Fuel discussions/questions - Octane Regular or Premium (merged threads)
06-22-23, 09:25 PM
#511
Intermediate
I'll just keep using what's recommended, if it was an older car with 200k+ miles I might go cheap and don't care. However, we own a few older BMW models, older than 20 years, they require premium and that's what they get. It is my personal choice and don't even consider using lower grade, low quality gas. I'll make sure I let you know when my fuel pump melts away from using premium.
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Hehena (06-23-23)
06-23-23, 07:21 AM
#512
Pole Position
Ok, I think we can come to the closure on this. I can say that I know for a fact that vegetable oil is better for lubrication in the GX but cannot explain why because you would need to learn a lot and I cannot point you to any credible study or report that would support it. But I know it and that's it.
I'll just keep using what's recommended, if it was an older car with 200k+ miles I might go cheap and don't care. However, we own a few older BMW models, older than 20 years, they require premium and that's what they get. It is my personal choice and don't even consider using lower grade, low quality gas. I'll make sure I let you know when my fuel pump melts away from using premium.
I'll just keep using what's recommended, if it was an older car with 200k+ miles I might go cheap and don't care. However, we own a few older BMW models, older than 20 years, they require premium and that's what they get. It is my personal choice and don't even consider using lower grade, low quality gas. I'll make sure I let you know when my fuel pump melts away from using premium.
06-23-23, 07:34 AM
#513
Intermediate
Thank You, this statement brought back such great memories of racing back in the 1970's when Castrol R was the chosen engine oil. It was a plant based oil and I still remember the unique smell in the pits and on the track.
Last edited by IanG; 06-23-23 at 08:16 AM.
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NewB2Lexus (06-23-23)
06-23-23, 07:36 AM
#514
Intermediate
Agree ... but using "lower grade" and "low quality" in the same sentence confuses the subject ... non-Top-Tier vs. Top-Tier ... yes, there is a quality difference. Lower octane is not "low quality" ... gas is gas ... all has the same energy value ... the only difference is any concern over detonation. Agree ... older classic cars do not have knock sensors ... so given they have a fixed timing advance curve ... yes, octane is an important consideration ... and yes, I use 93 in all of my classic cars and motorcycles ... and use non-ethanol gas as well ... now how about ethanol as a continuing subject ?
Last edited by NewB2Lexus; 06-23-23 at 07:40 AM.
06-23-23, 07:56 AM
#515
Pole Position
Always loved that Castrol R smell on my clothes after a day of 2-Stroke riding.
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IanG (06-23-23)
06-23-23, 08:33 AM
#516
Everyone could just datalog KCLV(knock correction learned value) and KF(Knock Feedback) and see what the different fuels do for them.
I havent bothered to experiement with my GX all that much, but on my F150 Ecoboost I gain 2-3* of timing for every 2 octane I put in. I have played with 89, 91, 94 and 96 octane. Even on 96 octane I do not max out the available timing adjustment built into the PCM and could probably run 98 and still see an improvement.
I havent bothered to experiement with my GX all that much, but on my F150 Ecoboost I gain 2-3* of timing for every 2 octane I put in. I have played with 89, 91, 94 and 96 octane. Even on 96 octane I do not max out the available timing adjustment built into the PCM and could probably run 98 and still see an improvement.
Last edited by skrypj; 06-23-23 at 08:37 AM.
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John00 (06-23-23)
06-23-23, 09:46 AM
#517
Pole Position
Everyone could just datalog KCLV(knock correction learned value) and KF(Knock Feedback) and see what the different fuels do for them.
I havent bothered to experiement with my GX all that much, but on my F150 Ecoboost I gain 2-3* of timing for every 2 octane I put in. I have played with 89, 91, 94 and 96 octane. Even on 96 octane I do not max out the available timing adjustment built into the PCM and could probably run 98 and still see an improvement.
I havent bothered to experiement with my GX all that much, but on my F150 Ecoboost I gain 2-3* of timing for every 2 octane I put in. I have played with 89, 91, 94 and 96 octane. Even on 96 octane I do not max out the available timing adjustment built into the PCM and could probably run 98 and still see an improvement.
06-23-23, 10:37 AM
#518
I had heard(and seen in the tune on HPTuners) that the 5.7L in the Tundra is limited to a maximum KCLV of 19, which I believe could be achievable on 87 or 89 octane. That may be the difference between the Lexus and Toyota variants of the 1UR and 3UR, they might simply limit the maximum timing advance on the Toyotas so the benefit of higher octane simply isnt as obvious. VFTuner does not have the KCLV limit available for my GX tune so I am not entire sure what the upper limit is, but I have seen as high as 23 or 24 briefly on 91. I thought about trying 94 octane(91+Boostane) just to see what it did.
I would only bother to run 94 octane if I was towing and wanted the little bit of extra grunt. For me, 91 is an easy choice because the cost difference vs 85 octane(in the Rockies so lower octanes at the pump) is only like 30-40 cents. I woudlnt run 85 anyways, so I am only paying 15-20 cents more than 89 for 91. At ~$4.20 a gallon, the difference is pretty small for me.
Last edited by skrypj; 06-23-23 at 10:44 AM.
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NewB2Lexus (06-23-23)
06-23-23, 12:46 PM
#519
Ok, I think we can come to the closure on this. I can say that I know for a fact that vegetable oil is better for lubrication in the GX but cannot explain why because you would need to learn a lot and I cannot point you to any credible study or report that would support it. But I know it and that's it.
I'll just keep using what's recommended, if it was an older car with 200k+ miles I might go cheap and don't care. However, we own a few older BMW models, older than 20 years, they require premium and that's what they get. It is my personal choice and don't even consider using lower grade, low quality gas. I'll make sure I let you know when my fuel pump melts away from using premium.
I'll just keep using what's recommended, if it was an older car with 200k+ miles I might go cheap and don't care. However, we own a few older BMW models, older than 20 years, they require premium and that's what they get. It is my personal choice and don't even consider using lower grade, low quality gas. I'll make sure I let you know when my fuel pump melts away from using premium.
yeah you can say you know for a fact, but that doesnt make you correct. in fact vegetable oil is not a better lubricant. i already provided the information that applies to the gx
Last edited by DaveGS4; 06-23-23 at 12:59 PM. Reason: Personal comments not needed
06-23-23, 12:51 PM
#520
we do have the test data for hp vs gas type. also have data for different polymers vs the same. issue is we cant go around sharing the data. this is why you only see some published studies usually as part of some school research paper. all mfgs have this. there are even standard test procedures for this.
12-01-23, 08:25 AM
#521
Premium or Regular
OK- word is 87 is fine, but no conclusive proof. What's the story ? I have a brand new GX, still has tank from the dealer. What do I do? Manual says premium, owners (some) say non-sense. I appreciate some advice - - noting I'm inclined to just follow the manual.
12-01-23, 08:28 AM
#522
Who would you believe, Lexus or some random strangers? Your car was tuned to run on premium and sure, the ecu will compensate and run on regular but are you that cheap?
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IanG (12-01-23)
12-01-23, 08:58 AM
#523
We put premium, the yearly cost saving based on our miles is not significant to justify using regular.
But each to his/hers own.
But each to his/hers own.
12-01-23, 09:10 AM
#524