This summers gas prices....

Interesting twist the thread has taken; 'right up my alley.
It's a common misconception that higher octane will make the combustion run hotter/cooler/slower, where, in fact, octane rating only denotes how resistant the mixture is to detonation. Believing you'll get lower temps when running higher octane fuel is more a function of low octane fuel leading to detonation which drives the combustion temps up. 'Not the desired situation...
During normal operation, the mixture in the combustion chamber doesn't explode, but actually burns at a controlled rate across the top of the piston. The hope is that it finishes burning at the same time that the piston reaches TDC, which is why the ignition has to fire the plug before TDC (thus, ignition advance). As it's burning, both pressure and heat rise. If either exceeds the auto-ignition point (the point where the mixture will spontaneously combust), you get a nasty pressure spike while the piston is still rising. That's detonation, and what you hear as a "knock". Run high enough octane rating that you don't get detonation. Running anything higher than that will not gain you anything but a lighter wallet.
So, after all of that, I discovered something interesting with my late-model turbo car; even though it's designed to run just fine one 87 octane fuel, by changing to 91 octane, not only does it run noticeably better, but it gets enough better mileage that it more than offsets the price difference. The assumption is that the cornputer was pulling the timing a lot more than I realized.
 
Nater Potater said:
Interesting twist the thread has taken; 'right up my alley.
It's a common misconception that higher octane will make the combustion run hotter/cooler/slower, where, in fact, octane rating only denotes how resistant the mixture is to detonation. Believing you'll get lower temps when running higher octane fuel is more a function of low octane fuel leading to detonation which drives the combustion temps up. 'Not the desired situation...
During normal operation, the mixture in the combustion chamber doesn't explode, but actually burns at a controlled rate across the top of the piston. The hope is that it finishes burning at the same time that the piston reaches TDC, which is why the ignition has to fire the plug before TDC (thus, ignition advance). As it's burning, both pressure and heat rise. If either exceeds the auto-ignition point (the point where the mixture will spontaneously combust), you get a nasty pressure spike while the piston is still rising. That's detonation, and what you hear as a "knock". Run high enough octane rating that you don't get detonation. Running anything higher than that will not gain you anything but a lighter wallet.
So, after all of that, I discovered something interesting with my late-model turbo car; even though it's designed to run just fine one 87 octane fuel, by changing to 91 octane, not only does it run noticeably better, but it gets enough better mileage that it more than offsets the price difference. The assumption is that the cornputer was pulling the timing a lot more than I realized.
Click to expand...

The EcoBoost runs fine on 87 but makes its full advertised power on 93 and does enough for the gas mileage to be worth the extra spend.
and then there’s the 100 octane tune :D


What’s your take on stepping up the octane to limit timing retardation under high load and high IAT (like cruising 4K sucking Florida bilge air)
 
Another misconception is that higher octane will give you more power or better fuel mileage. Neither is true. However, if you run octane lower than required then it can pull power out of the engine as mentioned above. This is done by retarding timing. If you experience no knock with 89 octane then running 93 will not be any better.
Back in the early 90's I had a 1970 Olds W31 and got about 10 gallons of Cam II to top off my tank and had the kid pumping it tell me the whole 'it runs hotter' crap. I built that motor and knew all about octane so just giggled and said 'yeah I know'
 
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Nater Potater said:
Interesting twist the thread has taken; 'right up my alley.
It's a common misconception that higher octane will make the combustion run hotter/cooler/slower, where, in fact, octane rating only denotes how resistant the mixture is to detonation. Believing you'll get lower temps when running higher octane fuel is more a function of low octane fuel leading to detonation which drives the combustion temps up. 'Not the desired situation...
During normal operation, the mixture in the combustion chamber doesn't explode, but actually burns at a controlled rate across the top of the piston. The hope is that it finishes burning at the same time that the piston reaches TDC, which is why the ignition has to fire the plug before TDC (thus, ignition advance). As it's burning, both pressure and heat rise. If either exceeds the auto-ignition point (the point where the mixture will spontaneously combust), you get a nasty pressure spike while the piston is still rising. That's detonation, and what you hear as a "knock". Run high enough octane rating that you don't get detonation. Running anything higher than that will not gain you anything but a lighter wallet.
So, after all of that, I discovered something interesting with my late-model turbo car; even though it's designed to run just fine one 87 octane fuel, by changing to 91 octane, not only does it run noticeably better, but it gets enough better mileage that it more than offsets the price difference. The assumption is that the cornputer was pulling the timing a lot more than I realized.
Click to expand...

Mazda rates my turbo engine as making 232 HP on 87 octane and 250 HP on 93 octane, FWIW. The car runs ok on 87, but is noticeably quicker on 93.
 
Blueone said:
So Saturday delivery……..Sitting at a bar having lunch at 2:30 in the afternoon last week. This woman sits down beside me in a usps uniform probably 35. She just got finished her deliveries. We get talking about Saturday deliveries…. I think they are ridiculous…. She loses her shit… union was first word out of her mouth. Her point was they can’t carry 6 days of mail in 5 days….. keep in mind she is in a bar at 2:30 being paid her shift isn’t over. She took her beer and moved down the bar….. that hurt a bit :(
The government shouldn’t run anything let alone a country
Click to expand...
How did she look in her UPS uniform?
 
BTW, what ever happened to that WOKE newbie Force Majeure? Haven't heard from that fella in a while? :D I guess his therapist must have advised him to double up his medicinal CBD and meditate to reduce anxiety on his pipeline concern. Dope
 
Ha ha....just noticed you're from New England. That explains a lot!

Ok, supply and demand.... Cut the supply, prices go up. Maybe once you've worked through your issues you might want to take a course on basic economics Mr. Kennedy?
 
Paid $4.65 for non-ethanol at the pump yesterday. That's at a Murphy station which is usually competitive.

On a happier note my flight from Florida to Dallas just got canceled so now I have to stay in 80° instead of going to 23°.

Darn it
 
We are screwed for fuel….. damn sail boaters win again

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