Weird. I run 85 in my 2015 whenever I am in Utah, Idaho, or Colorado. Often pulling my tear drop trailer (2500 lbs) off road, over passes, etc.
Fuel, premium vs regular
- Thread starter chefbige09
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bloc
SILVER Star
Same.
That's part of the crux of octane. It's role is not just for nominal conditions. Octane really comes into play during high barometric pressures, high load, high stress, hot weather, at peak volumetric efficiency/torque peaks. Yes, at elevation can use less octane because there's less cylinder filling/heat. But bring that fuel back to lower elevations and that's a problem.
There's also a spectrum to knock. We don't all drive the same or feel things the same. Some knock cannot be felt and needs knock ears to perceive and sensors to measure.
Low grade knock doesn't result in outright engine failure. It's often long term effects of carbon buildup because of uncontrolled flame fronts, lost compression, oil burning, catalytic impacts, etc.
There's also a spectrum to knock. We don't all drive the same or feel things the same. Some knock cannot be felt and needs knock ears to perceive and sensors to measure.
Low grade knock doesn't result in outright engine failure. It's often long term effects of carbon buildup because of uncontrolled flame fronts, lost compression, oil burning, catalytic impacts, etc.
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Is anyone driving around with proper electronics to truly see exactly the parameters you’re referring to (aside from maybe Monica)? What would that look like aside from a laptop constantly connected, or a Motec like they run in the Middle East?
Some generalized outputs can be watched over OBD-II. That's probably the best for everyone to do, as it takes into account the individual car/condition, driver, use case, etc.
You can monitor Knock Learn Value (KLV), Knock Correction Learn Value (KCLV), and Ignition timing.
These values are not singular the ECU has diffferent values for different load regions. Also the OBD-II interface is slow and delayed so singular snapshots really do not tell the whole story.
They can be useful. We don't know the nonminal values for our cars yet but we can try to figure them out.
It's a shame there's so many smart-a** replies about this. I feel like it's a legitimate question. If it's been covered ad-nauseum for years, why not just state what the conclusion was from what thread?
IMO, It's probably a real question for those of us that might be new to the LX570's that have stickers on them stating the requirement of PREMIUM FUEL ONLY, but might also have the exact engine in another vehicle, that takes all the same exact parts, but only requires 87.... And we might be educated about the mid-2000's FJ Cruisers that specified premium fuel only AND Toyota meant it in this case....and maybe some 4-Runners? If you didn't use premium, it could and in most cases, did cause severe engine damage to those 4.0L engines.
It's not that big of a deal to me, we can generally get fuel at Costco and premium is about the same price there as 87 is at all other stations in the area. Do I want to still pay $.20 less a gallon and use 87? Yes.
What do I do? We mix.... Fill-up with premium and try to refill at 1/2 tank and use 87. Vice-versa.
IMO, It's probably a real question for those of us that might be new to the LX570's that have stickers on them stating the requirement of PREMIUM FUEL ONLY, but might also have the exact engine in another vehicle, that takes all the same exact parts, but only requires 87.... And we might be educated about the mid-2000's FJ Cruisers that specified premium fuel only AND Toyota meant it in this case....and maybe some 4-Runners? If you didn't use premium, it could and in most cases, did cause severe engine damage to those 4.0L engines.
It's not that big of a deal to me, we can generally get fuel at Costco and premium is about the same price there as 87 is at all other stations in the area. Do I want to still pay $.20 less a gallon and use 87? Yes.
What do I do? We mix.... Fill-up with premium and try to refill at 1/2 tank and use 87. Vice-versa.
I tested about 100 tanks of fuel, about 70 with 91 octane and 30 with 87 octane and for me 91 octane returns ~3% better MPG.
I'm not worried about MPG. You were getting better MPG because, believe it or not, there was most likely less ethanol in the premium.
I'm worried about long-term catastrophic engine damage.
Not sure why you would believe premium has less ethanol.
Btw, those FJ's that need to run premium actually don't, my 4.0 runs 87 and has for the past 200k miles without issue.
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I wasn't replying to you. Just providing facts relevant to the topic of the thread.
I agree. FJ having engine issue due to regular gas?? That is news to me. BUT i did hear plenty about fender bulging due weak frame.
I have seen the fender bulge, though I have no personal experience with it
Man those are good Costco Gas prices. I gassed up the 200 (regular) and the wife's BMW (premium) just last night. Difference per gallon at Costco? 68 cents a gallon. 20 cents would be a bargain!
Her twin turbo BMW SUV, with almost as much HP as my 200, regularly gets 37 mpg on the highway. Pretty nice car but definitely not a 200.
bloc
SILVER Star
Because new people have a responsibility to do a little research, and they end up getting far more context and information if they do so vs just post and have a couple people state a single octane number.
There is an incredible base of knowledge posted on this forum. Everyone is better off if people actually use it.
bloc
SILVER Star
Severe engine damage from RUG in a truck platform sounds very un-Toyota-like
The answer is there fully in front of you and couldn't be more clear. To reinforce::
What you want to hear maybe something else. Leaving it to anecdotes of others, none that I have heard with any formal understanding or background in the matter, some that don't even own an LX and are suggesting for you to put something on the line, should be taken with a grain of salt.
As a tuner in a previous life, and professional background in tuning aircraft motors, I will only fill mine with 91 octane. No, I don't believe it'll results in catastrophic failure, but later in life, may result in premature things like lost compression, carbon buildup causing even more knock, catalytic converter failures, etc.
If there's anything you should take away, do not alternate fuel grades on fill-ups.
bloc
SILVER Star
This. Disagree as we may on how these vehicles can protect themselves, every bit of evidence we have is that the vehicle needs a few tanks to settle in on learned knock values. Constantly changing the octane keeps it guessing and that is not the way to get the most out of the vehicle, with regard to longevity, efficiency, etc.
