93 or 87 and why?

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Asdjonasd

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Because turbo engines have higher compression....higher octane rating is better in turbo engines. Period.

Chemically, octane 8 carbon chain. Heptane 7 carbon .......butane 4 carbon , propane 3 carbon, get the point.

Octane handles more compression than heptane before spontaneous ignition (versus by spark plug).

"Octane Rating" is ratio of octane/heptane.

91 Octane represents performance of blend of 91% octane, 9% heptane.

(usually it's a mix of carbon chain lengths that have equivalent performance as mixing 91% and 9%)

Engines knock when gas ignites before spark plug fires...because the cylinder compression forces combustion before sparkplug fires off.

TL;DR Higher octane = higher efficiency and better timing of fuel ignition by spark plug. Ideal for turbo engines if you want the fuel to ignite where and when it was designed to within the engine.

Source: chemist
 

Asdjonasd

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Oh.... what about 110 octane? it has better knocking characteristic / higher ignition temp than the reference fuel - pure 'octane'
 

df4801

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Because turbo engines have higher compression....higher octane rating is better in turbo engines. Period.

Chemically, octane 8 carbon chain. Heptane 7 carbon .......butane 4 carbon , propane 3 carbon, get the point.

Octane handles more compression than heptane before spontaneous ignition (versus by spark plug).

"Octane Rating" is ratio of octane/heptane.

91 Octane represents performance of blend of 91% octane, 9% heptane.

(usually it's a mix of carbon chain lengths that have equivalent performance as mixing 91% and 9%)

Engines knock when gas ignites before spark plug fires...because the cylinder compression forces combustion before sparkplug fires off.

TL;DR Higher octane = higher efficiency and better timing of fuel ignition by spark plug. Ideal for turbo engines if you want the fuel to ignite where and when it was designed to within the engine.

Source: chemist


Now I got it. 110 octanes is 110% octane and (-10%) heptane.
 

Ron Lanza

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just ran my complamentry tank dry from the dealer. Im not sure but assume they filled it up with the cheap stuff ?
Shoul I try 93 and see if there is a difference ? especially during brake in period ??
 

Russ103

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just ran my complamentry tank dry from the dealer. Im not sure but assume they filled it up with the cheap stuff ?
Shoul I try 93 and see if there is a difference ? especially during brake in period ??

Forget that 87 even exists. Save that for rental cars.

The Raptor/Limited (according to a dyno done by Car & Driver referenced in this thread) puts down an extra 20hp more on 93 vs 87. What more proof do you need?

I personally can’t believe that people would even consider putting in the cheap stuff that the masses (read: non car/truck people) use.
 

isis

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just ran my complamentry tank dry from the dealer. Im not sure but assume they filled it up with the cheap stuff ?
Shoul I try 93 and see if there is a difference ? especially during brake in period ??
Guy I bought my truck from apologized for not having a full tank. I thanked him for it when he said he always ran 87...

i know he didn’t hurt it but that’s just not what I wanted in there and it takes me weeks to burn a tank of gas.
 
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