Whats the verdict: is there a mechanical difference that justifies the octane difference? Past LX and Land Cruiser models have the EXACT same engines, is there a difference now? There has been some discussion in the past but no clear answer. Toyota's posted response was vague. I understand the ECU will compensate for timing if lower octane fuel is used....but is there a mechanical or engineering reason? Please chime in if you're well informed, have concrete mechanical knowledge, or know some specifics.
87 vs 91 Octane: LC vs LX570 (1 Viewer)
- Thread starter ConcreteCruiser
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The answer was more expensive fuel for the more expensive vehicle.
For vanity sake.
Or some such.
For vanity sake.
Or some such.
Markuson
SILVER Star
This question was beaten to death a while back for LC drivers. It's been pretty well established (to my satisfaction, anyway) that there is no discernible advantage on the LC by paying more for 91. I have now proven it to myself on two very long road trips (11,000 miles) that there was literally ZERO difference in MPG, power or performance, regardless of altitude or RPMs.
Given that the LX claims a mere 2 HP difference, I can't imagine there's a whole heck of a lot in there that could truly require it...but what do I know... You only wanted mechanical experts, etc.
Meanwhile... Exxon, BP and Shell thank you for your premium business.
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Taco2Cruiser
Crazy American Off Road
^^^ pretty much.
Since octane only changes the point in which detonation happens, 87 is all a 5.7 needs. And if thinking 91 or 93 octane is better. Consider that modern gasoline with ethanol begins to breaks down around 60 days. Most people buy 87, so a regular gas stations supply is replenished more often. Yes premium gas holding tanks are smaller, but if you want good fuel, get whatever is fresh and don't fill up and the day of fuel delivery, all that sediment at the bottom just got churned up and has a better chance to get past the station filters and into your tank.
Since octane only changes the point in which detonation happens, 87 is all a 5.7 needs. And if thinking 91 or 93 octane is better. Consider that modern gasoline with ethanol begins to breaks down around 60 days. Most people buy 87, so a regular gas stations supply is replenished more often. Yes premium gas holding tanks are smaller, but if you want good fuel, get whatever is fresh and don't fill up and the day of fuel delivery, all that sediment at the bottom just got churned up and has a better chance to get past the station filters and into your tank.
yes, a huge difference. If you notice specs, you get extra 2HP on LX. Put 93 and may get couple more.
- Thread starter
- #9
I'm thinking 87 octane will work just fine.
Markuson
SILVER Star
I got a better magnet trick for MPG:
I'ma putting rare earth magnets all over the underbelly of me 200...
Then Ima glue a bunch o opposite pole magnets on the roads I drive.
Then? Ima LEVITATE to work. Wooooo!
FinallyGotOne!
SILVER Star
This reminds me of the old saying "Unlike a man with one watch, a man with two watches never knows exactly what time it is."
I wanted to run some fuel consumption tests so I could decide for myself if I should pay the extra dollar or two for 91 octane. However, prevailing winds make such a difference on fuel economy that it quickly became clear I would never be bale to drive a long distance in the same conditions. I do have the ability to monitor instantaneous fuel flow, but I am not sure that the ECM changes spark timing immediately upon sensing a change in octane, or if it is changed over some unknown period of time, so that wouldn't be a good test either.
Bottom line: I've been burning 87 in my LX for a year with no perceived difference in fuel economy or towing power.
I wanted to run some fuel consumption tests so I could decide for myself if I should pay the extra dollar or two for 91 octane. However, prevailing winds make such a difference on fuel economy that it quickly became clear I would never be bale to drive a long distance in the same conditions. I do have the ability to monitor instantaneous fuel flow, but I am not sure that the ECM changes spark timing immediately upon sensing a change in octane, or if it is changed over some unknown period of time, so that wouldn't be a good test either.
Bottom line: I've been burning 87 in my LX for a year with no perceived difference in fuel economy or towing power.
Markuson
SILVER Star
If you just keep track over time...prevailing winds become less and less a factor as they average out.
When premium fuel costs 10=20% more...it would take one heck of a wind...ALWAYS blowing for or against you...to not find convincing evidence against premium.
If you have a Costco near you premium (93) cost a mere .20 more than 87 and total price is 2.27. At shell you have 93 at 2.89 while regular is 2.07...
I use premium and here is why:
*I can afford to
*I prefer my ecu not to pull timing to compensate
*Lower octane can create a pinging and knocking noise.
*I put my foot in it
*Plan to keep a long time
However lower octane does not create more or less deposits...
If you are concerned about quality of gas research top tier gas and this may forever end the debate of "should you use 87 or 93." Top tier gas stations have more detergents than gas stations that are not on the list of top tier.
Wrap up
Don't be too concerned about today's quality of gas since it is still miles better than 20-30 years ago and cars from those times can still be seen driving..
I use premium and here is why:
*I can afford to
*I prefer my ecu not to pull timing to compensate
*Lower octane can create a pinging and knocking noise.
*I put my foot in it
*Plan to keep a long time
However lower octane does not create more or less deposits...
If you are concerned about quality of gas research top tier gas and this may forever end the debate of "should you use 87 or 93." Top tier gas stations have more detergents than gas stations that are not on the list of top tier.
Wrap up
Don't be too concerned about today's quality of gas since it is still miles better than 20-30 years ago and cars from those times can still be seen driving.
.
There's a lot of sensible advice in this thread. But I'd like to ask another question: those of you who are also part sports car forums where the consensus is "you must use premium" (with the high compression ratio of a strung out NA or turbo engine it makes sense)....
Do you feel the Lexus LX570's ECU is optimized for premium fuel?
It's like when people are putting race gas in their sports cars and people say "Hey you need a tune for your engine to take advantage of it"
I agree the LC doesn't need premium but what about the LX?
Do you feel the Lexus LX570's ECU is optimized for premium fuel?
It's like when people are putting race gas in their sports cars and people say "Hey you need a tune for your engine to take advantage of it"
I agree the LC doesn't need premium but what about the LX?
Besides octane, is it worth any extra expense to buy gas with better additives to prevent carbon, sludging, gunk over many, many miles?
Taco2Cruiser
Crazy American Off Road
No, the concentration isn't enough to justify the additional cost. Use Cheveron Techron or Amsoil P.I. fuel clearers, and have more detergents and cleaners that any premium out there and the cost of one of those bottle every 4,000 miles will still be cheaper than paying for premium.
This is again something you have to decide for yourself... I have a cruiser but I use 93. The reason for higher octane is overall performance, nothing more. Your ECU will compensate for 87 but at the cost of pulling timing.
Octane has nothing to do with additives to be honest.
Higher octane = more performance
Additives = cleaner burning fuel
Top tier gas station have more detergents than required by government for all gasoline stations. This means top tier 87-93 have more additives/detergents.
Taco2Cruiser
Crazy American Off Road
^^^ the word "performance" is so overused, because it is talked too much with a "feeling" and not tangible results. When the ECU starts to detect a high octane, is can start to learn to use is better. But it is so negligible, and timing isn't really advanced or retarded enough to even see a consistent improvement of a vehicle that doesn't require it. We don't have turbos or high compression.
If you really want to talk timing, I doubt anyone is replacing cam exhaust gears by manually advancing timing about 3 degrees, lowering the thermostat temp not less than 10 degrees, and eliminating the stock ECU for their personal mapping to even start to kinda see an improvement, and that would be also with cutting the catalytic converters out. I dyno after everything I do, and 91/93 octane on a stock and unmodified engine that does not require it from the factory and just says "recommended" is a waste of money. Sorry rant over.
If you really want to talk timing, I doubt anyone is replacing cam exhaust gears by manually advancing timing about 3 degrees, lowering the thermostat temp not less than 10 degrees, and eliminating the stock ECU for their personal mapping to even start to kinda see an improvement, and that would be also with cutting the catalytic converters out. I dyno after everything I do, and 91/93 octane on a stock and unmodified engine that does not require it from the factory and just says "recommended" is a waste of money. Sorry rant over.
Markuson
SILVER Star
Can you provide evidence of this "performance" advantage based on fuel in the LX? I ask because I've never seen anyone substantiate this. If someone can, I'd love to see it. Until then, I remain convinced it's all in the head (and wallet).
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Ah yes, the good ole Octane Thread.
