (2) Chevron (3) 76 because they are the best refined gasolines that I can find around here. I'd rather pay $0.50-$1.50 more per tank and use good gasoline and not build as much carbon build up, than to be thrifty and have my car broken down 20,000 miles earlier because I was cheap.

To each his own, if one wishes to remain ignorant... any gasoline "will do".

**zoedragon** · 11-02-04, 05:03 PM

Which is why I would never EVER buy a car from a rental company. Ugh I can't imagine the wear and tear renters put onto the the cars, not to mention putting in the cheapest gas possible no matter what kind of car it is.

Anyway, anyone know the quality of Costco gas?

i2ealphaze · 11-02-04, 07:12 PM

im glad someone did research on this stuff, otherwise i'd be paying 2.55+(9/10ths of a cent) for some gas that I would not really need in the first place.

***Admin*** · 11-02-04, 10:30 PM

Quote:

Originally Posted by Lone-R

i frequently drive home to the Bay Area and back from Diamond Bar with my 95 Eclipse. I usually use 91 octane, either Chevron or Mobil1. i can get almost 450miles per tank but the last time i made the trip i filled up at one of the cheap gas stations near my home up north. One full tank only lasted me about 360 miles.

I've heard this case several times from regular drivers.

Quote:

Originally Posted by ak

As for me, I will only put (1) Shell (2) Chevron (3) 76 because they are the best refined gasolines that I can find around here.

Is that the order in terms of gasoline quality?

Quote:

Originally Posted by zoedragon

Which is why I would never EVER buy a car from a rental company. Ugh I can't imagine the wear and tear renters put onto the the cars, not to mention putting in the cheapest gas possible no matter what kind of car it is.

Don't forget lease vehicles (although the dealers transform the car back to great condition after the inspections). My brother took his fairly new Nissan Pathfinder (previous generation model that was closed to ending his lease) to a desert nearby Vegas and we had a blast. Good thing the SUV was made to do off-roading.

Quote:

Originally Posted by i2ealphaze

im glad someone did research on this stuff, otherwise i'd be paying 2.55+(9/10ths of a cent) for some gas that I would not really need in the first place.

Be sure to inform your friends and families. Stick with the gasoline grade recommended by the manufacturer at all times.

**zoedragon** · 11-03-04, 02:17 PM

Quote:

Originally Posted by KayCee

Don't forget lease vehicles (although the dealers transform the car back to great condition after the inspections). My brother took his fairly new Nissan Pathfinder (previous generation model that was closed to ending his lease) to a desert nearby Vegas and we had a blast. Good thing the SUV was made to do off-roading.

From what I understand of lease vehicles, the dealer will charge you for any and all damage sustained to the vehicle. When you lease a car, it still belongs to the dealer and they want it back in as good a condition as when it left. Dealers advise leasers to always take the car for an inspection before turning your car in after its lease. The dealer will likely charge you more to repair it than if you were to get it repaired on your own. I don't know if this also refers to the condition of the engine though.

ak · 11-03-04, 04:07 PM

Quote:

Originally Posted by KayCee

Is that the order in terms of gasoline quality?

Yes. I did a personal research long time ago and tests showed that Shell > Chevron > 76.

There were other companies that scored "better", but they are not in CA.

**zoedragon** · 11-03-04, 04:40 PM

I would have thought Chevron was better than Shell, but only because of the price. Every workday I pass by a major intersection where 4 gas stations battle it out: Shell, Chevron, Arco and Mobil. The Mobil was sometimes cheaper than Arco, but it closed and became a no-name gas station. And now that one closed too, leaving a stupid empty lot.

Anyway, the order of pricing is always Chevron > Shell > Arco. Do these places all get their gas from a consistent source? I had heard that Texaco gets gas from different sources, so their quality tends to vary.

BTW what are the better ones that are out of state? It's good to keep them in mind in case I do some traveling.

***Admin*** · 11-03-04, 05:04 PM

Quote:

Originally Posted by zoedragon

BTW what are the better ones that are out of state? It's good to keep them in mind in case I do some traveling.

Good idea.
I put Mobil gasoline 95% of the times. Do you think my engine would have more gunks now (from Mobil gasoline) compared to using Shell gasoline?

some2 · 11-22-04, 11:18 AM

Newer engines have knock sensors which may detect pinging and thus retard the timing until the knock/pinging is gone. The timing adjustment will cause the knock to go away, but with it will go performance and efficiency. Thus, 87 octane may "work" in your car, but it could result in a much less efficient combustion. If you're not sure, record your mileage for two full tanks of 87, 89, then 91. If you car says 89/91 only, don't use anything less or you're looking for trouble.

Also, if fuel injected, occasionally run a fuel injector cleaner (fuel add-in) every couple tanks and you should increase your fuel efficiency at least slightly. They're usually around $3.00 or so from an auto parts store, and are just put into your tank before you fill. They will help to clean up carbon deposits from your fuel injectors, which can help majorly.

For those with older cars, you can also potentially gain a bit of performance/fuel efficiency by running products like 'Marvel Mystery Oil' in your oil every once in a while (15000+ miles), which will clean out sludge and other deposits in your engine.

10-10-04, 12:53 PM	#1 (permalink)
PandaMoOo GCP.com Admin Joined: Aug 2004 Location: Mission Viejo, CA Posts: 401	PRP: Higher octane gas is not better gas!! PANDAMOOO's RESEARCH PROJECT #1! Someday someone asked me what octane gas I put in my motorcycle, and I simply said "91" at that moment I realized I had no support for the idea of paying 20 - 30 cents more per gallon except others have told me so! I did a little research on the internet and found not only does higher octane gas provide no power increase, but that it can actually put extra gunk in your engine over time! What Octane Rating is: To keep things simple, Octane Rating is the rate at which gasoline reduces compression explosion. See, when your engine squirts a little gas in a cylinder, compresses it, and then it a spark goes off. If your octane rating is too low, the heat generated from the compression may ignite the gas prematurely and cause a "knocking" or "pinging" which is damaging to your engine. To combat knocking and pinging, gas manufactures have made some gases that don't convert from liquid to vapor form as fast, thus helping car owners not damage their engines. Higher Octane Gas has more detergents though!: Yes it does, but thats also because higher octane gas leaves more crap in your engine. With higher octane gases, not all the gas vaporizes before the spark, leaving some carbon atoms in your engine. A lot of gas dealers put EXTRA detergent in higher octane gases so people don't actually damage their engine from paying more. All gasolines have to meet a reasonable federal standard for detergents, you can also pay about $6 and get a carbon cleaner from an auto store to clean your engine. Exceptions: The only real exception is if your engine is DESIGNED for high compression. A lot of more expensive cars have more powerful engines that use higher compression to help achieve that power. If they don't get the higher octane gas, they may get "knocking or pinging" which will decrease performance and damage their engine. So... read your manual if you got a high performance vehicle. For all other cars, they're designed for 87' gas. In fact, the higher octane gases have been proven to be lower performance because of two factors: a) Less gas is vaporized before the spark hits. b) More detergents = less hydrocarbons = less Energy. So do yourself, and your car a favor, switch over to lower octane gas and stay away from bullshit gasoline companies trying to make you believe octane is related to power, it's not. If you don't believe me, just search the internet for "higher octane gas" and you'll find hundreds of references I read, or if you don't care about $100 or more a year, I don't care about your money. I'm just trying to help the ignorant learn, because I too once didn't know about this. (This is the first of a many threads I plan on creating debunking socially excepted norms, I recommend all users at least look for them, and read them and make their own judgements.... It would be cool if other's did the same!) Sources: http://www.personal.psu.edu/users/b/j/bjy116/conversion.htm http://autorepair.about.com/library/weekly/aa060504a.htm http://www.straightdope.com/columns/041008.html __________________ -PandaMoOo- www.GradeCalPoly.com

10-10-04, 10:58 PM	#3 (permalink)
*Admin* Think About It Joined: Sep 2003 Location: Los Angeles, CA Posts: 4,946	It is true. Members from the auto forum did their research and comparision analysis of '87 (recommended by auto maker) and '89 and '92 gasoline. The results, the '87 gasoline produced the most HP out of the car compared to the other grades and also '87 was most efficient in terms of gasoline consumption. The auto company knows best when it comes to gasoline grade. __________________ Cal Poly Forums

10-25-04, 03:45 PM	#5 (permalink)
ak Cal Poly Guru Joined: Oct 2003 Location: LA Posts: 605	Trust the engineer. Stick with what the manual says. My car was designed for 87 so I use 87. I have MANY times tried 89 and 91 for several tanks and there was no real improvement. IMO, I thought the car accelerated quicker, but how much faster can a Civic feel? heh __________________ If you think education is expensive, try ignorance. Education is the progressive discovery of our own ignorance.

11-01-04, 10:47 PM	#6 (permalink)
*Admin* Think About It Joined: Sep 2003 Location: Los Angeles, CA Posts: 4,946	I hear from ordinary consumers that Arco gasoline is not great for our cars and others say the opposite thing (is safe). People say that you get what you pay for and if you continue to use Arco gasoline, your car may be harmed in the long run due to the cheap grade of gasoline. If you visit a local gas station with no brand name, the price for a gallon is much cheaper than Arco. I tend to stay away from those places. Is there a valid reason to stay away from a no-brand gas station and stick with Mobil, Shell, and Arco only? __________________ Cal Poly Forums

11-01-04, 11:02 PM	#7 (permalink)
PandaMoOo GCP.com Admin Joined: Aug 2004 Location: Mission Viejo, CA Posts: 401	If no one else can provide some information/evidence that will be my next research topic! It is important information, it would require a lot more scientific information... such as case studies and such. When I got a free moment, I'll look into it. Unless anyone else can offer some statistics or something? __________________ -PandaMoOo- www.GradeCalPoly.com

10-10-04, 08:38 PM	#2 (permalink)
Mike Enthusiast Joined: Jan 2004 Location: Fullerton Posts: 199	The car manual tells me to use 87 gasoline. I stick with 87. Simple as that.

10-11-04, 09:37 AM	#4 (permalink)
zoedragon Fire-breather Joined: Mar 2004 Location: Inglewood, CA Posts: 668	It's usually best to go with what your car's manual says. I used to think what PandaMoOo thought back when I owned a little Civic hatchback. I would normally put the 87 gas in, and once it a while when gas prices would drop I would "treat" my car to the more expensive stuff. It wasn't until one day when I was curious as to IF it was better at all. We're trained to believe that more expensive = better, but it isn't necessarily true. Since upgrading to a little BMW now, the manual says to put in 91 gas, and that's what I do. From what I understand, like others have said, the engine was designed to use that type of gas. Putting in the cheaper stuff would still work and wouldn't leave residue, but the engine would burn it up faster than other engines would. In other words I'd have to refill my tank more often and probably end up spending more on gas in the process than if I were to use the 91 octane. Are there actually any cars that require the middle octane? I hardly see anyone using that, and Costco gas stations have done away with it altogether. What is it useful for? Speaking of misleading consumers. There's a Shell station near my house that recently remodeled. It closed for a couple weeks and yanked out all its old gas pumps and everything. When it reopened with all new pumps, I noticed they had also had brand new advertising everywhere for it's "new V-Power" gas. So they had Unleaded (87), Super (89), and V-Power (91). Definitely misleading advertising to anyone who doesn't understand what octane ratings mean! Bottom line I guess is to obey your car manual and not gas station advertising.

11-02-04, 10:42 AM	#8 (permalink)
zoedragon Fire-breather Joined: Mar 2004 Location: Inglewood, CA Posts: 668	I would like to know myself. I have heard an argument from one person saying that the reason Arco is cheaper than the the likes of Chevron, Shell, etc. is because they don't accept credit cards, so they don't have to remove any from their profits for that. They also don't have full service available, which I guess cuts down on costs too? I dunno, I've never used full service because I always figured you had to pay extra for that. Do you? I had a friend who once told me to stay away from Arco because "they piss in their gas". That made me laugh, but since he wasn't a mechanic I don't know where he got that idea. My most reliable source comes from my brother-in-law who works on cars a lot (he's actually a mechanical engineer though) in his spare time. He says that he and his friend (who IS a mechanic) can always tell when a car regularly uses Arco gas because of all the filthy deposits left behind. I can't remember which part of the engine they were talking about though. He gets his gas mostly from Sam's Club, which is a lot like Costco, right? Their gas tends to be cheaper too, sometimes cheaper than Arco depending on the location. I have another friend who used to drive an old VW bug. She said whenever her bug started to act sluggish her dad would tell her to put a bottle of Techron into the tank. She said that would clear out the gunk and it would run much better. That leads me to believe that Chevron gas is good for your car, and thus explain why it tends to be one of the most expensive of the lot. However I don't have any statistics to share, and all this stuff with pricing may just be a marketing ploy to capture a particular audience.

11-02-04, 11:51 AM	#9 (permalink)
Lone-R Newcomer Joined: Apr 2004 Location: 707/909 Posts: 25	i frequently drive home to the Bay Area and back from Diamond Bar with my 95 Eclipse. I usually use 91 octane, either Chevron or Mobil1. i can get almost 450miles per tank but the last time i made the trip i filled up at one of the cheap gas stations near my home up north. One full tank only lasted me about 360 miles. __________________ Ryan

11-02-04, 12:21 PM	#10 (permalink)
PandaMoOo GCP.com Admin Joined: Aug 2004 Location: Mission Viejo, CA Posts: 401	Aye... from what research I remember, detergents are an important additive to gasoline. They help clean the left over raw carbons (gunk) from your engine. There is a state minimum, which is relatively good, but many companies claim to go above and behind. I'm sure it varies from time to time, and cars are fickle things anyway. I'll do some research after my Mechanical Engineering Dynamics Mid term on wednesday. __________________ -PandaMoOo- www.GradeCalPoly.com

11-02-04, 04:58 PM	#11 (permalink)
ak Cal Poly Guru Joined: Oct 2003 Location: LA Posts: 605	I guess the greatest difference might come with the matter of carbon deposit build up. Cheaper gasoline leaves a greater amount of carbon deposits (which I simply know is bad for the engine), while more expensive gasoline (that usually have added detergent additives) not only leave less deposits, but clean the engine. As for me, I will only put (1) Shell (2) Chevron (3) 76 because they are the best refined gasolines that I can find around here. I'd rather pay $0.50-$1.50 more per tank and use good gasoline and not build as much carbon build up, than to be thrifty and have my car broken down 20,000 miles earlier because I was cheap. To each his own, if one wishes to remain ignorant... any gasoline "will do". __________________ If you think education is expensive, try ignorance. Education is the progressive discovery of our own ignorance.

11-02-04, 05:03 PM	#12 (permalink)
zoedragon Fire-breather Joined: Mar 2004 Location: Inglewood, CA Posts: 668	Which is why I would never EVER buy a car from a rental company. Ugh I can't imagine the wear and tear renters put onto the the cars, not to mention putting in the cheapest gas possible no matter what kind of car it is. Anyway, anyone know the quality of Costco gas?

11-02-04, 07:12 PM	#13 (permalink)
i2ealphaze Newcomer Joined: Nov 2004 Posts: 43	im glad someone did research on this stuff, otherwise i'd be paying 2.55+(9/10ths of a cent) for some gas that I would not really need in the first place.

11-03-04, 04:40 PM	#17 (permalink)
zoedragon Fire-breather Joined: Mar 2004 Location: Inglewood, CA Posts: 668	I would have thought Chevron was better than Shell, but only because of the price. Every workday I pass by a major intersection where 4 gas stations battle it out: Shell, Chevron, Arco and Mobil. The Mobil was sometimes cheaper than Arco, but it closed and became a no-name gas station. And now that one closed too, leaving a stupid empty lot. Anyway, the order of pricing is always Chevron > Shell > Arco. Do these places all get their gas from a consistent source? I had heard that Texaco gets gas from different sources, so their quality tends to vary. BTW what are the better ones that are out of state? It's good to keep them in mind in case I do some traveling.

11-22-04, 11:18 AM	#19 (permalink)
some2 Newcomer Joined: Nov 2004 Posts: 17	Newer engines have knock sensors which may detect pinging and thus retard the timing until the knock/pinging is gone. The timing adjustment will cause the knock to go away, but with it will go performance and efficiency. Thus, 87 octane may "work" in your car, but it could result in a much less efficient combustion. If you're not sure, record your mileage for two full tanks of 87, 89, then 91. If you car says 89/91 only, don't use anything less or you're looking for trouble. Also, if fuel injected, occasionally run a fuel injector cleaner (fuel add-in) every couple tanks and you should increase your fuel efficiency at least slightly. They're usually around $3.00 or so from an auto parts store, and are just put into your tank before you fill. They will help to clean up carbon deposits from your fuel injectors, which can help majorly. For those with older cars, you can also potentially gain a bit of performance/fuel efficiency by running products like 'Marvel Mystery Oil' in your oil every once in a while (15000+ miles), which will clean out sludge and other deposits in your engine.

11-22-04, 11:22 AM	#20 (permalink)
zoedragon Fire-breather Joined: Mar 2004 Location: Inglewood, CA Posts: 668