I'm on Long Island, pretty much at sea level.
Frank D
Frank D
Question re: Octane requirements for new Toyota
- Thread starter demarpaint
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Did you reset the computer between the fill ups when you switch from 87 to 91?
If you don't, the engine computer will not adapt right away and ofcourse you'd see no gain from the higer octane gas.
"...
Did you reset the computer between the fill ups when you switch from 87 to 91?
If you don't, the engine computer will not adapt right away and ofcourse you'd see no gain from the higer octane gas...."
LOL! What kind of idea is that may I ask?
I've never heard of the call for resetting your computer everytime you switch octane gas??? And what about the use of knock sensor? Isn't the ECU going to auto-adjust to your octane????
Did you reset the computer between the fill ups when you switch from 87 to 91?
If you don't, the engine computer will not adapt right away and ofcourse you'd see no gain from the higer octane gas...."
LOL! What kind of idea is that may I ask?
I've never heard of the call for resetting your computer everytime you switch octane gas??? And what about the use of knock sensor? Isn't the ECU going to auto-adjust to your octane????
You do understand how ridiculous that sounds?
The ECU will advance the timing automatically. Sorry my recordkeeping does not jive with your preconceptions.
Yeah, but many Honda V6 engines run much better with 91 than with 87.
My take on the quote:
I would take on Porshe's stance RE: octane rating, more than GM's statement on their supercharged cars RE: knock sensor not fast enough causing detonation. In other words: if what GM said is indeed true then fault is on them/their designs, not others for knock sensor, ignition mapping, etc. on modern cars are so good/so fast, drivers typically cannot perceive that the knock-sensor/auto-adjusting of fuel octance and overall engine performance difference at all.
Now, back in year 2006: my friend has rented an MB B200 which called for 91 octane rating pump gas. Being a cheeparrse he was, he filled it numerous of times with 87 @Esso and no detrimental effects perceivable other than additional savings from using 87 octane gas.
Ditto with my 10.3:1 compression ratio Fit where 87 octane gas is being called for. Living in a hilly terrain, I tend to strain my car quite a bit and I have tried from 87 to 92 octane gas and so no perceivable gains at all (yes, it's L15 engine is fully computer managed with knock sensors and fully computerised idling/ignition mapping and control). In my previous Mazda B6 block with distributor, using 92 makes a perceivable gain in overall idle smoothness and such.
I would take on Porshe's stance RE: octane rating, more than GM's statement on their supercharged cars RE: knock sensor not fast enough causing detonation. In other words: if what GM said is indeed true then fault is on them/their designs, not others for knock sensor, ignition mapping, etc. on modern cars are so good/so fast, drivers typically cannot perceive that the knock-sensor/auto-adjusting of fuel octance and overall engine performance difference at all.
Now, back in year 2006: my friend has rented an MB B200 which called for 91 octane rating pump gas. Being a cheeparrse he was, he filled it numerous of times with 87 @Esso and no detrimental effects perceivable other than additional savings from using 87 octane gas.
Ditto with my 10.3:1 compression ratio Fit where 87 octane gas is being called for. Living in a hilly terrain, I tend to strain my car quite a bit and I have tried from 87 to 92 octane gas and so no perceivable gains at all (yes, it's L15 engine is fully computer managed with knock sensors and fully computerised idling/ignition mapping and control). In my previous Mazda B6 block with distributor, using 92 makes a perceivable gain in overall idle smoothness and such.
The only way you're going to settle your argument with yourself is to try 87 octane a while, and then try 93 (or 91). In my 2002 Sienna, the "sludge-machine," I have found I get better gas mileage by about 10% with 91-octane fuels. Maybe sometime I'll connect my OBD meter and experiment...
The price of higher octane fuel is about 10% higher, so price-wise, it's even for me. But consider the following: you're probably burning through less fuel; your engine head will possibly be slightly cooler; and detergency in some premium fuels is better (ie Mobil). That tips the balance for me.
Pete
2002 Sienna, 96000 sludge-free miles first on Cheveron Supreme, now on Mobil-1; using Redline SI-1; and I have snow tires on!
The price of higher octane fuel is about 10% higher, so price-wise, it's even for me. But consider the following: you're probably burning through less fuel; your engine head will possibly be slightly cooler; and detergency in some premium fuels is better (ie Mobil). That tips the balance for me.
Pete
2002 Sienna, 96000 sludge-free miles first on Cheveron Supreme, now on Mobil-1; using Redline SI-1; and I have snow tires on!
Something that you have to remember is that octane rating is an enumeration of a fuels resistance to pre-ignition. As a rule, the higher the octane, the less energy per unit in the fuel. This means that an 87 octane fuel has more energy per volume than a 91 octane fuel. The caveat is that you must use a fuel that is resistant enough to pre-ignition to prevent your engine computer from retarding ignition timing. This means that a vehicle designed for use with 87 octane fuel should get fewer mpg with a higher octane fuel. A modern car designed for 91 octane fuel will NOT be harmed by lower octane fuel, but will more than likely attain poorer fuel economy than with 91. That said, one must determine which fuel is more economical by determining average cost per mile using different octane fuels.
My turbocharged Saab 93 runs just fine on 87. The manual recommends 87 as a minimum but then goes on to say that 91 will give best performance.
I didn't notice any difference between 87 and 89, I haven't tried 93 yet.
It seems like fuel economy is slightly better with 87.
I didn't notice any difference between 87 and 89, I haven't tried 93 yet.
It seems like fuel economy is slightly better with 87.
bshockme-
No, octane rating has more to do with the ability to resist pre-ignition(it's a controlled burn) and absolutely nothing to do with energy contents.
In other words: the energy contents of 92 Octane pump gas is fundamentally the same as 87 pump gas.
We had this arguments before so here's the URL to clear things up:
http://theoildrop.server101.com/forums/s...part=1&vc=1
p.s. don't throw in those AviationGas into the picture for they should have little to nil to do with regular automobile pump gas.
Also: the common misunderstandings of Octane rating is that higher octane gas runs "cooler" which is also poppycock. The proper terminology (IMHO) to explain Octane is to think of it as "controlled" burn and not how "hot" or "cold" the charge burns.
No, octane rating has more to do with the ability to resist pre-ignition(it's a controlled burn) and absolutely nothing to do with energy contents.
In other words: the energy contents of 92 Octane pump gas is fundamentally the same as 87 pump gas.
We had this arguments before so here's the URL to clear things up:
http://theoildrop.server101.com/forums/s...part=1&vc=1
p.s. don't throw in those AviationGas into the picture for they should have little to nil to do with regular automobile pump gas.
Also: the common misunderstandings of Octane rating is that higher octane gas runs "cooler" which is also poppycock. The proper terminology (IMHO) to explain Octane is to think of it as "controlled" burn and not how "hot" or "cold" the charge burns.
Sinasta-
My Honda fit comes with 10.3:1 compression ratio. With knock sensor and dynamic computerised ignition mapping (controlled by ECU), I can run 86/87 octane rating w/o any problems (Honda manual recommends running 86/87Octane).I tried running 92Octane and absolutely no perceivable changes in fuel economy or "smoothness" from the engine.
My Honda fit comes with 10.3:1 compression ratio. With knock sensor and dynamic computerised ignition mapping (controlled by ECU), I can run 86/87 octane rating w/o any problems (Honda manual recommends running 86/87Octane).I tried running 92Octane and absolutely no perceivable changes in fuel economy or "smoothness" from the engine.
Again I post this www.toptiergas.com
Those fuel makers prevent deposits and keep your injectors clean as well as the entire fuel system regardless of what octane is used.
High(er) octane fuel is not cleaner then lower octane fuel, this is a fact. It is all about additives in the fuel.
Those fuel makers prevent deposits and keep your injectors clean as well as the entire fuel system regardless of what octane is used.
High(er) octane fuel is not cleaner then lower octane fuel, this is a fact. It is all about additives in the fuel.
With the gas mileage that the new toyotas get, I wouldn't mind putting good gas in them.
On the other hand, my mother owned a lincoln navigator that required premium fuel, that was such a waste of fuel.
On the other hand, my mother owned a lincoln navigator that required premium fuel, that was such a waste of fuel.
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