Premium fuel or Regular? GT Coyote V8

fewt said:

I'm familiar with the owner's manual, you're quoting page 125. Like I said, 87 is fine for sitting in traffic. Their (Ford's) specifications page that I linked previously states that the HP/TQ ratings are using premium fuel. You're not going to get the best performance with 87, but if you're racing from stop light to stop light that's ok.

I've posted this before, but here's a dyno of 87 vs 93 from a stock 2011 5.0.

Click to expand...

87 is fine for everything, that is why it's the recommend fuel of type.

For any type of track duty, I would for sure go with 93 octane. But that's not what 99% of us use these for on a daily basis.

As for the dyno, I am familiar with what you posted. I have yet to see any dyno comparison of the S550 coyote.

millhouse said:

So it 87 isn't just "ok" here, it's recommended for daily driving. If I decide to take it to the track, I will absolutely put in 93 octane for heavy duty use. I will likely change the engine oil to something a bit more heavy duty as well. But for the daily driver, IMHO...93 octane is a complete and udder waste.

Click to expand...

Till you come across the same mustang as yours and get beat because he put premium.

millhouse said:

Except, the quality of 93 octane is no better than the quality of 87 octane...that is where your logic is flawed.

As for your viper...unlike the mustang it recommends a minimum of 91 octane premium. No one here suggest you do otherwise.

A better analogy using restaurants is to compare Top Tier stations to non Top Tier stations. I would then wholeheartedly agree.

Click to expand...

I searched youtube for coyote engines, but came up with no results. There was an EB mustang video and charger r/t video octane comparison from RP Productions. You're paying more for performance, even if it is incremental.

Please explain how you think 87 vs 93 octane, 93 octane is "no better quality". You think they will produce the same power? :lol:

millhouse said:

Terrible analogies.

Premium and regular perform the same function here...the premium just allows the engine to run slightly more timing. This isn't a difference between Ruth's Chris and Applebees, it's a difference between tap water and bottled water. Both do the same thing, one just costs more.

Click to expand...

I really dislike analogies and anecdotal claims even more.

Ruth's Chris? Please. Bones or Chops? Now you're talking. And Dasani is bottled from our tap water out on Hwy 41.

Whatever. Run what you want. Also the following is an interesting read.

http://www.nacsonline.com/YourBusiness/FuelsReports/2015/Fuels/Pages/The-Value-of-Premium.aspx

I ran a tank of regular once. The difference is noticeable, not glaring but it is there. It just doesn't feel as sharp, I can't come up with a better term than that.

I get that some people maybe don't want to or simply can't afford premium, but I am fortunate enough that the cost is not an issue so I'll continue using premium.

millhouse said:

87 is fine for everything, that is why it's the recommend fuel of type.

As for the dyno, I am familiar with what you posted. I have yet to see any dyno comparison of the S550 coyote.

Click to expand...

You own a S550 coyote, if you can't accept the data because of a minor revision change to the motor maybe you can run your car on a dyno and share?

Ford literally states that the motor makes 435HP on premium fuel. They stopped publishing what the motor makes on 87 when the 2013 landed.

1mic said:

I searched youtube for coyote engines, but came up with no results. There was an EB mustang video and charger r/t video octane comparison from RP Productions. You're paying more for performance, even if it is incremental.

Please explain how you think 87 vs 93 octane, 93 octane is "no better quality". You think they will produce the same power? :lol:

Click to expand...

Just because one produces more power (in some vehicles) does not mean the quality is the same. The fuel quality and octane are not synonymous. 93 octane contains no more additives than a comparable 87 octane fuel. 93 will not burn cleaner, or be better for any engine not designed to run it exclusively.

For fuel quality, I'd recommend you look into what makes "Top Tier" fuel better...and stick with filling up at those stations.

JohnD said:

I ran a tank of regular once. The difference is noticeable, not glaring but it is there. It just doesn't feel as sharp, I can't come up with a better term than that.

I get that some people maybe don't want to or simply can't afford premium, but I am fortunate enough that the cost is not an issue so I'll continue using premium.

Click to expand...

Lol, it's not about being able to afford premium...never has been. Some people just chose to spend their money a bit more wisely than others (no pun intended).

fewt said:

You own a S550 coyote, if you can't accept the data because of a minor revision change to the motor maybe you can run your car on a dyno and share?

Ford literally states that the motor makes 435HP on premium fuel. They stopped publishing what the motor makes on 87 when the 2013 landed.

Click to expand...

There are F150 coyote dynos out there showing a much smaller power loss. One of these days i'll end up putting together some data for a comparison.

And For the record, Ford actually states they recommend 87 octane fuel. I don't care about the small loss in power for my daily driver.

millhouse said:

Lol, it's not about being able to afford premium...never has been. Some people just chose to spend their money a bit more wisely than others (no pun intended).



There are F150 coyote dynos out there showing a much smaller power loss. One of these days i'll end up putting together some data for a comparison.

And For the record, Ford actually states they recommend 87 octane fuel. I don't care about the small loss in power for my daily driver.

Click to expand...

The F150 has a completely different tune, that's an apples and oranges comparison.

fewt said:

You own a S550 coyote, if you can't accept the data because of a minor revision change to the motor maybe you can run your car on a dyno and share?

Ford literally states that the motor makes 435HP on premium fuel. They stopped publishing what the motor makes on 87 when the 2013 landed.

Click to expand...

Lol, the data is there. I would love to test out millhouses theory, but i dont have a mustang. I would never put 87 octane anyways.

The thought never crossed my mind. I fill up the Viper every 2-3 days worth of driving (avg 14 mpg). Should I put 87 because the qualities are the same? :headbonk: FUCK NO!

I want race car performance at all times, on and off the track. Thank goodness none of my cars see a ton of miles, if I did I wouldnt be driving a mustang as a daily, shit got old real quick when I did.

fewt said:

The F150 has a completely different tune, that's an apples and oranges comparison.

Click to expand...

Hmm, kind of like the S550 has a completely different tune than the s197?

1mic said:

The thought never crossed my mind. I fill up the Viper every 2-3 days worth of driving (avg 14 mpg). Should I put 87 because the qualities are the same? :headbonk: FUCK NO!

Click to expand...

You obviously did not read a single word I wrote.

millhouse said:

Hmm, kind of like the S550 has a completely different tune than the s197?

Click to expand...

We should let someone who tunes this motor answer that, but we're only talking about a 23HP bump in power from the 2011 to the 2017 (premium fuel :lol. I doubt it's a completely different tune.

fewt said:

We should let someone who tunes this motor answer that, but we're only talking about a 23HP bump in power from the 2011 to the 2017 (premium fuel :lol. I doubt it's a completely different tune.

Click to expand...

Hmm, the 2018 is only getting a 25hp bump, does that mean the tune is the same?

You see my point?

We shouldn't be making any assumptions on power or performance differentials until someone has done their due diligence.

Some seem to be able to notice a difference while others don't. That's all we really have at this point.

millhouse said:

Hmm, the 2018 is only getting a 25hp bump, does that mean the tune is the same?

Click to expand...

A minor change does not mean a complete change.

millhouse said:

You see my point?

Click to expand...

Not really.

millhouse said:

We shouldn't be making any assumptions on power or performance differentials until someone has done their due diligence.

Click to expand...

It's not an assumption, it's a published Ford benchmark.

millhouse said:

Some seem to be able to notice a difference while others don't. That's all we really have at this point.

Click to expand...

There's that, and Ford's published specifications (for the 2017 below). If you never drive the car hard or above 4k rpm, you can make the case for not running 91+.





https://www.ford.com/services/assets/Brochure?make=Ford&model=Mustang&year=2017&postalCode=32817

I'm going to stop beating this dead horse though. :lol:

fewt said:

We should let someone who tunes this motor answer that, but we're only talking about a 23HP bump in power from the 2011 to the 2017 (premium fuel :lol. I doubt it's a completely different tune.

Click to expand...

Alejandro Flores, ydbt would be he guy to answer.

fewt said:

A minor change does not mean a complete change.



Not really.



It's not an assumption, it's a published Ford benchmark.



There's that, and Ford's published specifications (for the 2017 below). If you never drive the car hard or above 4k rpm, there's no reason to run 91+.

https://www.ford.com/services/assets/Brochure?make=Ford&model=Mustang&year=2017&postalCode=32817

Click to expand...

So what exactly do you gain at 3500 rpm on 93 octane in the S550? At 6500 RPM? How much does the area under the curve change? How does it affect the 1/4 mile?

All you know is, Ford uses it to get max performance. You don't know what that max performance is. You don't know how it affect performance in 95 degree weather with 95% humidity or 65 degree weather with 45% humidity.

And of course, none of this has any bearing for the 99% that daily drivers their vehicles.