Merged premium fuel threads - is higher than 87 Octane needed or useful?
02-18-20, 09:56 PM
#46
Instructor
Research Octane is not the same thing as “Octane number” aka “Anti-knock rating” which is what we see posted on the pumps. A pump with “87 Octane” in USA and Canada is putting out a fuel with a 91 “Research Octane”. From Wikipedia, “In most countries in Europe (also in Australia, Pakistan and New Zealand) the "headline" octane rating shown on the pump is the RON, but in Canada, the United States, Brazil, and some other countries, the headline number is the simple mean or average of the RON and the MON, called the Anti-Knock Index (AKI), and often written on pumps as (R+M)/2
Because of the 8 to 12 octane number difference between RON and MON noted above, the AKI shown in Canada and the United States is 4 to 6 octane numbers lower than elsewhere in the world for the same fuel. This difference between RON and MON is known as the fuel's Sensitivity,[5] and is not typically published for those countries that use the Anti-Knock Index labelling system.”
We refer to 87 Octane as “Regular” and that is what the 2020 manual calls for as a minimum.
I don’t know why you say that only marine gas is “ethanol-free” .... certainly none of the gas I buy has ethanol in it as it (and it’s percentage) must be posted on the pump.
Because of the 8 to 12 octane number difference between RON and MON noted above, the AKI shown in Canada and the United States is 4 to 6 octane numbers lower than elsewhere in the world for the same fuel. This difference between RON and MON is known as the fuel's Sensitivity,[5] and is not typically published for those countries that use the Anti-Knock Index labelling system.”
We refer to 87 Octane as “Regular” and that is what the 2020 manual calls for as a minimum.
I don’t know why you say that only marine gas is “ethanol-free” .... certainly none of the gas I buy has ethanol in it as it (and it’s percentage) must be posted on the pump.
Last edited by Tootsall; 02-18-20 at 10:02 PM.
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kalel2127 (02-19-20)
02-19-20, 05:35 AM
#47
Fuel Fuel type Unleaded gasoline only
Octane Rating 87 (Research Octane Number 91) or higher
Fuel tank capacity (Reference) 16.0 gal. (60.6 L, 13.3 Imp.gal.)
02-19-20, 05:55 AM
#48
Lead Lap
I'm not sure where you think that you saw that the 2020 ES requires premium 91 octane fuel.
For all Generation 6 and Generation 7 ES (model years 2013-2020, the recommended fuel is regular/87 octane rating fuel.
For even Generation 4 and Generation 5 ES cars, while the "recommended" fuel was premium/91 octane fuel, Lexus stated that the premium fuel was "recommended", not "required". For those Generation 4 and Generation 5 ES cars, there may have been a slight loss of horsepower and/or fuel economy with regular fuel, but the variable valve timing of the engines was capable of adjusting to and performing fine with 87 octane fuel.
With a Generation 6 or Generation 7 ES, using premium fuel will not improve performance or fuel economy. It will only drain your wallet faster.
I have not seen any Lexus document, including brochures, manuals, or other Lexus website information that indicates that the 2020 ES requires premium fuel or that premium fuel is even recommended.
https://lexus2.custhelp.com/app/answ...xus-vehicle%3F
For all Generation 6 and Generation 7 ES (model years 2013-2020, the recommended fuel is regular/87 octane rating fuel.
For even Generation 4 and Generation 5 ES cars, while the "recommended" fuel was premium/91 octane fuel, Lexus stated that the premium fuel was "recommended", not "required". For those Generation 4 and Generation 5 ES cars, there may have been a slight loss of horsepower and/or fuel economy with regular fuel, but the variable valve timing of the engines was capable of adjusting to and performing fine with 87 octane fuel.
With a Generation 6 or Generation 7 ES, using premium fuel will not improve performance or fuel economy. It will only drain your wallet faster.
I have not seen any Lexus document, including brochures, manuals, or other Lexus website information that indicates that the 2020 ES requires premium fuel or that premium fuel is even recommended.
https://lexus2.custhelp.com/app/answ...xus-vehicle%3F
Last edited by lesz; 02-19-20 at 12:06 PM.
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02-19-20, 04:52 PM
#49
Driver School Candidate
Possibly in Alberta you have more selection than we do. I'm not aware of any gas around us that is ethanol free. I know marine gas is but I personally don't know of any car gas that is. Maybe I just don't see it. I go to the same gas bar every time I fill and they only sell E10 and diesel. That's all.
02-19-20, 05:27 PM
#50
Possibly in Alberta you have more selection than we do. I'm not aware of any gas around us that is ethanol free. I know marine gas is but I personally don't know of any car gas that is. Maybe I just don't see it. I go to the same gas bar every time I fill and they only sell E10 and diesel. That's all.
Around me most all the stations have signs that the gas may contain up to 10% ethanol. There is no guarantee the stations that do not have the sign are ethical free either, as in Ohio it is no longer required for stations to post it. The laws about this do vary by state.
02-19-20, 09:25 PM
#51
Instructor
Possibly in Alberta you have more selection than we do. I'm not aware of any gas around us that is ethanol free. I know marine gas is but I personally don't know of any car gas that is. Maybe I just don't see it. I go to the same gas bar every time I fill and they only sell E10 and diesel. That's all.
Seems counter-intuitive to me to give up food producing land over to fuel production when you have to burn more volume to go the same distance! (But that’s a topic for another day
)
Last edited by Tootsall; 02-19-20 at 09:39 PM.
02-21-20, 03:26 PM
#53
Lead Lap
This thread, along with the other half dozen asking the same questions, is useless. The cars, ES 350 and 300H, use regular unleaded gas. Available almost anywhere in America and Canada. No premium, no marine fuel, no jet fuel, no Panther ****. Final, done, READ THE MANUAL!!
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02-24-20, 12:06 AM
#54
On a trip to Oregon, I found a chain of local gas stations the offered ethanol free gasoline so I tried a couple of tanks. Engine power and smoothness were unchanged but the mileage improved about 10%. The extra cost of the "pure" gasoline was more, however, than the improved mileage was worth.
01-02-21, 01:42 AM
#56
Premium Fuel
Any of you folks running anything higher than 87? Around here, Sunoco offers 89 and 91. From everything I have read, running octane any higher than engine is tuned to accept is just a waste of money. Was thinking about trying 89 or 91 for kicks and giggles...what are you guys doing? Thx.
01-02-21, 05:50 AM
#58
Lead Lap
Your car's engine was designed by engineers to run optimally on 87 octane fuel. My car does and I'm assuming yours does too. So why spend more money for gas than needed? 
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01-02-21, 06:11 AM
#59
Pole Position
We want to treat our vehicles the best and if putting premium gas does that for you by all means go for it. Before making a decision I always research and see what the experts recommend. Have used 87 octane in our 2015 RX450h and currently 2017 which both premium is recommended. Experimenting with the other two levels, I have noticed zero difference in gas mileage or performance. I have used 87 in cars that have required premium for over a million miles and have not had one problem.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
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bc6152 (01-02-21)
01-02-21, 08:13 AM
#60
We want to treat our vehicles the best and if putting premium gas does that for you by all means go for it. Before making a decision I always research and see what the experts recommend. Have used 87 octane in our 2015 RX450h and currently 2017 which both premium is recommended. Experimenting with the other two levels, I have noticed zero difference in gas mileage or performance. I have used 87 in cars that have required premium for over a million miles and have not had one problem.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4
From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.
Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.
I listened to those guys for many years and found them informative, but it was primarily an entertainment show and I often questioned their conclusions and recommendations. I wonder if their thinking on this subject is somewhat out of date.