We use 92 now. Using regular in our Avalon the car was sluggish and hesitated from day 1 when we bought it in 2005. We also noticed better gas mileage with premium over regular. The same with the 2014 Tacoma and I noticed going up the same hill everyday that on regular gas, the transmission downshifts trying to maintain the same speed vs. premium gas, the truck hardly downshifts and cruises going up.
I'm done with low octane fuel
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Looks like many Japanese cars are designed to use higher octane fuel than recommended in manuals. Though, I doubt this assumption applies to all cars on the market. But It may explain why Toyota had sludge problems in some models.
Originally Posted by Ded Mazai
Looks like many Japanese cars are designed to use higher octane fuel than recommended in manuals. Though, I doubt this assumption applies to all cars on the market. But It may explain why Toyota had sludge problems in some models.
Interesting, my 1MZ-FE is one of the "sludge" motors and recommends a 91 or higher octane rating with 87 required. What connection are you referring to between octane rating and the formation of sludge in these engines?
Looks like many Japanese cars are designed to use higher octane fuel than recommended in manuals. Though, I doubt this assumption applies to all cars on the market. But It may explain why Toyota had sludge problems in some models.
Interesting, my 1MZ-FE is one of the "sludge" motors and recommends a 91 or higher octane rating with 87 required. What connection are you referring to between octane rating and the formation of sludge in these engines?
Lower octane increases piston, piston rings, cylinder walls temperature. Also ethanol exacerbates the problem. The sludge problem was limited to the USA where very low octane fuels like 87 (about 91-92 RON) are common. In Europe, the lowest octane is 95 RON (90-91 AKI) and the sludge problem is very-very rare. I doubt they allow more than 5% ethanol in fuels.
Having spent countless hours tuning many different fuels on many different engines, I haven't seen any difference in valve deposits, pistons/ring deposits, or oil loss/evaporation past the rings with different fuels of the same ethanol content. Running cheap 87 octane and VP-110 unleaded both showed the same exhaust gas temperatures (EGTs). The leaded race fuels like C16 ran 50-75*F hotter while high ethanol fuels like E85 ran 150-200*F cooler EGTs at max power air/fuel ratio. I've torn down quite a few engines run on E85/E98 that were squeaky clean inside.
A common issue with a few of these E85 cars in colder months/climates is coolant temperature. Because of the cooling factor of ethanol, the cars struggle to get even a little bit of heat in the cars before pulling onto the track. Most of them run small motorcycle sized radiators or no radiator at all.
I have seen one issue with sludge in an engine where the owner was using the cheapest conventional 20w-50 he could find, only changing it once a year (about 150 1/4 mile passes) and running E85. With 30+% more fuel comes more fuel dilution in the oil. He'd run that oil all season and then let it sit through the winter, only changing the oil before the first race come spring. With more fuel being used, fuel dilution will go up, so the oil must be changed more often. Another factor is the spark plugs used with ethanol fuel. Ethanol absorbs a lot of heat so a hotter plug is necessary to keep it clean. A common mistake in the racing world is people will run E85 at .82 lambda and -9 or -10 NGK plugs trying to tune it like a gas engine, then they get fouled plugs, hard starts, and hesitation. Running them on -7 plugs and .70 lambda netted more power and cleaner burn. It's a highly oxygenated fuel so you can't treat it like gasoline.
A common issue with a few of these E85 cars in colder months/climates is coolant temperature. Because of the cooling factor of ethanol, the cars struggle to get even a little bit of heat in the cars before pulling onto the track. Most of them run small motorcycle sized radiators or no radiator at all.
I have seen one issue with sludge in an engine where the owner was using the cheapest conventional 20w-50 he could find, only changing it once a year (about 150 1/4 mile passes) and running E85. With 30+% more fuel comes more fuel dilution in the oil. He'd run that oil all season and then let it sit through the winter, only changing the oil before the first race come spring. With more fuel being used, fuel dilution will go up, so the oil must be changed more often. Another factor is the spark plugs used with ethanol fuel. Ethanol absorbs a lot of heat so a hotter plug is necessary to keep it clean. A common mistake in the racing world is people will run E85 at .82 lambda and -9 or -10 NGK plugs trying to tune it like a gas engine, then they get fouled plugs, hard starts, and hesitation. Running them on -7 plugs and .70 lambda netted more power and cleaner burn. It's a highly oxygenated fuel so you can't treat it like gasoline.
Originally Posted by Ded Mazai
Lower octane increases piston, piston rings, cylinder walls temperature. Also ethanol exacerbates the problem. The sludge problem was limited to the USA where very low octane fuels like 87 (about 91-92 RON) are common. In Europe, the lowest octane is 95 RON (90-91 AKI) and the sludge problem is very-very rare. I doubt they allow more than 5% ethanol in fuels.
Well first off, I don't believe a word of that in regards to the temperatures. Where have you seen this and what substantiation do you have?
And secondly the issue was very rare here in the US as well. The problem was short trips (especially in cold weather climates) as well as excessively long oil change intervals. There has never been anything published that tied it to octane rating.
Lower octane increases piston, piston rings, cylinder walls temperature. Also ethanol exacerbates the problem. The sludge problem was limited to the USA where very low octane fuels like 87 (about 91-92 RON) are common. In Europe, the lowest octane is 95 RON (90-91 AKI) and the sludge problem is very-very rare. I doubt they allow more than 5% ethanol in fuels.
Well first off, I don't believe a word of that in regards to the temperatures. Where have you seen this and what substantiation do you have?
And secondly the issue was very rare here in the US as well. The problem was short trips (especially in cold weather climates) as well as excessively long oil change intervals. There has never been anything published that tied it to octane rating.
Originally Posted by RDY4WAR
Another factor is the spark plugs used with ethanol fuel. Ethanol absorbs a lot of heat so a hotter plug is necessary to keep it clean. A common mistake in the racing world is people will run E85 at .82 lambda and -9 or -10 NGK plugs trying to tune it like a gas engine, then they get fouled plugs, hard starts, and hesitation. Running them on -7 plugs and .70 lambda netted more power and cleaner burn. It's a highly oxygenated fuel so you can't treat it like gasoline.
IF this above is truly the case, then the tuners on the Fiesta Forums had better wake up, since they ALL, to a ONE, tell their customers that one step colder plugs are REQUISITE for all of their tunes, yes, even the E30 and E40 ones.
(But these apps/tunes are for open tracking/road race, or street use on factory 10.1:1 comp ratio engines running higher boost, NOT staging lane warm-up only, drag race use, so maybe that is the difference?
)
Another factor is the spark plugs used with ethanol fuel. Ethanol absorbs a lot of heat so a hotter plug is necessary to keep it clean. A common mistake in the racing world is people will run E85 at .82 lambda and -9 or -10 NGK plugs trying to tune it like a gas engine, then they get fouled plugs, hard starts, and hesitation. Running them on -7 plugs and .70 lambda netted more power and cleaner burn. It's a highly oxygenated fuel so you can't treat it like gasoline.
IF this above is truly the case, then the tuners on the Fiesta Forums had better wake up, since they ALL, to a ONE, tell their customers that one step colder plugs are REQUISITE for all of their tunes, yes, even the E30 and E40 ones.
(But these apps/tunes are for open tracking/road race, or street use on factory 10.1:1 comp ratio engines running higher boost, NOT staging lane warm-up only, drag race use, so maybe that is the difference?
Originally Posted by dailydriver
Originally Posted by RDY4WAR
Another factor is the spark plugs used with ethanol fuel. Ethanol absorbs a lot of heat so a hotter plug is necessary to keep it clean. A common mistake in the racing world is people will run E85 at .82 lambda and -9 or -10 NGK plugs trying to tune it like a gas engine, then they get fouled plugs, hard starts, and hesitation. Running them on -7 plugs and .70 lambda netted more power and cleaner burn. It's a highly oxygenated fuel so you can't treat it like gasoline.
IF this above is truly the case, then the tuners on the Fiesta Forums had better wake up, since they ALL, to a ONE, tell their customers that one step colder plugs are REQUISITE for all of their tunes, yes, even the E30 and E40 ones.
(But these apps/tunes are for open tracking/road race, or street use on factory 10.1:1 comp ratio engines running higher boost, NOT staging lane warm-up only, drag race use, so maybe that is the difference?
)
I had a lengthy discussion with one of the reputable (if not the most reputable) tuners in the FoST/FiST community about why they suggest that. He said the only reason they suggest that is because when people switch to E85, they also tend to turn up the boost, so they're just trying to CYA. In their competition race cars, they run 1-2 steps hotter than comparable with stock, but they know exactly what they're going to do with it. E85 is more forgiving than gasoline.
Originally Posted by RDY4WAR
Another factor is the spark plugs used with ethanol fuel. Ethanol absorbs a lot of heat so a hotter plug is necessary to keep it clean. A common mistake in the racing world is people will run E85 at .82 lambda and -9 or -10 NGK plugs trying to tune it like a gas engine, then they get fouled plugs, hard starts, and hesitation. Running them on -7 plugs and .70 lambda netted more power and cleaner burn. It's a highly oxygenated fuel so you can't treat it like gasoline.
IF this above is truly the case, then the tuners on the Fiesta Forums had better wake up, since they ALL, to a ONE, tell their customers that one step colder plugs are REQUISITE for all of their tunes, yes, even the E30 and E40 ones.
(But these apps/tunes are for open tracking/road race, or street use on factory 10.1:1 comp ratio engines running higher boost, NOT staging lane warm-up only, drag race use, so maybe that is the difference?
I had a lengthy discussion with one of the reputable (if not the most reputable) tuners in the FoST/FiST community about why they suggest that. He said the only reason they suggest that is because when people switch to E85, they also tend to turn up the boost, so they're just trying to CYA. In their competition race cars, they run 1-2 steps hotter than comparable with stock, but they know exactly what they're going to do with it. E85 is more forgiving than gasoline.
Originally Posted by Ded Mazai
Lower octane increases piston, piston rings, cylinder walls temperature. Also ethanol exacerbates the problem. The sludge problem was limited to the USA where very low octane fuels like 87 (about 91-92 RON) are common. In Europe, the lowest octane is 95 RON (90-91 AKI) and the sludge problem is very-very rare. I doubt they allow more than 5% ethanol in fuels.
Where did you dig this bovine from?
Lower octane increases piston, piston rings, cylinder walls temperature. Also ethanol exacerbates the problem. The sludge problem was limited to the USA where very low octane fuels like 87 (about 91-92 RON) are common. In Europe, the lowest octane is 95 RON (90-91 AKI) and the sludge problem is very-very rare. I doubt they allow more than 5% ethanol in fuels.
Where did you dig this bovine from?
I just filled up with midgrade today. In last 5500 miles I ran regular unleaded with average of 20.1 mpg in Grand Caravan. I have run midgrade in last car because of carbon but since this one is newer didn't see a need but with econ driving mode rpms are low and I know that higher octane allows engine to be more efficient as well as less pollution. I will keep a track record of fuel as I always have but don't expect any gain of mpg as I stated it is for efficiency. It is a flex fuel vehicle with manual stating any octane higher than 87 up to E85
Originally Posted by tiger862
I just filled up with midgrade today. In last 5500 miles I ran regular unleaded with average of 20.1 mpg in Grand Caravan. I have run midgrade in last car because of carbon but since this one is newer didn't see a need but with econ driving mode rpms are low and I know that higher octane allows engine to be more efficient as well as less pollution. I will keep a track record of fuel as I always have but don't expect any gain of mpg as I stated it is for efficiency. It is a flex fuel vehicle with manual stating any octane higher than 87 up to E85
Well here is update. Vehicle was smooth and had to look at tach to see rpms but thought it was like that before. No gain in fuel mileage so went back to regular and within s short period I heard rpms so definitely noisier but you get used to it quickly. I didn't notice any changes until I got off interstate in econ mode that the jerk when going on overpass from a stop was back. I filled up with midgrade again same results as vehicle likes it better although no improvement in fuel mileage as well as quieter when shifting. This was a 1500 mile run.
I just filled up with midgrade today. In last 5500 miles I ran regular unleaded with average of 20.1 mpg in Grand Caravan. I have run midgrade in last car because of carbon but since this one is newer didn't see a need but with econ driving mode rpms are low and I know that higher octane allows engine to be more efficient as well as less pollution. I will keep a track record of fuel as I always have but don't expect any gain of mpg as I stated it is for efficiency. It is a flex fuel vehicle with manual stating any octane higher than 87 up to E85
Well here is update. Vehicle was smooth and had to look at tach to see rpms but thought it was like that before. No gain in fuel mileage so went back to regular and within s short period I heard rpms so definitely noisier but you get used to it quickly. I didn't notice any changes until I got off interstate in econ mode that the jerk when going on overpass from a stop was back. I filled up with midgrade again same results as vehicle likes it better although no improvement in fuel mileage as well as quieter when shifting. This was a 1500 mile run.
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Originally Posted by racin4ds
Originally Posted by Tahoe4Life
Anything over 87 octane is a complete waste for most motorists. It is nothing more then a placebo effort that your vehicle has more power. I mistakenly put in 93 octane in my Tahoe while on a cross country trip. I got no more power and the exact same gas mileage as 87 octane. My buddy has 2015 Escalade with the 6.2. The Escalade runs perfectly on 87 octane for the past 90K miles.
So not true! Just because your hunk of GM junk doesn't have smart enough knock control and timing advance based on knock input and other variables doesn't mean MANY other cars on the road don't. I have used 89/91 octane in many vehicles that required the use of 87 and found much better performance backed up by a nice boost in mileage.
ANY of the newer, turbocharged cars on the road today can and will benefit from the use of high octane fuels, that is fact. Sure the manual says you can run 87 in it but that is making the knock controls reduce timing everywhere, ultimately causing lower MPG and poor performance.
My two Ford Fusions with the 1.5 GDI Turbo 10.1 Compression Ratio both get about 3 miles a gallon more with 93 octane fuel instead of the 87 octane that ford recommends. One is a 2016 other 2018.
Originally Posted by Tahoe4Life
Anything over 87 octane is a complete waste for most motorists. It is nothing more then a placebo effort that your vehicle has more power. I mistakenly put in 93 octane in my Tahoe while on a cross country trip. I got no more power and the exact same gas mileage as 87 octane. My buddy has 2015 Escalade with the 6.2. The Escalade runs perfectly on 87 octane for the past 90K miles.
So not true! Just because your hunk of GM junk doesn't have smart enough knock control and timing advance based on knock input and other variables doesn't mean MANY other cars on the road don't. I have used 89/91 octane in many vehicles that required the use of 87 and found much better performance backed up by a nice boost in mileage.
ANY of the newer, turbocharged cars on the road today can and will benefit from the use of high octane fuels, that is fact. Sure the manual says you can run 87 in it but that is making the knock controls reduce timing everywhere, ultimately causing lower MPG and poor performance.
My two Ford Fusions with the 1.5 GDI Turbo 10.1 Compression Ratio both get about 3 miles a gallon more with 93 octane fuel instead of the 87 octane that ford recommends. One is a 2016 other 2018.
Here, 87 octane is $2.49/gal and 93 is $3.19/gal. That's a 28% price increase. In order to break even, you need to use 28% less fuel. If you were getting 30 mpg before, you'd need to get 38.4 mpg after just to break even. Is that even possible with OEM progamming auto-adjustments?
I tuned my focus for maximum mpg with it as lean and timing advanced as it would go without detonation on 93 and saw a 5% difference at best, nowhere near 28%.
I tuned my focus for maximum mpg with it as lean and timing advanced as it would go without detonation on 93 and saw a 5% difference at best, nowhere near 28%.
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I run 89 octane cause it is a blend of regular and premium. You still get the extra cleaning of premium
Does make a difference in vehicles that are flex fuel vehicle.
Does make a difference in vehicles that are flex fuel vehicle.
I've been experimenting and my Silverado idles smoother on 89. The V8 to V4 and V4 to V8 transitions are also smoother on 89. I couldn't tell a difference between 89 and 91. The compression ratio is 11:1 on that L83, so I'm sure the higher octane helps some with that. There is no difference in fuel mileage at all though, just a smoother engine. I thought it was all in my head, so I started to experiment on my wife's 4Runner, and it makes no difference. It runs the same with 87, 89, and 91. Ironically, my truck gets better MPG than her 4Runner too!
Originally Posted by tdi jerry
Originally Posted by racin4ds
Originally Posted by Tahoe4Life
Anything over 87 octane is a complete waste for most motorists. It is nothing more then a placebo effort that your vehicle has more power. I mistakenly put in 93 octane in my Tahoe while on a cross country trip. I got no more power and the exact same gas mileage as 87 octane. My buddy has 2015 Escalade with the 6.2. The Escalade runs perfectly on 87 octane for the past 90K miles.
So not true! Just because your hunk of GM junk doesn't have smart enough knock control and timing advance based on knock input and other variables doesn't mean MANY other cars on the road don't. I have used 89/91 octane in many vehicles that required the use of 87 and found much better performance backed up by a nice boost in mileage.
ANY of the newer, turbocharged cars on the road today can and will benefit from the use of high octane fuels, that is fact. Sure the manual says you can run 87 in it but that is making the knock controls reduce timing everywhere, ultimately causing lower MPG and poor performance.
My two Ford Fusions with the 1.5 GDI Turbo 10.1 Compression Ratio both get about 3 miles a gallon more with 93 octane fuel instead of the 87 octane that ford recommends. One is a 2016 other 2018.
Same; I know my car well enough where I can tell the difference. I just came back from another roadtrip from IL to UT and the 85/87oct over in the mountains is straight garbage; the car is knocking so much that you can feel the computer pulling timing so much it ends up not letting you accelerate on an on-ramp.
Originally Posted by racin4ds
Originally Posted by Tahoe4Life
Anything over 87 octane is a complete waste for most motorists. It is nothing more then a placebo effort that your vehicle has more power. I mistakenly put in 93 octane in my Tahoe while on a cross country trip. I got no more power and the exact same gas mileage as 87 octane. My buddy has 2015 Escalade with the 6.2. The Escalade runs perfectly on 87 octane for the past 90K miles.
So not true! Just because your hunk of GM junk doesn't have smart enough knock control and timing advance based on knock input and other variables doesn't mean MANY other cars on the road don't. I have used 89/91 octane in many vehicles that required the use of 87 and found much better performance backed up by a nice boost in mileage.
ANY of the newer, turbocharged cars on the road today can and will benefit from the use of high octane fuels, that is fact. Sure the manual says you can run 87 in it but that is making the knock controls reduce timing everywhere, ultimately causing lower MPG and poor performance.
My two Ford Fusions with the 1.5 GDI Turbo 10.1 Compression Ratio both get about 3 miles a gallon more with 93 octane fuel instead of the 87 octane that ford recommends. One is a 2016 other 2018.
Same; I know my car well enough where I can tell the difference. I just came back from another roadtrip from IL to UT and the 85/87oct over in the mountains is straight garbage; the car is knocking so much that you can feel the computer pulling timing so much it ends up not letting you accelerate on an on-ramp.
Originally Posted by tdi jerry
Originally Posted by racin4ds
Originally Posted by Tahoe4Life
Anything over 87 octane is a complete waste for most motorists. It is nothing more then a placebo effort that your vehicle has more power. I mistakenly put in 93 octane in my Tahoe while on a cross country trip. I got no more power and the exact same gas mileage as 87 octane. My buddy has 2015 Escalade with the 6.2. The Escalade runs perfectly on 87 octane for the past 90K miles.
So not true! Just because your hunk of GM junk doesn't have smart enough knock control and timing advance based on knock input and other variables doesn't mean MANY other cars on the road don't. I have used 89/91 octane in many vehicles that required the use of 87 and found much better performance backed up by a nice boost in mileage.
ANY of the newer, turbocharged cars on the road today can and will benefit from the use of high octane fuels, that is fact. Sure the manual says you can run 87 in it but that is making the knock controls reduce timing everywhere, ultimately causing lower MPG and poor performance.
My two Ford Fusions with the 1.5 GDI Turbo 10.1 Compression Ratio both get about 3 miles a gallon more with 93 octane fuel instead of the 87 octane that ford recommends. One is a 2016 other 2018.
My parents never tried with the 1.5 Escape, but their 2.0 Escape definitely saw enough of an improvement in fuel mileage switching to 91 that it ended up being cheaper to run 91.
Originally Posted by racin4ds
Originally Posted by Tahoe4Life
Anything over 87 octane is a complete waste for most motorists. It is nothing more then a placebo effort that your vehicle has more power. I mistakenly put in 93 octane in my Tahoe while on a cross country trip. I got no more power and the exact same gas mileage as 87 octane. My buddy has 2015 Escalade with the 6.2. The Escalade runs perfectly on 87 octane for the past 90K miles.
So not true! Just because your hunk of GM junk doesn't have smart enough knock control and timing advance based on knock input and other variables doesn't mean MANY other cars on the road don't. I have used 89/91 octane in many vehicles that required the use of 87 and found much better performance backed up by a nice boost in mileage.
ANY of the newer, turbocharged cars on the road today can and will benefit from the use of high octane fuels, that is fact. Sure the manual says you can run 87 in it but that is making the knock controls reduce timing everywhere, ultimately causing lower MPG and poor performance.
My two Ford Fusions with the 1.5 GDI Turbo 10.1 Compression Ratio both get about 3 miles a gallon more with 93 octane fuel instead of the 87 octane that ford recommends. One is a 2016 other 2018.
My parents never tried with the 1.5 Escape, but their 2.0 Escape definitely saw enough of an improvement in fuel mileage switching to 91 that it ended up being cheaper to run 91.
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