Gas Octane

My truck runs much better on 93.

 

Ok so do my truck benefits from 91 or not...

All this is confusing.

Some are saying that the engine is not and never was tuned for 91, others say that it was/is.

Using 91 in an engine tuned for it would lead to some fuel economy due to more timing advance.

 

Our trucks will adjust to whatever octane you use. Some say that higher octane is a waste and other do not. You need to do your own experiments. The higher octane will not damage your engine, it is just a personal preference.

 

The engine was designed and tuned for 91. It has knock sensors that will retard power if 87 octane is used.

It can run just fine on either. In daily driving there will be no difference except for the smoother rev with 91/93. In order to take advantage of the extra power, you'd have to first max out what is provided by 87, which no one does daily driving.

In other words, the only benefits of premium are if you push the engine to its limits.

 

Ha ha ha ha... holy shit... you guys don't have a clue

 

Why do some of you get so pissed off about what the others write? Just sayin', its a semi-free country, why do you care if I want to pay $4 or $5 extra per tank?

 

I have a clue that I can READ in my 06 manual that 87 (91RON) is fine BUT 91(96RON) will give you better performance.

So your claim that it has NEVER been said in a tacoma manual that using anything higher than 87 will give you better performance or MPG is complete CLUELESS BS. Just read the first page of this thread specifically post #2 and #17.

Also, not sure if premium makes a bit of difference but I get great MPG in my access cab v6 offroad 4X4 (21-24) avg. 22-23. running shell 91 Octane. Stock pickup with leer shell 265/75/16 AT tires. I only fill up twice a month anyway so I really dont care about the extra $4.00 at fillup.

 

From Down Under I fill up with Shell V Power 98 Octan. We don't have the Tacoma here but have the same engine as the Tacoma the 1GR-FE V6 in
the Toyota Prado which is equipt with two tanks total fuel capacity of 180 litres or 47.55 US Gallons and at $1:40+ a litre it's a expensive exercise on pay day to fuel up. Since running on the the higher octan fuel I do get better fuel economy and better for the engine in the long run.

Attached is some info found on one of our forums from Australia

[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]High Octane Fuel[/FONT]

Let’s look at why this is - in an effort to help members understand how their petrol engine adapts to varying fuel quality.

Briefly, a petrol engine requires fuel to be injected at the right time and a spark to be generated at the spark plug at a precise point in the compression cycle. Fuel then burns in a controlled fashion generating lots of good energy to push the piston and ultimately drive the car.

If that spark is generated a little bit later in the compression cycle (retarded ignition timing), combustion is less efficient resulting in less power and torque.
Conversely, if that spark is generated a little bit earlier in the compression cycle (ie advanced ignition timing), fuel combustion occurs in an explosive fashion commonly referred to as detonation or pinging. This can lead to engine damage.
Generally the optimum ignition timing is advanced to a point just before the onset of detonation (in most engines). This results in the highest efficiency and results in the maximum amount of power and torque.

The higher the fuel octane rating, the less prone it is to detonation, hence the greater potential for ignition timing to be advanced further. – Again resulting in higher efficiency. However, we have no control over the ignition timing advance as it is adjusted by the engine management system.

In recent years, Toyota had been quite proactive in adopting advances in engine management and implementing them on the Toyota 4WD range. One of these advances was an ignition advance system that slowly advanced ignition timing to the point where minor detonation would occur and was registered by the engine knock sensors. The engine management system would then retard the ignition timing slightly and after a period of time without further detonation, slowly advance timing again. This ensures that the engine runs as efficiently as possible given the fuel quality available. The tuning industry’s term for this adaptive system is one that “runs on the knock sensors”.

This is not to be confused with less advanced systems that run a predetermined ignition advance map and use the knock sensors as a safety precaution to retard only when serious detonation occurred.
1GR-FE petrol engines are equipped with adaptive ignition timing however the rate at which the timing advances is very slow indeed. In addition, if even minor detonation is registered at one part of the RPM range, the entire ignition map is retarded across the entire RPM range.
When high octane fuel is used, the likelihood of detonation is diminished and the engine management system can advance the ignition timing further than that with standard fuel. Resulting in higher efficiency, greater power and torque as well as reduced fuel consumption.

However, in the range of petrol engines, the rate of ignition advance is very slow indeed. This means that one needs to run high octane fuel for many km before any change in performance or economy is fully realised. In the case of the 3.4L V6, 5,000 – 7,000 km and for the 4.0L V6 , 3,000 km – 5,000 km.

Generally after one or two tanks full, the owner will give up and return back to standard fuel because he notices no difference – and does not realise that it takes so long. However if you persist, the benefits are real and quantifiable – more so in terms of fuel economy.

Fuel economy with standard unleaded was consistently 15.5 l/100km. However, with 98 RON Shell Optimax, fuel economy is consistently 13.1 l/100km – a reduction of 2.4 l/100km or in percentage terms, a reduction of 15.5% in fuel consumption. This incidentally is greater than the price difference between standard unleaded and Optimax, so in this case, running the better quality fuel results in an overall saving in fuel bills, extended range – and of course the additional engine performance is free!

The secret is though to persist with the better quality fuel for a long period of time.

 

JWC - Honestly, your attitude is ineptness in the extreme. Ohhh, you have a degree, too bad you aren't using it.

1) 87 octane vs 93 octane, 93 might have less energy - this is true
2) 93 is capable of producing more power through efficiency - I have a scanner, do you? If you do, hook it up, look at it, use your brain, and you'll figure out how wrong you are. This engine RETARDS TIMING on 87 PERIOD. I don't care what any of you say, it RETARDS TIMING on 87. Is this bad? No, and the engine does not 'knock.' Does this produce LESS POWER, YES! I get a CONSTANT 5-6 degrees of ignition timing retarded on 87. I don't get any with 93. This is a FACT. I have concrete evidence, do you? Or do you want to keep incorrectly applying your theories? In my dyno experience, a degree of timing is usually worth a couple horse power give or take (depending on conditions).
Lastly, it has been shown TIME AFTER TIME, that the Tacoma manual has in fact stated that 93 octane vs 87 octane WILL PRODUCE MORE POWER!

Stop bashing people for their choices. I run 87 most the time, but 93 DOES MAKE A DIFFERENCE. If you "know" otherwise, hook up your own damn scanner and prove yourself wrong, because you are.

 

As long as you use the "might" you can say its true as it makes your "true" invalid to use might. your engine can not get the energy out of that octane. Its not high enough compression. Do any of you know what an octane is? the actual molecule? What it is and does to fuel. Octane does not in any way relate to the fuel's energy any more than any other molecule in the damn gas mix. Its a big soup of "anes".
I can't believe on every freaking car forum someone brings this up. They just can't believe that their car is built to use something with a lower number than something else.
The ONLY reason the other octanes are there are for certain high performance cars (usually forced induction) and old leaded fuel vehicles (converted to hardened seats) and to get suckers to pay more for what IS the same gas as far as your car is concerned.

It takes seconds to read any article about this yet forums just have to do a bunch of locker room "science" arguments that always include deceit and misinformation. I swear some posts are so damn wrong they have to be malicious.

If your car is detonating on low octane, you're either getting bad gas (not truly that octane rating or other unstable molecules in their mix), your car is broken or dirty (variable timing broken or super charged), or you're on a planet with much higher atmospheric pressure than earth. Its NOT an argument its a freaking fact! If you're observing something different you're doing it wrong.

 

I didn't say my car was detonating, I said it pulls timing. If you are so big on reading articles, read how knock sensors work. They listen for the audible signs of pre-detonation and pull back timing BEFORE an engine is knocking/detonating in a manner to damage itself. I have a completly stock car and I'm giving you hard evidence on how it runs. More so, you have further evidence that Toyota themselves have in the past stated as fact that the engine performs better on 92. So let me ask you this. Who's more of the ass clown here. The guy that is preaching knowledge through reading articles? Or the ones that have concrete, scientific data. I've scanned my car, if you think I'm doing it wrong, do it yourself and PROVE me wrong. I'm arguing with factual data, not what I've read online. And yet you preach to me that the situation is reversed? There's no locker room science going on here.

FACTS:
1) Toyota in previous years manuals stated this engine performs better on higher octane
2) This engine pulls a small amount of timing on 87 octane fuel

I didn't read these things online, I've seen the manuals that state this. I've seen my truck engine do this. No pseudo science, just PURE, FACT.

If you want to continue to argue with this, you are the one that comes off as dim witted and oblivious. Someone mentioned the "scientific method." Why don't you follow it yourself? Stop quoting what other people have said, find out for yourself. Buy a scanner. Put up or shut up.

 

On another note, let me add this. I'm not sure how many of you have experience with GM engines, but I can tell you right now from my past programming experience with them, that many of them come from the factory setup with aggressive timing maps that rely on the knock sensors to tame them. Just about all the higher end models that "recommend" premium. You don't have to run premium in them, they are setup the same as these Toyota trucks. The timing map is aggressive enough to get more from higher octane, and the knock sensors pull it back when you run 87.

 

One thing that I haven not seen mentioned is that in my area 87 has ethanol and 93 does not. That is why I run 93.

 

Ethanol alcohol is made from distilling starch and sugar crops. There's different % of ethanol in gasoline that can be burned. E10 is what's found in most fuels you buy now a days which is 10% ethanol. E10 leaves more deposits and lowers mpg but does have good knock deturent for high timing, compression or forced induction engines. E85 has 85% ethanol. Running E85 is about the equivalent running 110+ octane gasoline but requires larger amounts of the fuel due to its faster burn rate. Just because ethol alcohol burns faster doesn't mean it burns cleaner.

 

anyone that says it gives you more power and hp is BS. unless you made a performance modification that requires you to run a higher octane then i would say its alright.

if the manufacturer says to use a certain octane fuel, then i"ll use that octane fuel since the engine was designed to run on the particular octane and perform its best that way. But if you wanna spend the extra money so you "think" your getting more performance out of the truck than go for it. its your money

 

There is no think in this, Toyota HAS said that it gives you more power, they've removed this from their manuals however in recent years probably to simplify things. Emperical evidence and data also proves the compression on this engine is high enough to use higher octane fuel. This is a complete and utter loosing battle. Nobody is willing to actually think and use the data that's being presented. At the 6 cyclinder's compression ratio, timing map, programming, full timing advance is only attained with higher octane fuel. On regular, you loose between 2-6 degrees of timing. Higher octane produces more power, period.

Again, as I said though, nobody wants to look at the emperical data I've presented. Nobody has presented any of their own data other then, I read this, I believe this.

At the same time I'm stating my case here, I want to be clear that I personally run 87 because I don't think it's worth any said performance gains. It's a truck, I run the cheap stuff. But the evidence, Toyota, and all logical thinking supports that a small amount more power is available out of the 6 cyclinder in it's current incarnation. You gain 2-6 degrees of timing. No vast library of internet data that's out there can contradict the factual data.

 

Now, if you want to argue that the 2-6 degrees of timing advance that is gained using higher octane fuel DOESN'T actually result in more power, that might be it's own argument. But the fact remains that I can use a scanner, and measure 2-6 degrees of change in timing after running through a full tank of one gas or the other.

 

run 94 up here at husky

 

I wonder how many original posts are actually in this 23 page thread? Seems like a lot of people just keep saying the same thing?

 

93 FTW! Damn AZ. for not having it.