Quickest and safest way to go from 87 Octane to 91 Octane

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Also not sure if this is sarcastic. If it is not, STOP WORRYING, go drive your Jeep. Fill it up whenever your heart desires. You will do NOTHING to harm your vehicle. Worse case scenario in about 40K miles you might get some knocking from using 87 octane. Again nothing will harm the engine.
No, not sarcastic. Genuine concern - I am a worrier - it is a big investment.
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Is it safe to run rocket 100 in my car;
ANSWER FROM ROCKET FUEL: It's safe...ish to use on stock engines. The fuel burns cooler and may clog your catalytic converter. Youcertainly won't see any better power or mileage from it, unless you're tuned for 100 octane. It's sold solely for cars that are tuned for 100 octane: race cars and offroaders
 

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No, not sarcastic. Genuine concern - I am a worrier - it is a big investment.
Luckily that's one area where no worries are needed. Confirming lug nut torque, oil fill levels, other fluid reservoirs, etc. those are things you should confirm after EVERY service, or just DIY and confirm it as you do it :)
 
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How exactly does the knock sensor and the ECU function - I am aware that the knock sensor basically has a piezoelectric crystal listening at a frequency - that of a ping. Once it detects a vibration at that frequency, it sends a voltage to the ECU which then retards the timing of the spark to prevent detonation.
I am curious to find out if the timing is retarded proportionally to the fuel mixture. In my case as I am graduating from 87 (filled by the dealer) to 91 in incremental fill ups over time, and my fuel mixture is a little over 89, is the timing retarded proportionally or is it retarded to an absolute value regardless?
In other words or a different way to ask the same question is, if I am at 87 octane, would my engine performance be more degraded than if am at 89.5 octane?
 

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It will retard the timing based on whatever octane it detects, so it will gradually advance the timing as you get closer to full 91 Octane. Probably take about 3 more full tanks of 91 to be at the performance level of true 91 Octane but TBH you won't really notice much difference since it will be over such a prolonged time. I wouldn't lose any sleep over this, if you have a 401k I'd me much more concerned about that.
 
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It will retard the timing based on whatever octane it detects, so it will gradually advance the timing as you get closer to full 91 Octane. Probably take about 3 more full tanks of 91 to be at the performance level of true 91 Octane but TBH you won't really notice much difference since it will be over such a prolonged time. I wouldn't lose any sleep over this, if you have a 401k I'd me much more concerned about that.
Thanks - I learn so much on this forum!
BTW, my IRA is already down 15% since the last few months. :(
Hopefully the first half of 2019 is better on the markets than the second half of 2018.
 

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Thanks - I learn so much on this forum!
BTW, my IRA is already down 15% since the last few months. :(
Hopefully the first half of 2019 is better on the markets than the second half of 2018.
That's not going to get better anytime soon. Can't help you with that one, the stock market is insane right now - nothing makes sense except to short-term investors trying to capitalize on short-term gains, and that doesn't bode well for the long-term economy. House of cards and all, and we've been propping up a mess with low interest rates for a while now. It eventually has to fall down so it can be re-built. Hopefully this next round on a more stable base of mid/long-term investments (not holding my breath).

You used to invest in companies you believed in and that had long-term visions that aligned with yours, and the market was comprehensible. Now it's computers vs. computers all trying to maximize pennies on short-term trades at insanely high volumes to generate gains, and people capitalizing on this as well. The long-game folks are just collateral damage in the short-term, but will be fine mid/long.
 

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It will retard the timing based on whatever octane it detects, so it will gradually advance the timing as you get closer to full 91 Octane. Probably take about 3 more full tanks of 91 to be at the performance level of true 91 Octane but TBH you won't really notice much difference since it will be over such a prolonged time. I wouldn't lose any sleep over this, if you have a 401k I'd me much more concerned about that.
To be clear, there is no octane detector; the timing is just advanced (with a hard limit, which is why running higher than 91 won't give even more power) until knock occurs, then backed off slightly. This happens periodically, which is why it takes a little for it to 'learn' the fuel mixture you have. I do agree with the tank suggestion though, just fill up normally the next few times with 91, as you would, and you'll probably be running optimally for the engine.
 

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You could use Torco Octane booster. They sell it on Amazon
 

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I'm on my first tank and really don't know what the octane the dealer used. It is what it is, but I'll wait until I'm almost empty before filling up with higher octane. Milage right now sucks, but it's only at 150 so I'll let it have a few break-in miles on whatever gas is in it before I worry about my mileage. Unless you are almost empty topping off with 91 octane every so often will take several tank fulls before you actually have a full tank of 91
 
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I'm on my first tank and really don't know what the octane the dealer used. It is what it is, but I'll wait until I'm almost empty before filling up with higher octane. Milage right now sucks, but it's only at 150 so I'll let it have a few break-in miles on whatever gas is in it before I worry about my mileage. Unless you are almost empty topping off with 91 octane every so often will take several tank fulls before you actually have a full tank of 91
My gas tank should be around 90.5 octane - I am filling 91 when it gets to half.
I have done 800 miles so far - averaging 21.5 mpg.
 
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You could use Torco Octane booster. They sell it on Amazon
I read that Torco will put an orange residue on the spark plugs.
 

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I guess if you really wanted to get rid of it that bad you could have just gone to a diner, stuck a siphon hose in your tank, and taped a sign to the Jeep saying "FREE GAS HERE - HELP YOURSELF!". Go inside and have a breakfast or coffee and come out and drive straight to the nearest gas station and filled up with 91.
 

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I happen to have a Rebel Gas Station just a mile down the street from my home. They have 100 Octane Oxygenated Unleaded fuel. I am wondering if "Oxygenated" may mean too much Ethanol maybe? If I fill a couple of gallons of 100, I will reach 91 immediately. But is there any risk?
Or is there more risk in driving with 87 with some carbon deposits while I reach 91?
I think you may be overthinking the situation. To the other's points, I'd just use the 87, then refill with 91 when your tank is empty. On a related note, my daughter's 2004 Volvo XC90 requires 91, however, we've been putting 85 in it for years. It's a 2.5L 5 Cylinder Turbo motor. Runs fine on the lowest grade. Also, my previous BMW's required premium. Of course, I liked to put premium in, but again, but have put in lesser grades. Also ran fine. My 2 cents.
 
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I guess if you really wanted to get rid of it that bad you could have just gone to a diner, stuck a siphon hose in your tank, and taped a sign to the Jeep saying "FREE GAS HERE - HELP YOURSELF!". Go inside and have a breakfast or coffee and come out and drive straight to the nearest gas station and filled up with 91.
Believe me, I though of siphoning the 87 out. :D
 
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