Gas Octane

Yeah, I think I'm ready to unsubscribe from this thread. Every other week someone comes on claiming that it's all BS and that it makes no difference. I re-present my data and case for the 100th time, then they go away. 2 weeks later.... rinse and repeat. I'm done.

People should just run what they want. Nobody should bash people for their choices. That's my big pet peeve about it all.

I'm sure we all have personal decisions we make on a day to day basis that aren't always the most cost effective.

 

FINALLY!
Bashing people for their choices is what happens when they are presented in a public forum. Your choices in your house are private and not very bashable.

I love the way no one actually KNOWS WHAT SCIENTIFIC METHOD IS.
WHat we have here is anecdotal observation. Which is more like the idea that STARTS someone thinking about how to scientifically approach the problem to prove or debunk it.
The proper measurement practice has not been determined much less executed.

The result is a similar pile of argument to that when a researcher says "I think the moon is made of cheese" and CNN reports that it is and everybody wants some.. then the research comes back 5 years later proving otherwise. Or the opposite. I really don't care. I am sure, however, that no one here is capable of running a test that means anything.

 

Wait, the moon ISN'T made of cheese? damnit, there goes all my childhood dreams....

 

You've never actually tuned a EFI engine then. An extra 2-6* of timing is huge. Yeah you can watch timing or even the narrow ban o2 sensors of course it'll change. If you dial it in to run, let's say 4* where the regular stock map runs 2* you will see extra torqe and/or power depending where the ecu load cell is at that RPM. I know there are aditional, more agressive timing, fuel and VVTi maps in the ecu that it'll switch to once a high (richer) octane is detected.
But Infinus, I do totally agree with ya about posting one thing then 2 weeks later.... here we go again. Unsubscribed

 

Infinus - you're a great example of someone who has just enough information to be dangerous. You also do exactly as you preach not to do in your last post. What a joke - and I'm the one who is inept? Go back and find a post where I say the 1GR-FE engine won't produce higher horsepower when using 91 or 93 octane fuel instead of 87 octane. All of my posts, prior to your sarcastic piece of shit post, are relative to energy content of fuels with different octane ratings and how that relates to gas mileage. We are all real impressed with your explanation of how knock sensors work and the fact that you have a scanner. I agree your explanation is right. The 1GR-FE will retard timing to prevent engine knock - and this will give a very slight increase in horsepower. You know it is very slight - and even say so in a later post. I believe I have read that Toyota has said that the 1GR-FE will produce 239 HP instead of 236 HP at 5200 RPM if you use 91 or higher octane instead of 87. So, exactly how does that negate anything I said prior to your dumb post? It doesn't. There are people on here claiming significant mileage gains - solely due to using higher octane fuel. If you are only getting maybe 1-1.5% HP gain (and that is at peak HP at 5200 RPM - HP gain in the 1500-3500 RPM range where most driving is done would be even less) the mileage increase you would get would be unmeasurable without very , very tightly controlled tests (that old scientific method thing). Running three tanks at each octane rating and then throwing that out there as proof is a joke. That is what I was objecting to. Never said a word about ignition timing, anti-knock sensors, or very slight HP gains related to these things. I guess I should unsubscribe too - with all your "concrete data" (what a joke) and "dyno experience" - I don't have a chance. Seriously, do you really think you are getting an extra 10-12 horsepower with your 5-6 degrees of ignition timing adjustment from the anti-knock system? You should work for Toyota dude.

 

JWC - This will be my last reply here. I'll be the first to admit that I did exactly what I hate about message boards and let my emotions get involved. I apologize for any personal attack I made. You and a few others were being a little aggressive in your wording and I let it fire me up and say some things I regret.

Moving on past that I'm just going to drop the emotions and bashing. I think we both have an understanding of what's to gain and what's not. I do not support the notion that people are morons or idiots for choosing to buy premium vs regular. It's a choice. Whether the pay back is worth it is up to you. I've posted early in this very thread that I believe there to be ZERO mileage gains unless doing all city driving or towing, and even then, it's minimal. So I definitely agree on the mileage comments.

Other then that I think everything that can be said on this topic has been said.

Happy Tday.

 

Well crap Infinus - nuff said - you are a bigger man than I. My posts were probably too over the top - more emotion in mine than was necessary. No apology is necessary - at the very least I would owe you one too. I will remember to conduct myself with more decorum here in the future. Thanks - I know you are knowledgable about which you speak.

 

do what you feel.

if i am going on a road trip i put in low octane because i am just going to burn through a tank in a few hours anyway. if i am staying local for the week i put in high octane.

i definitely think the truck runs better on high octane but as long as i get from point "A" to point "B" without incident I really don't give a rats ass.

 

I have been running 87 octane in my 03 with the 5VZ. Just filled up and used 89 octane.

Bought the truck with no light and went about 7000 miles and the CEL came on. I'm not sure what the PO ran in the truck.

I heard that I might have a CEL (P0420) because of the ethanol levels in the fuel so i'm doing my homework right now to find out if thats true. I want my CEL gone

 

I can't imagine that ethanol alone would cause your CEL, otherwize 1/4 of the tacomas in the country would be having the same problem. All of New England runs on 10% ethanol, that's a lot of tacoma's right there.

 

What kind of numbers are we talking? I would make the change if this is proven on our trucks. JOE>

 

You need to run the numbers yourself, basically you need to calc $/mile or miles/$, instead of miles/gal.

As for "proven", seems to depend on driver and truck. Personally I haven't seen any mpg increase that I can attribute to Premium. All of my mpg changes can be attributed to driving style during the tank.

I have changed back and forth several times, but can't put any gains toward the fuel myself.

Others say they can and do, so you need to run the miles and numbers yourself.

 

Since I bought my truck I have ALWAYS put 91 octane from Shell. Always buy quality gas for a Toyota.

 

Dosen't the Manual say 87 or Higher ??Meaning Higher is ok??

 

Manual says 87 or Higher, so Manual is lying,Higher is bad, ok.

 

actually it would depend on the spark tables within the PCM or whatever you want to call the computer that controlls spark. I don't know anything about Toyota tuning but if it is like GM then there are two spark tables. One for driving normal with normal fuel and one that the computer can refer to with timing decreased if spark knock is detected.
Running any higher octane in a vehicle tuned for low test will offer no gains other than the extra additives the premium fuel might have. Now if you can alter your spark tables then you can take advantage of that higher octane by adding a few degrees of timing.

 

I really dont know where you got this info from. Higher octane definately makes the vehicle work more efficiently resulting in better acceleration and higher top end along with better torque. Maximum HP and Torque that any particular engine makes is under ideal conditions. Hi Octane fuel brings your engine closer ideal conditions. On top of that the Hi Octane fuels have more additives in them for cleaning injectors. I wonder why professional race drivers dont use 87 octane when they are running pump gas.

 

This is the most ridiculous thing I have ever heard. You are most definately out of your mind.

 

I'm sure this has been said, but if the manual says to use 87, then the engineers that designed and built the tacoma probably mapped the ecu to accept low octane fuel, and that's what you should run.

If you're running a boosted application of some type, and an engine management system to tune with, THEN it would be a great idea to run 91/93. All higher octane does is help prevent knock and detonation. If you want to think of it this way, when you run higher octane on a boosted setup, you can run more timing and more boost, therefore producing more horsepower.

As far as using the factory ECU and a stock truck to run higher octane fuel with, you're really not gonna see any hp gains from it.

 

lol, this thread has been great,

put it like this,,,,, mind over matter,,,,, if you put a difference of 4 octane numbers in and your truck dies,,,, then maybe its not the truck, but the driver.

also, weather and temp and humidity needs to be taken into account, as well as HOW WELL OR BAD MAINTAINED THE VEHICLE IS.
also, ,,, i personally never go to a gas station that i dont know and that i see getting the tanks filled,,, that just stirs up all the crap in the tanks in the ground.

pretty much its like this,,,,, the price differnece between 86 and 91 is so little that by the time you fill up you maybe have a difference of like 3 bucks,,,, .15 x 16 = 2.40 wow, so the people saying they are saving by getting the low grade,,,, 2.40!!!!!! BOOK THE CRUISE!!!!!!!

ask any dealership, read the owners manual,,, TOO MANY VARIABLES:
year, maintenance, weather, driving style, quality of gas, elevation, tires, what you ate for lunch, manual or automatic tranny, if you took your morning dump, your dogs head out the window

too many damn variable are take into account for any one person to say that 91 is better that 86, but really, look at the brand of gas, additives, and the internal condition of the motor.

but keep going, i like hearing ppl argue about myths..... ooooooooo maybe we should put in a suggestion to MYTHBUSTERS... they did that one episode about whether or not your tailgate up or down effects gas milage.