View Poll Results: 87, 89, 93?
Voters: 84. You may not vote on this poll
What type of fuel do you use?
04-27-2005, 04:00 AM
#21
Senior Member
SL Member
Join Date: Apr 2005
Posts: 125
hahah
had to throw that in ... wish i was you though with the free gas , but if i was i dunno if would have tradded in the (2000 jeep (paid off)) for my much loved scion !!!this wagon rocks ( tapping fingers waiting on wheels and tires and springs in the mail)
04-27-2005, 04:25 AM
#22
Senior Member
SL Member
Scinergy
Join Date: Aug 2004
Location: GA
Posts: 826
Re: hahah
Originally Posted by professor-xb
had to throw that in ... wish i was you though with the free gas , but if i was i dunno if would have tradded in the (2000 jeep (paid off)) for my much loved scion !!!this wagon rocks ( tapping fingers waiting on wheels and tires and springs in the mail)
04-27-2005, 04:45 AM
#23
Depends on how the basic curves for the engine are set up.
In one vehicle I had previously that was designed to run on 87 (and would probably run on anything from Vitalis to avgas) there was a noticible difference in running high octane fuels because it was designed to advance it's timing until just at the start of ping and hold it there. It adjusted the timing if each cylinder individually based on the knock sensor on that cylinder.
I doubt the Echo engine is designed/set the same way. I suspect it is designed for best performance with an 87 octane fuel, and the knock sensor is set as a 'safety' that will simply retard timing if knock is detected.
Then again, the only way to tell for sure, without getting the word from Toyota, is to dyno a stock engine on different fuels to see what happens.
Thing is, with multiple knock sensors (one per cylinder) and computer curves designed to do it, this little 1.5 *could* take advantage of higher octane fuels. We just don't know what the engineers did in this case.
In one vehicle I had previously that was designed to run on 87 (and would probably run on anything from Vitalis to avgas) there was a noticible difference in running high octane fuels because it was designed to advance it's timing until just at the start of ping and hold it there. It adjusted the timing if each cylinder individually based on the knock sensor on that cylinder.
I doubt the Echo engine is designed/set the same way. I suspect it is designed for best performance with an 87 octane fuel, and the knock sensor is set as a 'safety' that will simply retard timing if knock is detected.
Then again, the only way to tell for sure, without getting the word from Toyota, is to dyno a stock engine on different fuels to see what happens.
Thing is, with multiple knock sensors (one per cylinder) and computer curves designed to do it, this little 1.5 *could* take advantage of higher octane fuels. We just don't know what the engineers did in this case.
04-27-2005, 06:02 AM
#24
Senior Member
SL Member
Join Date: Apr 2005
Posts: 134
Well put, Tomas. If the knock sensor is only there as a safety, we get what we get, and that's 108 HP on 87 - or any other octane - and that only under ideal conditions.
Hopefully, that's not the case. I'd be surprised if Toyota added the sensor and related software just as a safety, but maybe so. At the least, it eliminates potential customer complaints about knocking and/or any requirement for high octane, at not much cost to Toyota.
I'll try the good stuff soon and see if I notice any difference, particularly in the "lugging zone" - ~2000-2500 RPM on a grade.
Hopefully, that's not the case. I'd be surprised if Toyota added the sensor and related software just as a safety, but maybe so. At the least, it eliminates potential customer complaints about knocking and/or any requirement for high octane, at not much cost to Toyota.
I'll try the good stuff soon and see if I notice any difference, particularly in the "lugging zone" - ~2000-2500 RPM on a grade.
04-27-2005, 06:55 PM
#25
Senior Member
Music City Scions
SL Member
Join Date: May 2004
Location: West TN - Land of twisty roads
Posts: 11,808
I've tried multiple grades of fuel at different times and it didn't make enough difference to make it worthwhile. Performance and fuel milage didn't go up or down depending on the octain rating so if you do use the more expensive stuff you are just throwing money away. Nuf said.
04-27-2005, 07:37 PM
#26
Senior Member
SL Member
Join Date: Apr 2005
Location: Miami, FL
Posts: 1,834
Re: knock sensor
Originally Posted by gslippy
Originally Posted by jethro b
Originally Posted by gslippy
The 1.5L engine is equipped with a knock sensor, whose function is to retard the ignition timing when it detects knock as an acoustic signal. Knock is the sound of the igniting gas charge trying to push the piston backwards in the cylinder, and will occur under the wrong combination of load, throttle opening, and fuel octane.
High octane gas (93) actually burns more slowly than low octane gas (87), and so the power delivery to the piston is more smooth, reducing the tendency to knock under similar load conditions.
The knock sensor is designed to eliminate the knock altogether regardless of the fuel used. This is a great mass-market idea, and eliminates lots of customer complaints to their dealers. Many cars are fitted with knock sensors. Only those that are so fitted will benefit from higher octane gas (unless you can manually advance the ignition timing), and the 1.5L is one of them.
Since the 1.5L is fitted with a knock sensor, I'd be very surprised if anyone has ever heard one ping for more than a second or two.
High octane gas should provide MORE power because it delivers the power over a broader angle of shaft rotation than does low octane gas. You could experiment with the higher octane stuff and see if it makes any difference in power or economy. With the relative price difference between the fuel grades fairly small now, I'd suggest trying it out.
High octane gas (93) actually burns more slowly than low octane gas (87), and so the power delivery to the piston is more smooth, reducing the tendency to knock under similar load conditions.
The knock sensor is designed to eliminate the knock altogether regardless of the fuel used. This is a great mass-market idea, and eliminates lots of customer complaints to their dealers. Many cars are fitted with knock sensors. Only those that are so fitted will benefit from higher octane gas (unless you can manually advance the ignition timing), and the 1.5L is one of them.
Since the 1.5L is fitted with a knock sensor, I'd be very surprised if anyone has ever heard one ping for more than a second or two.
High octane gas should provide MORE power because it delivers the power over a broader angle of shaft rotation than does low octane gas. You could experiment with the higher octane stuff and see if it makes any difference in power or economy. With the relative price difference between the fuel grades fairly small now, I'd suggest trying it out.
It's a tiny 1.5 4 cyl. making a whole 108 hp. the only thing that will really help it make some additional hp is a turbo or blower. Even then it may only need mid-grade fuel. Got it now 
You'll note that I never said that you'd realize any great gains from running higher octane fuel. You'll also note that I never said you NEED anything better than 87 octane. However, you WILL realize more power from an engine fitted with a knock sensor AND running higher octane fuel than one without those things.
The shop manual states that "During Fail-Safe mode, the ignition timing is retarded to maximum retardation". Perhaps you've never set the ignition timing on an engine, or understand how to actually improve power in an engine, but the purpose of the knock sensor is to maximize power in the engine with the fuel it is given, without permitting it to knock. Knock is extremely destructive to an engine.
Toyota didn't fit these engines with knock sensors just for fun. It's there so that you can get every bit of power the engine has to offer without destroying itself. Many manufacturers list their horsepower based upon using premium fuel. Such engines have knock sensors. Toyota has chosen to rate this engine at 108 HP on 87 octane. This engine with a faulty knock sensor will still develop 108 HP on 87 octane, and nothing more with 93 octane. But this engine should develop more power (how much, I don't know, but maybe 5 HP), if running on higher octane gas with a functioning knock sensor. If Toyota just wanted this engine to never knock, they could have retarded the basic timing curve to a very conservative setting, but instead they wanted it to develop some usable power for this application without the need for premium fuel all the time.
Of course this isn't a big-block with 11:1 compression. I'm just explaining the fundamentals of engine performance as it relates to fuel octane and knock sensors. Whether you want to spend the extra 20 cents on premium gas for a few extra HP is up to you. Such fuel may also get you better fuel economy because the power output is up for a given fuel delivery rate. Again, the tradeoff is up to you.
As I said in my prior post, I'd be surprised if any 1.5L has knocked on any octane fuel, because of the knock sensor. The only time you prevent knocking with higher octane gas is on a vehicle NOT fitted with a knock sensor, and whose ignition timing is overly advanced for 87 octane. So if you prefer to limit the engine to 108 HP on 87 octane and save your money, that's your choice.
As McBain said above, the knock sensor lets the engine run at peak efficiency just under the knock threshold. Peak efficiency means peak HP for the given load, because you're wasting less energy and gaining maximum power, which is the definition of efficiency.
Have any of you run this engine on a dynamometer to prove that high octane fuel is worthless in this engine?
-Ever notice how your car runs sweeter in cool, wet air? Or in the rain? The excess of moisture in the intake air has a modifying effect on the speed of the combustion process. This is quite noticable, and has been noted and exploited by aftermarket gadget makers since the dawn of automotive history.
The molecules of water vapor seem to act like spacers, having high heat adsorbtion, perhaps.. and so, slow down the progression of the flame front by some large number of microseconds. Result: A better push on the piston crown over larger number of crank rotation degrees, as gslippy noted.
Also in the formula: compression ratio vastly affects speed of the combustion. More on that later if interest is there.
04-27-2005, 09:14 PM
#28
Senior Member
Music City Scions
SL Member
Join Date: May 2004
Location: West TN - Land of twisty roads
Posts: 11,808
SciFly 
I'm glad you have $'s to waist on gas.(as if it didn't already cost too much) 
I'll spend my savings on mods and have the same performance as you with my 87 octain It's only money right 
I'm glad you have $'s to waist on gas.(as if it didn't already cost too much) I'll spend my savings on mods and have the same performance as you with my 87 octain It's only money right
04-27-2005, 10:13 PM
#30
Junior Member
Thread Starter
Join Date: Apr 2005
Location: Northern VA
Posts: 6
My original main reason for this post was to see if running 93 would hurt the engine. Even with "throwing away" the extra $.20 it appears that some say it won't hurt and will help regardless of the fact that it won't help in leaps and bounds. Not sure how the "jerk at work" is smarter than me as no one has stated that it will hurt the engine. Not to mention the fact that he wrote the post calling himself that.
04-27-2005, 10:23 PM
#31
Senior Member
Music City Scions
SL Member
Join Date: May 2004
Location: West TN - Land of twisty roads
Posts: 11,808
Originally Posted by bryanhoss
My original main reason for this post was to see if running 93 would hurt the engine. Even with "throwing away" the extra $.20 it appears that some say it won't hurt and will help regardless of the fact that it won't help in leaps and bounds. Not sure how the "jerk at work" is smarter than me as no one has stated that it will hurt the engine. Not to mention the fact that he wrote the post calling himself that.
04-27-2005, 10:45 PM
#33
Junior Member
Thread Starter
Join Date: Apr 2005
Location: Northern VA
Posts: 6
So I spend an extra $100 annually for gas. Whoopty doo. Maybe most of you are right. I should drop to 87. While I'm at it, I can just drop the insurance on it. That'll save me $1200 annually since I don't use it (the insurance). Never wash it again... that'll save some time and money. Oooh Oooh! I'll never eat out again. From now on its Ramen Noodles. No more beer! No more soda! No more pizza! Hell, I'm gonna be rich.
04-27-2005, 10:55 PM
#35
Senior Member
Music City Scions
SL Member
Join Date: May 2004
Location: West TN - Land of twisty roads
Posts: 11,808
Originally Posted by bryanhoss
So I spend an extra $100 annually for gas. Whoopty doo. Maybe most of you are right. I should drop to 87. While I'm at it, I can just drop the insurance on it. That'll save me $1200 annually since I don't use it (the insurance). Never wash it again... that'll save some time and money. Oooh Oooh! I'll never eat out again. From now on its Ramen Noodles. No more beer! No more soda! No more pizza! Hell, I'm gonna be rich.
04-28-2005, 02:46 AM
#37
Senior Member
Music City Scions
SL Member
Join Date: May 2004
Location: West TN - Land of twisty roads
Posts: 11,808
Originally Posted by bryanhoss
I already give to charity. What's your next idea?
Just stop telling other people that there is a benefit to burning premium when there really isn't. Remember if people hear enough BULL$HIT they start to believe it. I can't help that 20 percent of the people in the poll are flushing money down the drain and making the oil companies richer. Some have more money than they know what to do with.
04-28-2005, 05:19 AM
#38
Senior Member
SL Member
Join Date: Apr 2005
Posts: 125
Originally Posted by jethro b
Originally Posted by bryanhoss
I already give to charity. What's your next idea?
Just stop telling other people that there is a benefit to burning premium when there really isn't. Remember if people hear enough BULL$HIT they start to believe it. I can't help that 20 percent of the people in the poll are flushing money down the drain and making the oil companies richer. Some have more money than they know what to do with.p.s. i bet jethro b has a grounding kit installed... AND OMG
A "electric supercharger" hahahahah
04-28-2005, 05:49 AM
#39
Senior Member
SL Member
Join Date: Jul 2004
Posts: 109
I would suggest before calling BULL$HIT on people to do a little research so you know what you're talking about -- to quote Shell Canada's website (http://www.shell.ca/code/motoring/tips/gasoline.html):"Engines in vehicles built for sale in North America are designed to a specified octane requirement to make sure they don't knock or ping (engine knocking reduces the amount of power it can deliver to turn the wheels). Once that octane level has been met, in normal instances your car will not experience more power or better mileage if you use a higher octane fuel.
In other words, if your Canadian vehicle owner's manual specifies an octane rating of 87, running on gasoline with an octane rating of 89 or 91 or more will normally not make a difference.
However, there are some exceptions to this, and it must be noted that if the owner’s manual specifies using gasoline with an octane rating of 89 or 91, then that’s what you should use because that’s what the engine is designed and tuned for.
One - and a very important - exception is that when a vehicle gets older, the normal build-up of fuel- and lubricant-related deposits in the engine can increase the fuel octane number a car requires to prevent engine knock. For this reason, if a car more than a couple of years old experiences engine knocking, the problem may be solved simply by moving to the gasoline with the next-higher anti-knock index.
You will also benefit from a higher octane rating if:
the engine is knocking on the gasoline you are using, or
you have knock sensor ignition that can take advantage of higher octane values at times of peak demand, or
high summer temperatures, mountain driving, pulling heavy loads (including loaded roof racks) has temporarily increased your engine’s anti-knock index requirements.
While fuel with a higher octane rating cannot of itself deliver more power, in the above circumstances it can give an engine a greater ability to resist knocking, thereby helping it to deliver the full measure of power it is designed and tuned to provide.
In these cases, where drivers require their vehicles to continue providing peak performance despite challenging driving conditions, for improved responsiveness we recommend using a mid-grade fuel like Shell Silver (octane rating 89) or a premium fuel like Shell Optimax Gold (octane rating 91) gasolines.
One other exception is found in high-performance vehicles. The use of more complex computer algorithms in their engine control systems to control spark timing using one or more knock sensors, enables better performance on higher-octane fuel. Owner’s Manuals for most of these vehicles will specify use of 91 octane fuel."
So while you're right that the octane rating in and of itself in normal circumstances won't provide an improvement when using higher octane gas in a vehicle, there are a number of exceptions where there is an improvement (gslippy's knock sensor equipped engines example being one). Laugh all you want, but you're wrong, and I can tell you flat out that here in PA where we got long, steep ___ hills, there most definitely is a noticeable difference between 87 and 93 oct when climbing them. You can argue all you want, but you're not gonna one-up a company that makes gasoline.
04-28-2005, 06:20 AM
#40
Senior Member
Music City Scions
SL Member
Join Date: May 2004
Location: West TN - Land of twisty roads
Posts: 11,808
Originally Posted by Chikubi
I would suggest before calling BULL$HIT on people to do a little research so you know what you're talking about -- to quote Shell Canada's website (http://www.shell.ca/code/motoring/tips/gasoline.html):"Engines in vehicles built for sale in North America are designed to a specified octane requirement to make sure they don't knock or ping (engine knocking reduces the amount of power it can deliver to turn the wheels). Once that octane level has been met, in normal instances your car will not experience more power or better mileage if you use a higher octane fuel.
In other words, if your Canadian vehicle owner's manual specifies an octane rating of 87, running on gasoline with an octane rating of 89 or 91 or more will normally not make a difference.
However, there are some exceptions to this, and it must be noted that if the owner’s manual specifies using gasoline with an octane rating of 89 or 91, then that’s what you should use because that’s what the engine is designed and tuned for.
One - and a very important - exception is that when a vehicle gets older, the normal build-up of fuel- and lubricant-related deposits in the engine can increase the fuel octane number a car requires to prevent engine knock. For this reason, if a car more than a couple of years old experiences engine knocking, the problem may be solved simply by moving to the gasoline with the next-higher anti-knock index.
You will also benefit from a higher octane rating if:
the engine is knocking on the gasoline you are using, or
you have knock sensor ignition that can take advantage of higher octane values at times of peak demand, or
high summer temperatures, mountain driving, pulling heavy loads (including loaded roof racks) has temporarily increased your engine’s anti-knock index requirements.
While fuel with a higher octane rating cannot of itself deliver more power, in the above circumstances it can give an engine a greater ability to resist knocking, thereby helping it to deliver the full measure of power it is designed and tuned to provide.
In these cases, where drivers require their vehicles to continue providing peak performance despite challenging driving conditions, for improved responsiveness we recommend using a mid-grade fuel like Shell Silver (octane rating 89) or a premium fuel like Shell Optimax Gold (octane rating 91) gasolines.
One other exception is found in high-performance vehicles. The use of more complex computer algorithms in their engine control systems to control spark timing using one or more knock sensors, enables better performance on higher-octane fuel. Owner’s Manuals for most of these vehicles will specify use of 91 octane fuel."
So while you're right that the octane rating in and of itself in normal circumstances won't provide an improvement when using higher octane gas in a vehicle, there are a number of exceptions where there is an improvement (gslippy's knock sensor equipped engines example being one). Laugh all you want, but you're wrong, and I can tell you flat out that here in PA where we got long, steep ___ hills, there most definitely is a noticeable difference between 87 and 93 oct when climbing them. You can argue all you want, but you're not gonna one-up a company that makes gasoline.
This topic is just going round and round and some people just don't get it and that is fine. Just keep spending $$$'s on fuel you don't need. The oil companies don't care and neither do I anymore. See if I try to help anymore! And to those 20 % "Bless Your Hearts" Your Special!
especially professor_xb