I've always ran the low grade, and at altitude it's 85. However, with the SC I do have to run premium. A trade I'm willing to make to be blown.
Regular or Supreme Gas?
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Based on the 1993 article about the "new" 1FZ's engine management system and my limited knowledge of octane and engines, this appears to be what's going on....correct me if I'm wrong....
Even though 9 to 1 compression seems low by today's standards, it's really not that low and most engines are only able to run on the standard octane gas, because the timing is retarded to prevent pinging and other issues, which is where power is lost.
The 1FZ with its duel knock sensors and new engine management system can run the higher octane fuel with the engine timing advanced and providing more power and possibly smoother operation, while the duel knock sensors prevent damage by sensor potential problems from all 6 cylinders. Since the engine can run more advanced, there is more power.
It's not about more energy or less energy in the different octane fuels giving more power, it's about whether or not the engine can run at peak effeciency and more advanced timing without risking damage.
Also, another thing to consider. Small piston aircraft gas engines use 100 or 130 octane fuel, yet have fairly low 6 or 7 to 1 compression ratios on many models.
By the way, my 22RE pings like a mad monkey on low octane fuel. But part of the problem, I'm sure, is carbon deposits on the pistons over the years, even though I've cleaned out the combustion chambers multiple times.
Even though 9 to 1 compression seems low by today's standards, it's really not that low and most engines are only able to run on the standard octane gas, because the timing is retarded to prevent pinging and other issues, which is where power is lost.
The 1FZ with its duel knock sensors and new engine management system can run the higher octane fuel with the engine timing advanced and providing more power and possibly smoother operation, while the duel knock sensors prevent damage by sensor potential problems from all 6 cylinders. Since the engine can run more advanced, there is more power.
It's not about more energy or less energy in the different octane fuels giving more power, it's about whether or not the engine can run at peak effeciency and more advanced timing without risking damage.
Also, another thing to consider. Small piston aircraft gas engines use 100 or 130 octane fuel, yet have fairly low 6 or 7 to 1 compression ratios on many models.
By the way, my 22RE pings like a mad monkey on low octane fuel. But part of the problem, I'm sure, is carbon deposits on the pistons over the years, even though I've cleaned out the combustion chambers multiple times.
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Just a rant but this is why the 3fe gets such bad power #'s, its hideously low compression ratio.
the last place the average complainer thinks to look at why its power is so low.....
And Brian, great post, and your 22RE problems also make me question your fuel quality in Oregon.
and cant you make wx3.brian894x4.com a link? You know, fer lazy people?
the last place the average complainer thinks to look at why its power is so low.....
And Brian, great post, and your 22RE problems also make me question your fuel quality in Oregon.
and cant you make wx3.brian894x4.com a link? You know, fer lazy people?
Shell's Regular, Plus and Shell V-Power® premium-grade gasolines all meet the “TOP TIER Detergent Gasoline” standard.
Shell Regular and Plus gasolines, which meet the “TOP TIER” standard, also contain more than two times the amount of cleaning agents required by the EPA.
Cheveron has Techron in all grades of fuel.
People can argue the benefits of premium in a vehicle that requires regular but even the gas companies white papers don't support that idea.
It's something that allows them to make more money though.
14 years running regular 87 octane w/o issues. Anything more in these beasts is just pissing your money away to the gas station owners. If you really feel like wasting the money, hit me with a PM and I'll give you my address or paypal account so you can send me the $4 every time you fill up if it will make you feel better. I promise to make good use of your money. Hell, I'd even declare it as income and pay tax on it, unlike the oil companies.
I'm shocked by how often this ridiculous suject comes up. Obviously the oil companies are billiantly brainwashing people into thinking that paying more for gas is better. But in the end, if people feel better by paying more, then let them.
The beauty of free market capitalism is that you can not only convince people to pay extra money, but that you can make them feel good about wasting that money. Especially since there is quite a bit of written data that suggests that running high octane in an engine that's not made for it can damage the engine. Oh well
The beauty of free market capitalism is that you can not only convince people to pay extra money, but that you can make them feel good about wasting that money. Especially since there is quite a bit of written data that suggests that running high octane in an engine that's not made for it can damage the engine. Oh well
From my research, the 1FZ is most likely designed to run at peak performance at an octane level of around 96+, not 87. (U.S. octane measurement, not RON) 87 is the minimum. It can run adequately on 87, because it has a superior knock sensing system, using twin knock sensors and a superior engine management system with wider parameters than most other engines, especially from that period, but is designed to run peak performance with a higher octane fuel.
With the higher octane fuel, the engine management system can advance the timing to a more efficient level without risk of detonation and this is where the increase in h.p., drivability and fuel economy comes from. The engine also probably runs slightly cooler.
Many engines with knock sensors will not advance the timing to the point of taking advantage of the higher octane fuel, even with similiar compression to our 1FZ, because the knock sensors are only for back up and the timing curve is still set conservatively to reduce the risk of detonation on low octane fuel, especially in conditions that promote knock, such as higher temps, etc. These engines are designed to run on around 87 octane or maybe slightly higher, but the engineers did not risk allowing the engine to advance the timing to a level that would require 91 or higher, because if the knock sensor failed to do it's job, engine damage could result, if the engine was only using 87. Its sort of a fail safe mode for an inferior engine management system.
But the 1FZ is a superior engine with a superior management system that was specificly designed to run a variety of fuels in a variety of conditions, since it was primarily a truck/commercial engine to be used all over the world in the 70 and 80 series Land Cruisers.
9 to 1 compression is actually not as low as some believe and all things considered, a 9 to 1 engine without engine management, will perform best on around 96 octane, but engine management systems, like the 1FZ, will allow the engine to run on lower octane fuel when that’s all that is available and run close to peak at a level lower than 96. Engines that have very high compression, like 10 or 11 to 1, even with engine management systems, are probably not taking full advantage of their potential even on 93 octane and probably could see signficant gains if running 100 or higher, assuming their engine managment systems are not limited and would be allowed to compensate.
Newer Toyota engines, that use similar systems to the 1FZ actually have in the owner’s manual, the following statement, even though they can still run 87 octane.
“For improved vehicle performance, the use of premium unleaded gasoline with an octane rating of 91 or higher is recommended.”
Whether the increased performance or mileage or engine longevity, whatever that amounts too, justifies the higher cost, is entirely another question. I have no idea. The difference between 87 and 91 is probably minimal, but if you started getting up to 93 or even 96, it might be fairly signficant. But most Americans are limited to around 91 or 92 at best, with some 93. Unless you used octane additives, which are pretty expensive.
But one thing is certain…the 1FZ definitely can take advantage of higher octane fuel, while running adequately and safely on a minimum 87. Many other engines cannot.
Here’s some VERY interesting reading here……
7. What parameters determine octane requirement?
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With the head shaved .030, fully desmogged, with max timing advance...I take full advantage of premium fuel.
Sorry, I was proved wrong about the detergents. I asked a tanker driver at Shell once, and he said that plus and premium have more detergents since premium has more and plus is a mix of the two. But he could be biased...
Sorry, I was proved wrong about the detergents. I asked a tanker driver at Shell once, and he said that plus and premium have more detergents since premium has more and plus is a mix of the two. But he could be biased...
.02 worth. My 97 FZJ80 is affected by the type of gas more than the grade. When I moved from Texas to Virginia, and started using gas with ethanol my MPG dropped to about 11. When I moved from Virginia to Florida and went back to gas without ethenol my MPG went back up to 14. I drive about the same distance with the same amount of stop and go.
Let's put this a different way.
I was asked to do this in racing off-road. Off-road racing uses cars on the longest sections of roads without any means of support.
In off-road endurance racing, you will run the longest on the lowest octane fuel that the car will run on without blowing up the engine. And so you design the engine to produce the most power out of the lowest possible grade of fuel. That is what the main auto manufacturers have worked for.
In newer technology, we have followed this model. We have reached a point where the increase of octane has no effect other than to increase wasted potential, I.E. hydrocarbons. When hydrocarbons are wasted, excessive heat is generated, causing harm to engines and other systems.
I was asked to do this in racing off-road. Off-road racing uses cars on the longest sections of roads without any means of support.
In off-road endurance racing, you will run the longest on the lowest octane fuel that the car will run on without blowing up the engine. And so you design the engine to produce the most power out of the lowest possible grade of fuel. That is what the main auto manufacturers have worked for.
In newer technology, we have followed this model. We have reached a point where the increase of octane has no effect other than to increase wasted potential, I.E. hydrocarbons. When hydrocarbons are wasted, excessive heat is generated, causing harm to engines and other systems.
So, everyone just wants to repeat the same old theory? Any comments on my post about how Toyota says that premium will produce more power and my comments as to why that probably is true?
By the way, why would anyone think that a race engine without things like knock sensors and in many casea any electronics at all, much less only needing to last one race or maybe one season, would be compariable to a mass produced automotive engine that needs to last (in Toyota's case) 200-300K miles and operate all over the world in various conditions using all types of petrol fuel?
By the way, why would anyone think that a race engine without things like knock sensors and in many casea any electronics at all, much less only needing to last one race or maybe one season, would be compariable to a mass produced automotive engine that needs to last (in Toyota's case) 200-300K miles and operate all over the world in various conditions using all types of petrol fuel?
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FWIW, my '94 with 150K does seem to idle smoother and get enough of a mileage increase to offset the extra cost of a tank of premium. Plus, as alkaline747trio mentioned, you can advance your timing a bit and get a little more power.
Lots of good information and bad mis-information going on here and it's all been beaten to death and resurrected and beaten again.
In any event I'll say that there is absolutely no question whatsoever that premium fuel is required for forced induction 1FZFE's. Not for the marketing, not for the additives (some of which work well actually), not for the extra economy (if there is any), not for the extra 'power' (if there is any) but simply for the delay in detonation. The thing about premium fuel for me at least is mostly over octane (although I admit I love Shell's premium additive package) and the amazing thing about octane (gross oversimplification offered here) is that the more you have in your fuel the less likely you are to pre-detonate within the combustion chamber. In a forced induction motor it is the difference between detonating on time and producing wonderful power or pre-detonating and grenading parts of the engine. In a normally aspirated motor it is the difference (sometimes) between all that pinging you hear, and all that pinging you don't. I guess for NA I'd just listen to the motor (literally); if it is pinging, well, go up a grade or two and see if it helps, and if it isn't pinging, don't. Pretty simple really so let's leave the poor horse lay now.
In any event I'll say that there is absolutely no question whatsoever that premium fuel is required for forced induction 1FZFE's. Not for the marketing, not for the additives (some of which work well actually), not for the extra economy (if there is any), not for the extra 'power' (if there is any) but simply for the delay in detonation. The thing about premium fuel for me at least is mostly over octane (although I admit I love Shell's premium additive package) and the amazing thing about octane (gross oversimplification offered here) is that the more you have in your fuel the less likely you are to pre-detonate within the combustion chamber. In a forced induction motor it is the difference between detonating on time and producing wonderful power or pre-detonating and grenading parts of the engine. In a normally aspirated motor it is the difference (sometimes) between all that pinging you hear, and all that pinging you don't. I guess for NA I'd just listen to the motor (literally); if it is pinging, well, go up a grade or two and see if it helps, and if it isn't pinging, don't. Pretty simple really so let's leave the poor horse lay now.
