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PREMIUM-VS-REGULAR GAS FOR 2024 GT??

Cavedog

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Is it worth it? Ford says 87 octane is just fine the 5 liter. They have a safety factor calculated in. They wouldn't have a very good engineering department if they didn't. The 5 liter would probably run just fine on 85 octane. There is limit on just how low before you develop problems. It works the same way with exceedingly high octane. After a point higher octane does no good. If you are concerned with the maximum performance available all the time buy the highest octane you can afford. If it wasn't for the computer controlling timing the 5 liter would be pinging and knocking on 95 octane. Some of use are concerned about cost. If you divide the cost of reg into the cost of premium and multiply that with average mpg you have the milage you must get to break even. Premium $4 divided reg $3 times let say 25 mpg means you must get 33.33 mpg to break even. That is strictly economics. If you are getting 28 mpg on premium and switch to reg and get 25 mpg. Devide 28 by 25 and multiply by $3 you get $3.36. That is the maximum you should pay for premium.
If your Mustang is a daily drive you will never notice the reduction of power. If you are running for pink slips, use the highest octane you can find. I wouldn't want you to loose ride.
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Gregs24

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Is it worth it? Ford says 87 octane is just fine the 5 liter. They have a safety factor calculated in. They wouldn't have a very good engineering department if they didn't. The 5 liter would probably run just fine on 85 octane. There is limit on just how low before you develop problems. It works the same way with exceedingly high octane. After a point higher octane does no good. If you are concerned with the maximum performance available all the time buy the highest octane you can afford. If it wasn't for the computer controlling timing the 5 liter would be pinging and knocking on 95 octane. Some of use are concerned about cost. If you divide the cost of reg into the cost of premium and multiply that with average mpg you have the milage you must get to break even. Premium $4 divided reg $3 times let say 25 mpg means you must get 33.33 mpg to break even. That is strictly economics. If you are getting 28 mpg on premium and switch to reg and get 25 mpg. Devide 28 by 25 and multiply by $3 you get $3.36. That is the maximum you should pay for premium.
If your Mustang is a daily drive you will never notice the reduction of power. If you are running for pink slips, use the highest octane you can find. I wouldn't want you to loose ride.
Why put cheap fuel in a performance car? There is more to it than octane as well (certainly here in the UK) where premium fuels have more detergents etc. Price difference varies enormously too between premium and standard fuels.

Your fuel is so cheap anyway!

You will pay more in depreciation than you will the small difference in fuel price
 

MAT1955

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Racer's mantra "Good fuel keeps the engine cool" ......full synthetic oil and minimum 91 octane for long engine life.
 

robvas

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According to ford:

1. 87 octane is fine

2. you never need to change your tranny fluid

3. don't change the oil until the car tells you too even if it's 10,000 miles

does any of this sound like a good idea?
 

Starship Enterprise

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This is a high performance sports car. You think people are over there on the Ferarri board arguing over what’s the cheapest octane gas they can put in?

Yeah, the Mustang isn’t a Ferrari, but it ain’t a Prius either.

Putting 87 octane in this car is just disrespectful.
 


Frogdog1

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Anyone that is budget strained between octanes shouldn't have bought the car. The only 87 my car has seen was the dealer fill up when brand new. Yes, the car ran. LIke someone else said in so many words, same thing with oil, use synthetic instead of dead dinosaur oil. Yeah it costs more but those kind of costs shouldn't matter to a 5.0 owner. It's just money. "Pay me now or pay me later".
 

MAT1955

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@Starship Enterprise ...... well' I'll be - just proves there are dumba$$es everywhere. We built a 383 stroker, marine version (different cam), for a guy. He called back a few months later said it was "running like shit" . It definitely was off when we ran it. Dumba$$ was using cheapest jobber's 87 he could find. In his engine build customer notes (in BOLD) and on a sticker we placed in engine bay - this engine requires 91 octane ..... we recommend Shell, Mobil, Sunoco. There's just no fixing stupid.
 

Cavedog

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Regular vs premium which is better for an engine? Both use the same base with more or less octane additive. Premium gives more hp. By goosing up the hp, cylinder pressures are increased and consequently bearing, rings and every component in the drive system. You decide which is better for your car.
 

Gregs24

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According to ford:

1. 87 octane is fine

2. you never need to change your tranny fluid

3. don't change the oil until the car tells you too even if it's 10,000 miles

does any of this sound like a good idea?
Agree on the first two (as in the opposite) but 10k mile oil changes are just fine with modern engines and oils. 20k is pushing it mind you.
 

Gregs24

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Regular vs premium which is better for an engine? Both use the same base with more or less octane additive. Premium gives more hp. By goosing up the hp, cylinder pressures are increased and consequently bearing, rings and every component in the drive system. You decide which is better for your car.
Not really. Those maximum pressures are transient at very high revs / peak power which happen occasionally. Reducing the risk of pre-ignition and detergents work at a all revs and all the time.
 

robvas

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Agree on the first two (as in the opposite) but 10k mile oil changes are just fine with modern engines and oils. 20k is pushing it mind you.
Most mechanics that see what these engines look like with those 10mm oil changes will disagree with you

just because an oil passes an online oil test doesn't mean it's not causing problems in your engine
 

Starship Enterprise

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@Starship Enterprise ...... well' I'll be - just proves there are dumba$$es everywhere. We built a 383 stroker, marine version (different cam), for a guy. He called back a few months later said it was "running like shit" . It definitely was off when we ran it. Dumba$$ was using cheapest jobber's 87 he could find. In his engine build customer notes (in BOLD) and on a sticker we placed in engine bay - this engine requires 91 octane ..... we recommend Shell, Mobil, Sunoco. There's just no fixing stupid.
These are the people that order a filet mignon and then put ketchup on it. :cwl:
 

Cavedog

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No these are the people that order ribeye for the extra flavor and keep a few bucks in there pocket.
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