schneidermj
New member
Sams 91 for me.
What fuel do you run?
- Thread starter MacVay
- Start date
24runners
New member
Dansnare said:
You probably wont notice...unless you can tell that its not as "responsive" as it usually is...The ecu pulls timing and the engine runs fine...there is no damage...it will run fine on 87 whether the ecu has to pull timing or not. It might not have to pull timing at all with 87...might be running the same timing as it would with 93
Thats why I will do my little test. I choose to use 93 "just in case"...I want all the timing advance I can get...but there is no harm in driving with retarded timing, thats what the ecu adjustment is for 
I have obdII software and a laptop that I can use to monitor the timing advance/retard and knock.
But unless you have noticeable stumbling or severe power loss, you arent having any issues with 87 octane.
Last edited:
Hitman
New member
24runners said:
No, but you said this:
...I choose to use 93 "just in case"...I want all the timing advance I can get....
You won't get any advance by running high octane fuel. You'll just be less likely to get retarded timing because of the higher octane fuel that you're using. With the timing at the factory set point, you are not getting timing advance.
....I am comparing the timing using 87 and using 93...simply saying that with cheap gas, you have more of a chance that your ecu is pulling timing.....maybe it is...maybe it isnt...I havent monitored knock in this 4Runner yet....I'll spend the extra $2 and know I'm doing the best I can to help the ecu keep my timing where it is
There is a reason toyota recommends 91 or higher octane....and I'll be willing to bet it is because of the timing and performance issue. Am I the only one with that in my owner's manual???
I will use my laptop to monitor my timing advance and retard....the next tank of gas I will only put in about a quarter tank of 87..let it run for about 40/50 miles on that...then monitor the timing and knock....we'll see if the timiing is affected by the cheaper gas
I have an OBDII scan tool that will display and record live data stream. I have already tested my 4Runner with 87 octane gas and it did not detect knock nor retard timing at all, so I'm satisfied that 87 octane fuel will work perfectly fine for me. As my 4Runner ages, it might require higher octane fuel to avoid knock, but this is normal for every vehicle as it ages, due to combustion chamber deposits, which can raise the compression ratio and in turn, cause knock to occur on 87 octane fuel.
ToolmanJohn
New member
Re: Re: Re: Re: Pre-Detonation Resistance
It RESISTS predetonation, it does not burn hotter. It HELPS prevent compressed fuel from exploding in the cyclinder before it's supposed to. This usually only will apply to a higher compression motor. If the motor runs fine with a lower octane fuel (87) then burning a higher octane fuel is pointless.
An exception could be HEAVY LOAD, such as towing a large weight. The engine works harder, gets hotter. A hot engine (above what would be considered "normal") would be more likely to ping and knock.
24runners said:
It RESISTS predetonation, it does not burn hotter. It HELPS prevent compressed fuel from exploding in the cyclinder before it's supposed to. This usually only will apply to a higher compression motor. If the motor runs fine with a lower octane fuel (87) then burning a higher octane fuel is pointless.
An exception could be HEAVY LOAD, such as towing a large weight. The engine works harder, gets hotter. A hot engine (above what would be considered "normal") would be more likely to ping and knock.
24runners
New member
I stand corrected if the lower octane doesnt burn any hotter than higher...maybe I was getting that confused with 87 burning longer or quicker than 93...who knows
"You won't get any advance by running high octane fuel. You'll just be less likely to get retarded timing because of the higher octane fuel that you're using."
THAT IS WHAT I MEANT BY SAYING "I want all the timing advance I can get"
I appologize if that wasnt clear. But that is EXACTLY my point. I WILL BE LESS LIKELY TO GET RETARDED TIMING BECAUSE OF THE HIGHER OCTANE FUEL THAT I'M USING.
Maybe we are aguing the same thing, but I'm not saying it clearly enough. I'm not saying I will get infinite timing advance...as my previous post stated...
"It might not have to pull timing at all with 87...might be running the same timing as it would with 93"
I understand that it is entirely possible that the timing is exactly the same on 87 as it is on 93...but JUST LIKE YOU SAID..."You'll just be less likely to get retarded timing because of the higher octane fuel that you're using." and that is my whole arguement on why I use 93 for that "less likely to pull timing" benifit, so I assume that we are in agreement?? correct???
Again, I apologize if I am being unclear with what post.
"You won't get any advance by running high octane fuel. You'll just be less likely to get retarded timing because of the higher octane fuel that you're using."
THAT IS WHAT I MEANT BY SAYING "I want all the timing advance I can get"
I appologize if that wasnt clear. But that is EXACTLY my point. I WILL BE LESS LIKELY TO GET RETARDED TIMING BECAUSE OF THE HIGHER OCTANE FUEL THAT I'M USING.
Maybe we are aguing the same thing, but I'm not saying it clearly enough. I'm not saying I will get infinite timing advance...as my previous post stated...
"It might not have to pull timing at all with 87...might be running the same timing as it would with 93"
I understand that it is entirely possible that the timing is exactly the same on 87 as it is on 93...but JUST LIKE YOU SAID..."You'll just be less likely to get retarded timing because of the higher octane fuel that you're using." and that is my whole arguement on why I use 93 for that "less likely to pull timing" benifit, so I assume that we are in agreement?? correct???
Again, I apologize if I am being unclear with what post.
digital0ne
New member
Shell PLUS 89 (Free ski passes every fill up )
Plus I use a fuel addative. MASSIVE difference when I use vs when I don't. It's called Freedom Fuel Addative. You need a membership to get it though, anyone interested, pm me.
Boost's pick up and increases fuel mileage, just add it in when I fill up.
I am sad to see no one in the 100+ isle though...
Apparently no one's 4Runner is set up to run jet fuel....
yet.....
)Plus I use a fuel addative. MASSIVE difference when I use vs when I don't. It's called Freedom Fuel Addative. You need a membership to get it though, anyone interested, pm me.
Boost's pick up and increases fuel mileage, just add it in when I fill up.
I am sad to see no one in the 100+ isle though...
Apparently no one's 4Runner is set up to run jet fuel....
yet.....
Fro-Runner
New member
I have another point for all of you 4Runner Guru's to ponder. The altitude where one drives his/her vehicle has an effect on what octane rating should be used.....correct? The oxygen level is higher at an altitude closer to sea level and lowers as the elevation rises. People who live in the higher elevations can run fuel octane as low as 85 while in the deep south (New Orleans--sits 5 ft. below sea level), driver's gasolines are formulated with higher octane ratings....ie 89-91-93! Also, doesn't humidity play a small fraction in how fuel behaves within the combustion sequence? I live and drive mostly at the 1,100 ft level here in southern California, therefore I only use Chervon mid-grade 89 octane gasoline (we have octane ratings of 87-89-91). If I was to move back to the New Orleans/Houston areas I would NOT use anything less than 91 octane in my 4Runner. I figure by using an octane of 87 and especially 85 would cause it to KNOCK the aluminum valve covers off my VVT-i V6 Japanese powerplant. Please feel free to enlighten me if I am half correct, totally incorrect, somewhat correct, or just correct.
BTW, my back aches a little. The runner seats are a tide bit too firm or my body's backside is not padded enough.
BTW, my back aches a little. The runner seats are a tide bit too firm or my body's backside is not padded enough.
I would love to be able to put the 4R on the dyno on 87 and then on 91 and see the results.
I would love to just put 87 in my 05 V8 but I can't do it. I have a problem!
They way I see it is this. I can put in 97 all of the time and if I find detonation move higher up the line.
or
Put in 91 and never have to worry about it. For me, it is 91 and no looking back.
Again,
It would be interesting to have some dyno results. (I'm pretty sure they would show under most circumstances that there is no power difference.)
I wonder though if you took random samples from 87 regular gas to see what the absolute octane rating is as there are many factors that could affect this outcome. Again, why I feel better buying 91.
Interesting though, I used to own a Honda Accord V6 Coupe and it had no knock sensor (87 in the owners manual) but I ran 91 on it all the time. Then later I read an article in Car and Driver where they tested several cars on different octane ratings and one of them was an Accord V6 and they found it was slower on 91 than it was on 87. Again, no knock sensor. There were several other cars though and I can't remember the outcome of the rest.
Anybody else read this article?
Cheers,
I would love to just put 87 in my 05 V8 but I can't do it. I have a problem!
They way I see it is this. I can put in 97 all of the time and if I find detonation move higher up the line.
or
Put in 91 and never have to worry about it. For me, it is 91 and no looking back.
Again,
It would be interesting to have some dyno results. (I'm pretty sure they would show under most circumstances that there is no power difference.)
I wonder though if you took random samples from 87 regular gas to see what the absolute octane rating is as there are many factors that could affect this outcome. Again, why I feel better buying 91.
Interesting though, I used to own a Honda Accord V6 Coupe and it had no knock sensor (87 in the owners manual) but I ran 91 on it all the time. Then later I read an article in Car and Driver where they tested several cars on different octane ratings and one of them was an Accord V6 and they found it was slower on 91 than it was on 87. Again, no knock sensor. There were several other cars though and I can't remember the outcome of the rest.
Anybody else read this article?
Cheers,
mikes4runner
New member
MacVay said:
Read people.....but the dead horse will still be beaten
24runners
New member
24runners said:
Also, TOYOTA RECOMMENDS at least 91 octane...I wonder why
"Test AWD V8 Sport averaged 15.5 mpg. No opportunity yet to measure with V6. Toyota recommends 91-octane premium fuel for both engines."
http://auto.consumerguide.com/auto/new/reviews/full/index.cfm/id/23334.htm
Even Boating Magazine says premium is recommended for both engines.
FROM MY 2005 TOYOTA OWNER'S MANUAL:
"For improved vehicle performance,the use of premium unleaded gasoline with an Octane rating of 91 or higher is recommended." -- page 282
pressroom.toyota.com recommends 91:
http://pressroom.toyota.com/photo_library/display_release.html?id=2003gx470_s
Not trying to "beat the dead horse" but no one has commented on the fact that Toyota actually recommends 91 or higher in the owner's manual.
I would like to think that there is some kind of reasoning behind this
And I agree with MacVay:
I can put in 87 all of the time and if I find detonation move higher up the line.
or
Put in 91 and never have to worry about it.
I'll choose the "never have to worry bout it" option
