Start switching to 87 octane gas.
- Thread starter linhsy
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Iowa4Runner
New member
Kmvreter said:
I bought an OBDII scanner ($96 complete kit) from http://obddiagnostics.com/order.html
It's obvious that the device is homemade, but it's decently built and seems to work pretty well. The software is a free download and works on modern Windows operating systems. I used it with a laptop running Windows XP. I drove around as the laptop recorded throttle position, ignition timing, and RPM. Later I imported the data file into Excel and made some graphs.
Iowa4Runner
New member
Iowa4Runner said:
One thing I forgot to mention is that my 4Runner is a 2004. The 2005's might have changed to a different protocol, so make sure you verify compatibility if you plan to use a scanner with a 2005 model 4Runner.
greasefingers
New member
Iowa4Runner said:
Yea I recently looked at the BR-3 from that site. I also started a new thread on this, in the General Discussions Section, as to not hyjack.. The 2005 do indeed use the newer CAN protocol.
At the risk of igniting a firestorm....
I am not professionally certified in gasoline analysis, but I am a scholar whose job it is to carefully analyse words and meaning. I read the "top tier" web site stuff. I wanted it to be true so I could feel good about something else I knew that most other people didn't.... I wished it were true so that all my questions about gasoline purchasing would be answered in black and white. But...neither wanting nor wishing makes the article true. First off, I want scientific analysis, not some marketing lingo. Second, there are wayyyyyy too many unanswered questions that the website avoids or steps around--it actually struck me that a politician may have written it in how carefully it phrases things to sound one way but not necessarily mean that in any way they can be held liable for! For just one example: note that it doesn't dare claim that any of the four mentioned big auto makers agree on any standard, and certainly it doesn't dare claim they are behind this particular standard, but it is phrased so as to make the casual reader think that the big guys are supporting this web site info. So....I would exercise some caution in jumping on the bandwagon about "top tier" fuel until we get some evidence that the web site marketers have some science in their corner. Just a thought....
I am not professionally certified in gasoline analysis, but I am a scholar whose job it is to carefully analyse words and meaning. I read the "top tier" web site stuff. I wanted it to be true so I could feel good about something else I knew that most other people didn't.... I wished it were true so that all my questions about gasoline purchasing would be answered in black and white. But...neither wanting nor wishing makes the article true. First off, I want scientific analysis, not some marketing lingo. Second, there are wayyyyyy too many unanswered questions that the website avoids or steps around--it actually struck me that a politician may have written it in how carefully it phrases things to sound one way but not necessarily mean that in any way they can be held liable for! For just one example: note that it doesn't dare claim that any of the four mentioned big auto makers agree on any standard, and certainly it doesn't dare claim they are behind this particular standard, but it is phrased so as to make the casual reader think that the big guys are supporting this web site info. So....I would exercise some caution in jumping on the bandwagon about "top tier" fuel until we get some evidence that the web site marketers have some science in their corner. Just a thought....
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cmj685 said:
You wait I'm using the Top Tier gas. It's a standard that these companies stated they would meet and they are testing the gas to confirm it meets the standard. Plus Toyota, BMW etc let them use their names and the oil companies are letting them use their names so that is good enough for me, unless you have evidence that would help all of us make a better gas decision, I'm going with the Top Tier, which is also the cheapest gas in my area.
Northof49
New member
I just buy gas from one of the big TT brands...it's usually the most accessible and the prices are close enough for me not to care.
Maybe the cheap stuff is fine, or maybe it's not the best. If anyone's worried about, there's a very simple solution....just buy the TT stuff and be done with it.
I think we're making this more complicated than it needs to be.....
Maybe the cheap stuff is fine, or maybe it's not the best. If anyone's worried about, there's a very simple solution....just buy the TT stuff and be done with it.
I think we're making this more complicated than it needs to be.....
Looks like gas is becoming the new oil debate. So gas and oil is all the same and just buy a good brand and follow the manufactures recommendations for maintaining your 4runner and the world will be a wonderful place. You know with "car nuts" like us I doubt that will ever be true. 
Re: way to get gas cheaper
Lots of credit card companies are doing this, now...
I have a Citibank "Dividend" card that gives you 5% back on fuel purchases (as well as grocery store purchases), as well as a Discover Gasoline Card that gives me 5% back on the first $1500 of fuel purchases each year. Lots of ways to get money back for the things you have to buy anyways to survive.
Ricky
Lots of credit card companies are doing this, now...
I have a Citibank "Dividend" card that gives you 5% back on fuel purchases (as well as grocery store purchases), as well as a Discover Gasoline Card that gives me 5% back on the first $1500 of fuel purchases each year. Lots of ways to get money back for the things you have to buy anyways to survive.
Ricky
h7009 said:
Boaz said:
On my last road trip where I was going through a lot of mountains through Idaho, Utah, Colorado, New Mexico, etc, a lot of gas station's "regular" unleaded was actually 85 octane. I still pumped this into my 4Runner and had no problems whatsoever.
Some of the places I stopped were no-name stations in the middle of nowhere.
Ricky
Pistonslap
New member
The simple rule is this: If it runs fine on 87 octane (or lower), then that is what you should run.
Let
Let
Mr.yoshimura
New member
"Top Tier" gas at non TT gas station humm:rolleye2: I know for a FACT that the same gas that get deliver to exxon get deliver to superamerican gas station too!
You're somewhat right and somewhat wrong.
Newer cars with higher compression ratios will run more agressive timing if provided with premium gasoline, and as such will get better fuel economy and generate more power with higher octane fuels. In the same regard, when I pumped 85 octane fuel into my 4Runner, it pulled back some timing to prevent preignition (detonation) under load. The knock sensor takes care of this for you, and seems to work better on the 4Runner than most newer cars I've seen. The drawback of this was every large uphill grade I came to, I was having to drop it into 4th gear just to maintain speed. It also didn't help that I was at high elevations through a lot of this driving (6000-8000ft above sea level), so that took away some power as well.
I had a '98 Acura Integra GS-R that I bought brand new back in January 1998. That car had a high compression ratio and required premium fuel. Depending on where I purchased my fuel, my fuel mileage would fluctuate slightly. If I always filled up at the same station, I always got the same gas mileage no matter what. I did a 99% highway driving at the time and although I did drive quite quickly, my mileage was always the same if I gassed up at the same station. Texaco, Shell, and Race Trak netted me some of the worst gas mileage. Exxon, Diamond Shamrock, and Chevron netted me slightly better economy. I always tried to fill up at Exxon and Diamond Shamrock whenever possible with that car and it ran great over the course of the 53k miles I owned it. Back then, and still today, I keep detailed records of all of my vehicle 'events' including writing down every fillup the total miles on the vehicle, miles traveled, gallons pumped, price paid, etc. It makes it easy for me to track my mileage that way.
Ricky
Newer cars with higher compression ratios will run more agressive timing if provided with premium gasoline, and as such will get better fuel economy and generate more power with higher octane fuels. In the same regard, when I pumped 85 octane fuel into my 4Runner, it pulled back some timing to prevent preignition (detonation) under load. The knock sensor takes care of this for you, and seems to work better on the 4Runner than most newer cars I've seen. The drawback of this was every large uphill grade I came to, I was having to drop it into 4th gear just to maintain speed. It also didn't help that I was at high elevations through a lot of this driving (6000-8000ft above sea level), so that took away some power as well.
I had a '98 Acura Integra GS-R that I bought brand new back in January 1998. That car had a high compression ratio and required premium fuel. Depending on where I purchased my fuel, my fuel mileage would fluctuate slightly. If I always filled up at the same station, I always got the same gas mileage no matter what. I did a 99% highway driving at the time and although I did drive quite quickly, my mileage was always the same if I gassed up at the same station. Texaco, Shell, and Race Trak netted me some of the worst gas mileage. Exxon, Diamond Shamrock, and Chevron netted me slightly better economy. I always tried to fill up at Exxon and Diamond Shamrock whenever possible with that car and it ran great over the course of the 53k miles I owned it. Back then, and still today, I keep detailed records of all of my vehicle 'events' including writing down every fillup the total miles on the vehicle, miles traveled, gallons pumped, price paid, etc. It makes it easy for me to track my mileage that way.
Ricky
Pistonslap said:
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The main thing I try to do is just vary where I buy my gas from - I try not to fill up with the same brand time after time (somebody suggested sticking with the same brand can create a build up of additives - not sure whether that is true but it costs me nothing to vary where I buy from anyway). As suggested here, I avoid anywhere that looks old and likely to have tanks which may be contaminated. I stick with 87 nearly all of the time - I get a small increase in economy with higher octanes but not enough to justify the increase price. That said, the price difference between 87 and 91 seems to be sticking at about 10c even as the prices rise so the premium for 91 seems less as a percentage than it used to be.
Pistonslap
New member
RickyCRX said:
Your somewhat missing some information.
Compression is not increased to advance timing. While timing may have to be retarded to prevent preignition, advancing the timing does not yield increased performance.
Using your thinking can you explain why in the mountains you see lower octane fuels? You don't see 85 octane at sea level, and mid grade at sea level isn't 87 octane either. The thinner air makes less compression requiring a more volatile fuel.
It is great that you are keeping detailed records of miles driven, gallons, price, but I would be willing to bet you are missing some critical data and that is environmental data such as ambient air temperature and relative humidity. You see, it is a mixture and you like most people only keep records on the part you pay for. Air density is as important as the amount of fuel going in. Cars are not built to run at high altitudes so of course your not going to get the same performance in the thin air at 8000 feet as your would on a humid day in Fla.
It is easy to tell when your octane level is too low. The hard part that people understanding is that it can be just as bad if it is too high.
I never said compression was increased to advance timing.
Irregardless; I have seen the negative effects of low octane fuel in vehicles that are designed to run on it. Poor fuel economy (to the point that the economy difference DOES exceed the additional cost to run premium) and lack of power are the two biggest problems.
Have you ever tried driving a car that is DESIGNED for premium on regular fuel? It runs like crap, bottom line.
In the case of my CRXs, where I have installed turbochargers on two of them, I am artificially increasing the compression ratio with forced induction, thereby necessitating premium fuel. I would never think of running regular or even midgrade on either of those cars.
Trust me, I know a lot more about this stuff than you would think, I just tried to keep things generalized in my previous post. When you live and commute in one city and the atmospheric situations where you operate your vehicle are pretty close for months at a time, it's not hard to develop close trends on what stations give you different results; especially when a tank of gas would only last you 2-3 days at MOST in a car that gets 30+mpg (I did a LOT of driving at the time).
Irregardless; I have seen the negative effects of low octane fuel in vehicles that are designed to run on it. Poor fuel economy (to the point that the economy difference DOES exceed the additional cost to run premium) and lack of power are the two biggest problems.
Have you ever tried driving a car that is DESIGNED for premium on regular fuel? It runs like crap, bottom line.
In the case of my CRXs, where I have installed turbochargers on two of them, I am artificially increasing the compression ratio with forced induction, thereby necessitating premium fuel. I would never think of running regular or even midgrade on either of those cars.
Trust me, I know a lot more about this stuff than you would think, I just tried to keep things generalized in my previous post. When you live and commute in one city and the atmospheric situations where you operate your vehicle are pretty close for months at a time, it's not hard to develop close trends on what stations give you different results; especially when a tank of gas would only last you 2-3 days at MOST in a car that gets 30+mpg (I did a LOT of driving at the time).
Pistonslap said:
Pistonslap
New member
RickyCRX said:
As I have said, if you increase the compression, you must increase the octane. Any car designed to run on higher octane fuel needs it and you shouldn't run anything lower unless you are at a high altitude. I think we agree on that.
Now on a car that is designed to run on 87 octane, how could you possibly see any gains by increasing the octane rating? A gallon of 87 octane has the same stored energy that a gallon of 1000 octane does (Hypothetically speaking of course.) Where are you going to gain power?
Let me add this direct quote from the Chevron website:
Using gasoline with an antiknock rating higher than that required to prevent knock or to prevent spark retardation by the knock sensor will not improve a vehicle's performance.
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