Car and Driver octane test

P 4 and still on the "may" vs "shall" and "reccomended" vs "required" thing.....
Stands to reason, as many people do not understand the significance of these words in the context in which they're used sometimes.
Free advice to those people, learn this, it's an important life hack to know when you "have" to do something or when you don't "have" to. Not just as it pertains to inane octane discussions.

womps wrote:

Copperhead wrote:

Groover wrote:

Bionic Man wrote:
So, did Ford change their recommendation in the owners manual away from premium fuel?

Ford has never recommended premium for the base model Ecoboost engines engines but they have for the high output engines in the Raptor, Limited and Lincoln.

So have they changed, NO. Do they have various recommendations, YES.

See the bottom of the first page in the attachment. Standard Ecoboost on the left, HO version on the right:

2019 F150 specs

Didi you happen to notice that link also shows a recommendation of ULSD up to B20 for the EB 2.7? That one is new to me. The EB 2.7 is a diesel engine? Yet in the same column on that motor, it says it is coil over plug design. A diesel with spark plugs? So it makes the entire specs sheet seem suspect regarding fuel recommendation. Also, it shows the 5.0L as a 12:1 compression ratio. The 5.0 has never been a high compression engine.

Whomever put that sheet together had no clue what they were doing.

What spec sheet are you reading? No where do I read that the 2.7 is a Diesel engine. The 5.0 Coyote V8 does have a 12:1 compression ratio. This information is from the Ford website.

My bad. I read too far down the sheet under the column for the 2.7 and didn't realize I was looking at 3.0 diesel info. Also, the 5.0 Coyote in the F150 has a lower compression ratio of 10.5:1. From a wiki on the subject....

A torque-biased variant of the Coyote is produced as an alternative to the EcoBoost V6 in the new F-150 pickup truck. The F150 5.0L receives a lower compression ratio (10.5:1), intake camshafts with less duration, cast iron exhaust manifolds, and revised cylinder heads

Copperhead wrote:

Groover wrote:

Bionic Man wrote:
So, did Ford change their recommendation in the owners manual away from premium fuel?

Ford has never recommended premium for the base model Ecoboost engines engines but they have for the high output engines in the Raptor, Limited and Lincoln.

So have they changed, NO. Do they have various recommendations, YES.

See the bottom of the first page in the attachment. Standard Ecoboost on the left, HO version on the right:

2019 F150 specs

Didi you happen to notice that link also shows a recommendation of ULSD up to B20 for the EB 2.7? That one is new to me. The EB 2.7 is a diesel engine? Yet in the same column on that motor, it says it is coil over plug design. A diesel with spark plugs? So it makes the entire specs sheet seem suspect regarding fuel recommendation. Also, it shows the 5.0L as a 12:1 compression ratio. The 5.0 has never been a high compression engine.

Whomever put that sheet together had no clue what they were doing.

What spec sheet are you reading? No where do I read that the 2.7 is a Diesel engine. The 5.0 Coyote V8 does have a 12:1 compression ratio. This information is from the Ford website.

Groover wrote:

Bionic Man wrote:
So, did Ford change their recommendation in the owners manual away from premium fuel?

Ford has never recommended premium for the base model Ecoboost engines engines but they have for the high output engines in the Raptor, Limited and Lincoln.

So have they changed, NO. Do they have various recommendations, YES.

See the bottom of the first page in the attachment. Standard Ecoboost on the left, HO version on the right:

2019 F150 specs

Didi you happen to notice that link also shows a recommendation of ULSD up to B20 for the EB 2.7? That one is new to me. The EB 2.7 is a diesel engine? Yet in the same column on that motor, it says it is coil over plug design. A diesel with spark plugs? So it makes the entire specs sheet seem suspect regarding fuel recommendation. Also, it shows the 5.0L as a 12:1 compression ratio. The 5.0 has never been a high compression engine.

Whomever put that sheet together had no clue what they were doing.

Torque is more immediate and performance better across the band with higher octane fuels,dependent on turbo design and its lag.
(3 octane is not for top end wot performance but allows increased timing advance and torque from bottom to top of the throttle.
Only problem is the cost of 93 octane or 87 octane and octane booster.
There is no gain in power without increase fuel. Unless we get into Adiabatic engines with or without turbos and much higher temps and effeciency, at greatly increased cost, of course.Burnign lots fo lower octane fuel leads to detonation. The engine software ******* the timing and opens the bypass valve sooner,so it doesn't detonate but operates at less power. If you have enough power to get you up the hill fine, but it will use more fuel than higher octane and may still overheat. Heavy enough and it will still detonate.Savings using 87 octane over 93 octane current prices, I have no idea. I'm sure the mfg has tables but perhaps not published.

Somehow that manual page forgot to mention that E85 has an octane rating of 100. I have used E85 frequently over the years, and exclusively for the last two years. My 2015 Chevy 2500 runs very well on E85, and my wife 2017 Equinox with the 11.2:1 ratio 2.4 motor really runs great on E85. And even with the lower fuel economy of E85, it is averaging about $.90 to $1 less than premium. And the actual real world MPG results show, on a fuel cost per mile basis, E85 is very competitive to Premium fuel in terms of actual cost per mile and how it performs. Far fewer combustion deposits with E85 and injectors stay cleaner. The air going in to the combustion chamber is more dense because ethanol has a great cooling effect on the air. The air is cooler in the combustion chamber on compression stroke and E85 has a far higher oxygen content in the fuel so these thing lead to a more uniform and complete burn. Talk to the racing and high performance community. Many of them use E85.

Here is from the 2018 Superduty owners manual for the 6.2L engine.


2018 SUPER DUTY Owner’s Manual




Ford states the same thing for all of their engines(Ecoboost or not) that can adjust their power level to the octane being used even though they are designed to run on 87. The reason why you probably never seen this before is because not all engines can do this and running 91 octane fuel does nothing in regards to performance.

Lynnmor wrote:

Groover wrote:
Recommend and Require have quite different meanings, please learn and understand them.

Again & again, here is the owners manual:

For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer.

I don't care if you run skunk pee, but you don't need to talk down to someone that only displays information from Ford.

What part of this do you not understand?

Again and again,


I can cherry pick and leave out other information too.....

F150 3.5 Ecoboost owners manual

"Your vehicle is designed to operate on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87."


Simply put, the Ecoboost is designed to run on regular fuel meaning its hard parts and cam profile is specifically designed to use 87 octane unloaded or at max capacity. However, since it is a multi-octane engine that can adjust its valve, ignition, and fuel timing, it can utilize the added power benefits of premium fuel which will only be noticeable in certain high load situations. You don't have to run premium at any time, but you can IF you want to. Older engines with fixed valve, ignition, and fuel timing were not able to adjust for higher octane fuel so running premium did nothing.

Ford 5.0L and 6.2L engines are also multi-octane engines and will also increase output with premium fuel even though they are designed to run on regular. Their owners manual say the very same thing as the Ecoboost owners manual.

What part of this do you not understand?

Groover wrote:
Recommend and Require have quite different meanings, please learn and understand them.

Again & again, here is the owners manual:

For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather as well as other conditions, for example when towing a trailer.

I don't care if you run skunk pee, but you don't need to talk down to someone that only displays information from Ford.

What part of this do you not understand?

Lynnmor wrote:

ShinerBock wrote:

Lynnmor wrote:


Sad that folks need to resort to personal attacks because they can't even read an owners manual.

We can read it just fine, you just interpret what it states differently than what normal people do. You think it means that you have to run premium when towing, and we know it means that it is a recommendation if you want max power output which will be more noticable in situations such as towing, but it is not required in order to tow.

I didn't "interpret" anything, I simply displayed the owners manual for those that will not otherwise read it. This is the TOWING section of an RV FORUM and some may want to educate themselves, a few apparently want to only make childish remarks.

I don't care what fuel you put in your vehicle and wish that you didn't care what I put in mine. Especially since you apparently have no relevant personal experience and with my two Ecoboost trucks combined I have nine years and 150,000 miles of experience. If you want to buy an Ecoboost and put premium in it I won't criticize your choice and will sincerely hope that whatever you do works out well for you.

But, from the link I posted earlier you can see clearly see that while Ford does require premium in the HO engines they only require regular in the vast majority of the Ecoboost engines they build, including the two that I own and use. Recommend and Require have quite different meanings, please learn and understand them.

re·quire
specify as compulsory.
"the minimum car insurance required by law"

rec·om·mend
/?rek??mend/

1.put forward (someone or something) with approval as being suitable for a particular purpose or role.