Should you run premium fuel? Yes and no, explained.
03-14-08, 07:30 AM
#46
Driver School Candidate
So, based on his explaination, can too much octane also throw-off the timing? Is 93 too much?...should I stick with 91? I don't care about the price difference, I just want what is best for the car.
03-14-08, 11:04 AM
#49
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i think that on a car you feel the hit of better octane a bit less, and this leeds people to believe that its "all the same". the ls4 has a performance V8 and should be given the best gas to keep it in good condition. technically any car can be re-timed to run at a lower octane, but higher octanes then have reverse affects. i say run the higher octane- it does make a difference.
03-14-08, 11:21 AM
#50
Lexus Champion
Thread Starter
actually, super high octane won't do a thing. run 98 or 110 in our cars and it will run exactly the same as 93. the extra resistance to knock afforded by the race fuel means nothing in our relatively low compression engines. only on super high compression race engines or turbo/supercharged engines would 98 + provide more of a benefit over 93. for example, one could run more boost on 110 than 93, while still having the same amount of timing and fuel delivery. thus, you'll make more power.
03-14-08, 02:17 PM
#51
Agreed -- Anything higher than 91-93 is a waste of money. Our engines in 90-94 ran I believe 10.1 : 1 compression ratios at 256hp. While not crazy 'high' it isn't a low compression engine in contrast to other V8's of the time period. The chamber size and bore is much larger in this engine compared to , say, a 2.8liter, or 3 liter.
In 95 they made some slight modifications to the engine lighter pistons and rods.. which increased compression to 10.4/1 -- Bumped horsepower by 5.. (261base) -- This was the same in 95-96 models.
Which always makes me grin when people talk about how their 95 or 96 is 'faster' than the first gen.. There is no noticeable difference in power from 90-96.
In 97 further modifcations were made, mainly the Variable valve timing , slighting increase the CR to 10.5 -- But power output jumped to ~290bhp. There is a slight noticeable increase in feel from the 90-96 to the 97. Even at 30 more horsepower the 97 doesn't "smoke" any of the predecestrial LS 400's.
So in my opinion,.. if you run a 90-94 with 10.1 CR,.. 91 is all you need for 100% optimum function.
in a 95-96 , 91 should be just fine as well. 97+ models would probably benefit slightly from 93 octane.. but 91 , again, will do just fine.. and I would put money that on a Dyno no noticeable HP/Torque gain could be measured from 91 to 93,.. Or efficiency. In fact the opposite could be true on efficiency, but still so slight it is negligable.
People who think running 93 or 95,96,97,98,99,100-110+ octane is better, makes their engine faster, and so on -- In the 1UZ engines simply do not have a clue about how the engines operate. It is that simple.
I'm not pointing anyone out, or trying to make anyone feel bad, but people should be informed on what they are buying. Purchase the premium 93 all day long,.. I wouldn't smirk at anyone for that,.. I do it. But putting in octane booster, or trying to go beyond that -- Is a complete waste of money.. any effects you experience are placebo. (In the 1UZ).
I would smile if someone was adamant and trying to impose that I simply HAD to put 93 in my 1994 LS 400 when I picked up the 91 grade fuel nozzle.
As has been pointed out, and is quite obvious due to engine design.. The cars will run on anything from 87-93 (or higher) -- 87 won't damage the engine,.. the engine is designed to reduce itself depending on fuel quality. All I am saying is 91 is all the octane needed for 100% efficency, even in the 2008 models.
People will argue this fact all day long, but I will still stand behind it. =)
In 95 they made some slight modifications to the engine lighter pistons and rods.. which increased compression to 10.4/1 -- Bumped horsepower by 5.. (261base) -- This was the same in 95-96 models.
Which always makes me grin when people talk about how their 95 or 96 is 'faster' than the first gen.. There is no noticeable difference in power from 90-96.
In 97 further modifcations were made, mainly the Variable valve timing , slighting increase the CR to 10.5 -- But power output jumped to ~290bhp. There is a slight noticeable increase in feel from the 90-96 to the 97. Even at 30 more horsepower the 97 doesn't "smoke" any of the predecestrial LS 400's.
So in my opinion,.. if you run a 90-94 with 10.1 CR,.. 91 is all you need for 100% optimum function.
in a 95-96 , 91 should be just fine as well. 97+ models would probably benefit slightly from 93 octane.. but 91 , again, will do just fine.. and I would put money that on a Dyno no noticeable HP/Torque gain could be measured from 91 to 93,.. Or efficiency. In fact the opposite could be true on efficiency, but still so slight it is negligable.
People who think running 93 or 95,96,97,98,99,100-110+ octane is better, makes their engine faster, and so on -- In the 1UZ engines simply do not have a clue about how the engines operate. It is that simple.
I'm not pointing anyone out, or trying to make anyone feel bad, but people should be informed on what they are buying. Purchase the premium 93 all day long,.. I wouldn't smirk at anyone for that,.. I do it. But putting in octane booster, or trying to go beyond that -- Is a complete waste of money.. any effects you experience are placebo. (In the 1UZ).
I would smile if someone was adamant and trying to impose that I simply HAD to put 93 in my 1994 LS 400 when I picked up the 91 grade fuel nozzle.
As has been pointed out, and is quite obvious due to engine design.. The cars will run on anything from 87-93 (or higher) -- 87 won't damage the engine,.. the engine is designed to reduce itself depending on fuel quality. All I am saying is 91 is all the octane needed for 100% efficency, even in the 2008 models.
People will argue this fact all day long, but I will still stand behind it. =)
03-14-08, 03:08 PM
#52
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Agreed -- Anything higher than 91-93 is a waste of money. Our engines in 90-94 ran I believe 10.1 : 1 compression ratios at 256hp. While not crazy 'high' it isn't a low compression engine in contrast to other V8's of the time period. The chamber size and bore is much larger in this engine compared to , say, a 2.8liter, or 3 liter.
In 95 they made some slight modifications to the engine lighter pistons and rods.. which increased compression to 10.4/1 -- Bumped horsepower by 5.. (261base) -- This was the same in 95-96 models.
Which always makes me grin when people talk about how their 95 or 96 is 'faster' than the first gen.. There is no noticeable difference in power from 90-96.
In 97 further modifcations were made, mainly the Variable valve timing , slighting increase the CR to 10.5 -- But power output jumped to ~290bhp. There is a slight noticeable increase in feel from the 90-96 to the 97. Even at 30 more horsepower the 97 doesn't "smoke" any of the predecestrial LS 400's.
So in my opinion,.. if you run a 90-94 with 10.1 CR,.. 91 is all you need for 100% optimum function.
in a 95-96 , 91 should be just fine as well. 97+ models would probably benefit slightly from 93 octane.. but 91 , again, will do just fine.. and I would put money that on a Dyno no noticeable HP/Torque gain could be measured from 91 to 93,.. Or efficiency. In fact the opposite could be true on efficiency, but still so slight it is negligable.
People who think running 93 or 95,96,97,98,99,100-110+ octane is better, makes their engine faster, and so on -- In the 1UZ engines simply do not have a clue about how the engines operate. It is that simple.
I'm not pointing anyone out, or trying to make anyone feel bad, but people should be informed on what they are buying. Purchase the premium 93 all day long,.. I wouldn't smirk at anyone for that,.. I do it. But putting in octane booster, or trying to go beyond that -- Is a complete waste of money.. any effects you experience are placebo. (In the 1UZ).
I would smile if someone was adamant and trying to impose that I simply HAD to put 93 in my 1994 LS 400 when I picked up the 91 grade fuel nozzle.
As has been pointed out, and is quite obvious due to engine design.. The cars will run on anything from 87-93 (or higher) -- 87 won't damage the engine,.. the engine is designed to reduce itself depending on fuel quality. All I am saying is 91 is all the octane needed for 100% efficency, even in the 2008 models.
People will argue this fact all day long, but I will still stand behind it. =)
In 95 they made some slight modifications to the engine lighter pistons and rods.. which increased compression to 10.4/1 -- Bumped horsepower by 5.. (261base) -- This was the same in 95-96 models.
Which always makes me grin when people talk about how their 95 or 96 is 'faster' than the first gen.. There is no noticeable difference in power from 90-96.
In 97 further modifcations were made, mainly the Variable valve timing , slighting increase the CR to 10.5 -- But power output jumped to ~290bhp. There is a slight noticeable increase in feel from the 90-96 to the 97. Even at 30 more horsepower the 97 doesn't "smoke" any of the predecestrial LS 400's.
So in my opinion,.. if you run a 90-94 with 10.1 CR,.. 91 is all you need for 100% optimum function.
in a 95-96 , 91 should be just fine as well. 97+ models would probably benefit slightly from 93 octane.. but 91 , again, will do just fine.. and I would put money that on a Dyno no noticeable HP/Torque gain could be measured from 91 to 93,.. Or efficiency. In fact the opposite could be true on efficiency, but still so slight it is negligable.
People who think running 93 or 95,96,97,98,99,100-110+ octane is better, makes their engine faster, and so on -- In the 1UZ engines simply do not have a clue about how the engines operate. It is that simple.
I'm not pointing anyone out, or trying to make anyone feel bad, but people should be informed on what they are buying. Purchase the premium 93 all day long,.. I wouldn't smirk at anyone for that,.. I do it. But putting in octane booster, or trying to go beyond that -- Is a complete waste of money.. any effects you experience are placebo. (In the 1UZ).
I would smile if someone was adamant and trying to impose that I simply HAD to put 93 in my 1994 LS 400 when I picked up the 91 grade fuel nozzle.
As has been pointed out, and is quite obvious due to engine design.. The cars will run on anything from 87-93 (or higher) -- 87 won't damage the engine,.. the engine is designed to reduce itself depending on fuel quality. All I am saying is 91 is all the octane needed for 100% efficency, even in the 2008 models.
People will argue this fact all day long, but I will still stand behind it. =)
03-15-08, 04:23 PM
#53
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As for fuel, Lexus recommends at least 95 octane RON, so that's what I'll use.....simple.
03-15-08, 08:23 PM
#56
03-16-08, 08:37 AM
#57
Yes the second gen is faster -- But the years aren't just a one off -- A US spec 95 is only a hair faster than a 94. A 96 is faster than 95 -- Go read your specification sheets on the engine, not a general 'second gen 0-60 figure' 
-- I don't say this because I have a 94 and I am trying to make myself feel better... I've driven every year from 92 to 2001,.. Have had a 92, 93, 94, 95, 96 ,97, 99 and 2000 personally in the family at one point or another. Have a 99, 2000, and 1994 at the moment.
That is getting off topic though --
Back to octane.
Like I said people will disagree, and that is fine -- We are adults agree to disagree is what it is all about. 91 is all she needs,..
Yes, jfel, the detergents are included, but they are in all the octanes and of simliar amounts depending on the gas brand.
Take Chevron. Its 91 and 93 are identical (nearly) in forumula for cleanliness. The 87 isn't bad either.
-- I don't say this because I have a 94 and I am trying to make myself feel better... I've driven every year from 92 to 2001,.. Have had a 92, 93, 94, 95, 96 ,97, 99 and 2000 personally in the family at one point or another. Have a 99, 2000, and 1994 at the moment. That is getting off topic though --
Back to octane.
Like I said people will disagree, and that is fine -- We are adults agree to disagree is what it is all about. 91 is all she needs,..
Yes, jfel, the detergents are included, but they are in all the octanes and of simliar amounts depending on the gas brand.
Take Chevron. Its 91 and 93 are identical (nearly) in forumula for cleanliness. The 87 isn't bad either.
03-16-08, 02:29 PM
#58
Yes the second gen is faster -- But the years aren't just a one off -- A US spec 95 is only a hair faster than a 94. A 96 is faster than 95 -- Go read your specification sheets on the engine, not a general 'second gen 0-60 figure' -- I don't say this because I have a 94 and I am trying to make myself feel better... I've driven every year from 92 to 2001,.. Have had a 92, 93, 94, 95, 96 ,97, 99 and 2000 personally in the family at one point or another. Have a 99, 2000, and 1994 at the moment.
That is getting off topic though --
Back to octane.
Like I said people will disagree, and that is fine -- We are adults agree to disagree is what it is all about. 91 is all she needs,..
Yes, jfel, the detergents are included, but they are in all the octanes and of simliar amounts depending on the gas brand.
Take Chevron. Its 91 and 93 are identical (nearly) in forumula for cleanliness. The 87 isn't bad either.
-- I don't say this because I have a 94 and I am trying to make myself feel better... I've driven every year from 92 to 2001,.. Have had a 92, 93, 94, 95, 96 ,97, 99 and 2000 personally in the family at one point or another. Have a 99, 2000, and 1994 at the moment. That is getting off topic though --
Back to octane.
Like I said people will disagree, and that is fine -- We are adults agree to disagree is what it is all about. 91 is all she needs,..
Yes, jfel, the detergents are included, but they are in all the octanes and of simliar amounts depending on the gas brand.
Take Chevron. Its 91 and 93 are identical (nearly) in forumula for cleanliness. The 87 isn't bad either.
6.9sec 0-60
3650lbs
10.4:1 compression
260hp@5300
270lb-ft @4500
4spd trans
1994
7.9sec 0-60
3859lbs
10.0:1 compression
250hp@5600
260lb-ft@4400
4spd trans
1 whole second off 0-60 (when the final end ratios were the same) is pretty big....
as for the big company detergents vs. off-brand, iirc the same basic chemicals are used wherever you go, just in differing proportions, hell even warehouse gas has some additives in it. regardless, i use fuel injector cleaner every 4-6 months (lucas) and seafoam once a year so im pretty safe
Last edited by PureDrifter; 03-16-08 at 02:51 PM.
