Sc400 owners what grade fuel do you use?
03-30-11, 08:05 AM
#16
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89oct with 10% ethanol. Here, you have no choice but to use ethanol so that's what it is. And no difference in 89 and 91 on my car other than cost. Never run 87 cuz it costs more than 89 for some reason.
03-30-11, 08:08 AM
#17
1JZ Single SC400
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I have 92 and its get only premium.. I have never had any knock or valves pinging. Premium here in Bama on post is $3.59.. Still high for us.. But I would hate to live out west.
03-30-11, 10:06 AM
#18
It's not about affordability, it's about wasting cash man. And that's an idiotic and arrogant attitude when most of these SCs cost less than a honda civic haha.
So first off, premium gas has a higher heat of combustion and THAT is the primary reason for higher octane and why it resists pre-ignition. Some of the additives do make it more efficient, but the difference in negligible. The price difference however is very real.
I put on about 15,000 miles per year which after some basic math is about 900 gallons of gas. Difference in my area is about $.35 between regular and premium and about $.25 between 89 and 91. Even just switching to 89 will save over $200 per year. Why throw away $200 when it literally makes NO difference in the performance and reliability of your engine?
So first off, premium gas has a higher heat of combustion and THAT is the primary reason for higher octane and why it resists pre-ignition. Some of the additives do make it more efficient, but the difference in negligible. The price difference however is very real.
I put on about 15,000 miles per year which after some basic math is about 900 gallons of gas. Difference in my area is about $.35 between regular and premium and about $.25 between 89 and 91. Even just switching to 89 will save over $200 per year. Why throw away $200 when it literally makes NO difference in the performance and reliability of your engine?
03-30-11, 02:51 PM
#21
I guess my question was worded wrong, It should have read... Why do sc400 owners feel they need 93 oct fuel?With that being said I once knew a guy who had a corsica and would fill it with nothing but 93 fuel and he swore he could feel the power increase
Fml!
03-30-11, 03:17 PM
#22
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I use what’s recommended in the Lexus Owners manual which is 91+ premium, if Lexus recommended a lower grade then i would use that. But they don’t so 91+ is best for this car. If you want to run lower grade in your car then go right ahead the best to you
03-30-11, 03:53 PM
#23
About gasoline here is some food for thought, top of the line engine oil from 1995 couldn't even be sold as 99 cent a quart no-name oil today. Oil technology has progressed to the point that todays product is not even comparable to its former incarnations, its just so much better. I cannot imagine that there has been no improvement in the quality of gasoline, and I know for a fact that there has been. Additive quality has improved greatly and EPA regs have mandated removal of particulate contaminates that increased emissions, with a side benefit of increasing detonation resistance. We aren't driving around on our grandfathers gasoline.
03-30-11, 04:11 PM
#24
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This is a serious question for the non vvti sc400 owners with a stock 1uzfe.
Since there is a 30 cents differebce between 87 and 93 the savings will add up pretty fast if I could long term getaway with crap gas.
In my is300 I could run cheap gas but mileage was worse due to ping or knock being picked up via the knock sensor and of course pulling timing but being the 1st gen 1uzfe is a non vvti engine and although a 10:1 compression ratio I would venture to guess I could get away with 89 oct fuel with out knock.
I hate to even ask this but 80.00 per week in gas is getting old and fast!
Since there is a 30 cents differebce between 87 and 93 the savings will add up pretty fast if I could long term getaway with crap gas.
In my is300 I could run cheap gas but mileage was worse due to ping or knock being picked up via the knock sensor and of course pulling timing but being the 1st gen 1uzfe is a non vvti engine and although a 10:1 compression ratio I would venture to guess I could get away with 89 oct fuel with out knock.
I hate to even ask this but 80.00 per week in gas is getting old and fast!
03-30-11, 05:04 PM
#25
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1992 Lexus Owners Manual for the SC300 and SC400 state:
Your call
Octane Rating
Select premium unleaded gasoline with Research Octane Number of 96 (Octane Rating 91) or higher. However gasoline with an octane number as low as 91 may be used if premium unleaded gasoline cannot be obtained.
Use of unleaded fuel with an octane number or rating lower than stated above will cause persistent heavy knocking. If severe, this will lead to engine damage.
Select premium unleaded gasoline with Research Octane Number of 96 (Octane Rating 91) or higher. However gasoline with an octane number as low as 91 may be used if premium unleaded gasoline cannot be obtained.
Use of unleaded fuel with an octane number or rating lower than stated above will cause persistent heavy knocking. If severe, this will lead to engine damage.
03-30-11, 05:39 PM
#26
Yes, that was for gas twenty years ago. The oil companies have made huge leaps in refining processes that have increased the quality of even lower octane fuels. When I bought my car in January I fully intended to always run 93 in it, then gas went up a dollar a gallon and after some testing all is well so 87 it is.
03-30-11, 05:43 PM
#27
1992 Lexus Owners Manual for the SC300 and SC400 state:
Your call
Octane Rating
Select premium unleaded gasoline with Research Octane Number of 96 (Octane Rating 91) or higher. However gasoline with an octane number as low as 91 may be used if premium unleaded gasoline cannot be obtained.
Use of unleaded fuel with an octane number or rating lower than stated above will cause persistent heavy knocking. If severe, this will lead to engine damage.
Select premium unleaded gasoline with Research Octane Number of 96 (Octane Rating 91) or higher. However gasoline with an octane number as low as 91 may be used if premium unleaded gasoline cannot be obtained.
Use of unleaded fuel with an octane number or rating lower than stated above will cause persistent heavy knocking. If severe, this will lead to engine damage.
motivation enough for me to use premium...
I don't drive the sc as a dd (part because it's broken, atm, part because my dd gets 50% better economy), but when I do, it's premium all the way.
Last edited by BenStoked; 03-30-11 at 05:50 PM.
03-30-11, 06:31 PM
#29
i get about 20-30 miles more per tank using 93 vs 87 tried both , really dosent matter i did the math a while a go and for me running 93 is actually cheaper not that a 15 dollar/month is going to make a difference for me or should for anyone to even worry about.
