Ownership Experience - 200t Premium vs Regular Fuel
Racer
Joined: Apr 2015
Posts: 1,723
Likes: 810
From: Ontario
@corradoMR2, thanks that was the answer I was looking for. I just put in 94 this week and same thing.. Felt slightly more, but not sure if it's worth the extra few cents per litre. Thanks!
Rookie
Joined: Sep 2013
Posts: 46
Likes: 11
From: Ontario
Wrong, timing is pulled as result of knocking being sensed by the knock sensors.
Lower octane fuel will increase likely hood of detonation, which in turn will increase knocking, to be detected by the knock sensors, and the ECU will then pull back timing to reduce or eliminate the knock. Once that timing is established, the engine will run happily, aside from the side effects of reduced performance.
The concern comes from the fact that the ECU always attempts to get the most optimal timing (based on fuel tables for 91 octane) by advancing timing, sensing the knock and pulling it back. That cycle is repeated over and over again, and in ideal scenario, the knock are few and far in between. What really happens is that aggressive drivers push the engine hard with sudden acceleration, and the knock frequency increases and volume increases before the ECU pulls back timing, thus leading to slow but increasingly steady damage. This is why you will hear of people never having issues using lower octane fuel, because they don't push their engine hard enough for knocking to be an issue, where as others have issues since they push their engines to the knock level and that can happen even with the right fuel if running the engine at redline consistently.
If
Lower octane fuel will increase likely hood of detonation, which in turn will increase knocking, to be detected by the knock sensors, and the ECU will then pull back timing to reduce or eliminate the knock. Once that timing is established, the engine will run happily, aside from the side effects of reduced performance.
The concern comes from the fact that the ECU always attempts to get the most optimal timing (based on fuel tables for 91 octane) by advancing timing, sensing the knock and pulling it back. That cycle is repeated over and over again, and in ideal scenario, the knock are few and far in between. What really happens is that aggressive drivers push the engine hard with sudden acceleration, and the knock frequency increases and volume increases before the ECU pulls back timing, thus leading to slow but increasingly steady damage. This is why you will hear of people never having issues using lower octane fuel, because they don't push their engine hard enough for knocking to be an issue, where as others have issues since they push their engines to the knock level and that can happen even with the right fuel if running the engine at redline consistently.
If
The pursuit of F
Joined: Jul 2006
Posts: 8,296
Likes: 303
From: Toronto, Canada
Lexus Test Driver
Joined: Apr 2008
Posts: 1,363
Likes: 2
From: Ontario
In general a boosted engine is more likely to knock due to the boost. I would stick with premium on the NX
Rookie
Joined: Sep 2013
Posts: 46
Likes: 11
From: Ontario
I doubt my wife will bother with that strategy to save some $, haha.
Got it. Thanks My0gr81.
The pursuit of F
Joined: Jul 2006
Posts: 8,296
Likes: 303
From: Toronto, Canada
. In any case, I feel no difference in performance from "my own blending" vs 91 directly from the pump not just for the NX, but IS and past cars. In warmer months, I take the extra minute to do two transactions at the pump as it saves a few dollars every time, but in the winter I pump 91 directly as I prefer not to freeze my rear! 
Last edited by corradoMR2; May 3, 2015 at 06:39 AM.
Driver
Joined: May 2014
Posts: 112
Likes: 1
From: VA
Articles publicly available show that 89 for example is blended from 87 and 91. I wonder if the select Petro Canada stations with 94 have 91 actually blended by 87 and 94 . In any case, I feel no difference in performance from "my own blending" vs 91 directly from the pump not just for the NX, but IS and past cars. In warmer months, I take the extra minute to do two transactions at the pump as it saves a few dollars every time, but in the winter I pump 91 directly as I prefer not to freeze my rear!
. In any case, I feel no difference in performance from "my own blending" vs 91 directly from the pump not just for the NX, but IS and past cars. In warmer months, I take the extra minute to do two transactions at the pump as it saves a few dollars every time, but in the winter I pump 91 directly as I prefer not to freeze my rear! 
Pole Position
Joined: Apr 2012
Posts: 2,243
Likes: 88
From: Texas
My dad owns a gas station as well and we only order regular and premium. Mid grade is blended by the pumps. If im not mistaken its 30% premium and 70% regular when blended for mid grade.
Driver
Joined: Aug 2015
Posts: 170
Likes: 1
From: CA
Pole Position
Joined: Apr 2014
Posts: 213
Likes: 1
From: NJ
what is interesting is the stations by me typically have 3 grades (87, 89, and 93). Some will have 92 instead of 93 in order to save a few cents a gallon. Do any cars actually require 89?
When traveling in Hawaii I saw most stations with 92 instead of 93 for the highest grade.
And some Sunoco stations will have 4 grades with 97, 89, 91, and 93.
When traveling in Hawaii I saw most stations with 92 instead of 93 for the highest grade.
And some Sunoco stations will have 4 grades with 97, 89, 91, and 93.
Pole Position
Joined: Jul 2015
Posts: 340
Likes: 28
From: Texas
Since my car has a "Premium Fuel Required" sticker on the refuel door and says the same thing in the OM, I will use premium fuel in it. The sales person said that the dealership only stocks 87 octane fuel and that's what they use in all the Lexus vehicles they sell. If that's true, my car had 87 octane for the first 4550 miles as it was a dealer demo.
Lexus Test Driver
Joined: May 2011
Posts: 1,492
Likes: 12
From: PA
92 will still meet the requirement of premium fuel. However, in the even that you are tuned to 93, and only 91 or 92 are available (which is the case for a 2013 GT-R), you can always fill the tank, and then put in an octane booster. That will usually put you within tolerance, however, this is a debated topic.
My Camaro is tuned for 93, and if I go to 91, you can feel it in the butt dyno and the car won't pull as hard. I'll just get an octane booster or put a gallon of 100 in to balance it out.
My Camaro is tuned for 93, and if I go to 91, you can feel it in the butt dyno and the car won't pull as hard. I'll just get an octane booster or put a gallon of 100 in to balance it out.
The pursuit of F
Joined: Jul 2006
Posts: 8,296
Likes: 303
From: Toronto, Canada
92 will still meet the requirement of premium fuel. However, in the even that you are tuned to 93, and only 91 or 92 are available (which is the case for a 2013 GT-R), you can always fill the tank, and then put in an octane booster. That will usually put you within tolerance, however, this is a debated topic.
My Camaro is tuned for 93, and if I go to 91, you can feel it in the butt dyno and the car won't pull as hard. I'll just get an octane booster or put a gallon of 100 in to balance it out.
My Camaro is tuned for 93, and if I go to 91, you can feel it in the butt dyno and the car won't pull as hard. I'll just get an octane booster or put a gallon of 100 in to balance it out.
Driver
Joined: Feb 2012
Posts: 102
Likes: 0
From: HI
I have a 2010 Prius, of course it is non turbo. I have used 87 octane for most of the past 5 years and almost 90,000 miles. I put in Octane booster every 5000 or so miles.
But during the summer when the temp averages around 90 degrees F, I would hear knocking under hard acceleration - which in itself is an Oxymoron. It only happens when the weather is very hot and the car is struggling to accelerate. So I fill up with 92 octane for 1 tank, then the knocking goes away. When the weather becomes cooler, which is low 80s, I go back to 87, no problem.
Its been stated here many time that turbo cars should use the higher octane fuel to prevent detonation of the engine.
I ordered the hybrid NX300, I intend to do the same as the prius. Use 87 primarily then go to 92 if needed. If I had the 200T, with the higher compression ratio when the turbo kicks in, I would use 92 and above only.
But during the summer when the temp averages around 90 degrees F, I would hear knocking under hard acceleration - which in itself is an Oxymoron. It only happens when the weather is very hot and the car is struggling to accelerate. So I fill up with 92 octane for 1 tank, then the knocking goes away. When the weather becomes cooler, which is low 80s, I go back to 87, no problem.
Its been stated here many time that turbo cars should use the higher octane fuel to prevent detonation of the engine.
I ordered the hybrid NX300, I intend to do the same as the prius. Use 87 primarily then go to 92 if needed. If I had the 200T, with the higher compression ratio when the turbo kicks in, I would use 92 and above only.
Lexus Test Driver
Joined: May 2011
Posts: 1,492
Likes: 12
From: PA
I have a 2010 Prius, of course it is non turbo. I have used 87 octane for most of the past 5 years and almost 90,000 miles. I put in Octane booster every 5000 or so miles.
But during the summer when the temp averages around 90 degrees F, I would hear knocking under hard acceleration - which in itself is an Oxymoron. It only happens when the weather is very hot and the car is struggling to accelerate. So I fill up with 92 octane for 1 tank, then the knocking goes away. When the weather becomes cooler, which is low 80s, I go back to 87, no problem.
Its been stated here many time that turbo cars should use the higher octane fuel to prevent detonation of the engine.
I ordered the hybrid NX300, I intend to do the same as the prius. Use 87 primarily then go to 92 if needed. If I had the 200T, with the higher compression ratio when the turbo kicks in, I would use 92 and above only.
But during the summer when the temp averages around 90 degrees F, I would hear knocking under hard acceleration - which in itself is an Oxymoron. It only happens when the weather is very hot and the car is struggling to accelerate. So I fill up with 92 octane for 1 tank, then the knocking goes away. When the weather becomes cooler, which is low 80s, I go back to 87, no problem.
Its been stated here many time that turbo cars should use the higher octane fuel to prevent detonation of the engine.
I ordered the hybrid NX300, I intend to do the same as the prius. Use 87 primarily then go to 92 if needed. If I had the 200T, with the higher compression ratio when the turbo kicks in, I would use 92 and above only.