Questions about Octane on an F-150

[mikeinca]

Originally Posted by RedSHED

Yeah, one of the things I like about a diesel is it's just not frenetic.


At 3400 you ought to be pretty close to Ford's "beyond here be dragons" sign on your tach... I was intending to say that if your sweet spot for fuel economy is normally 1800 or 1900, then 2100 or 2200 when it's really hot out (uphill out of Lone Pine pulling a trailer with a tail wind kind of thing) is better than 1600, and may be better than 1800. Lots of variables

LOL, yeah. "Redline" is 4000 . Peak torque for the 2017 6.7 is 925@1800-2000RPM and peak HP is 440@2800 so there are definitely diminishing returns beyond that. I've been through Lone Pine several times; Alabama Hills is one of our favored camping spots

[KJJorgen]

I would say that you most likely do not need to use premium fuel. In the mountains at high altitudes, octaine level perform a bit better than at lower altitudes, so an octane level of 85 would probably performa at a level of about 87. I would not use premium, unless I was filling up at high altitudes with a large tank but then descending quickly to be at a much lower altitude soon.

[donohue1982]

I’ve pulled my 25’ Flying Cloud for the better part of 7 years with my F-150 eco-boost and have never found any enhanced performance running higher octane than 87. I’ve read multiple articles about how the public wastes tons of money on premium octanes either misinterpreting manufacturers guidance or just naturally believing that premium gas equals premium performance. As you said, I’ve seen 85 octane in CO sold as regular unleaded and would agree not to burn that in your F-150.

[WadeF]

I have a 2015 XLT 3.5 Ecoboost, I bought it brand new in 2015 and have only used 85 octane (I'm near Denver) since day one, even when towing, 87 if it's the lowest available. As of today I have 182,000 miles on my truck with over 30k of towing some sort of trailer. We have a 2018 25' RBT flying cloud. Only issue with the truck was a mass air flow sensor went out arount 120k. I've done plugs on the truck twice and they looked fine.

[mikeinca]

Car & Driver's dyno and instrumented track tests prove that premium fuel produces more power and better fuel mileage than regular in the EcoBoost. Those are simple facts, not hype or misinformation about using higher octane. Just as important, C&D's results are consistent with Ford's own recommendation.

So, if you're using regular in an EcoBoost, regardless of how many miles you've racked up, you're making a conscious decision to trade some power for cost savings. There's absolutely nothing wrong with that and if someone is happy with their EcoBoost's towing performance using regular then it's the right move for them. If only for the sake of accuracy, though, let's not suggest there's not a measurable difference, because there is.

[jcl]

Originally Posted by mikeinca

Car & Driver's dyno and instrumented track tests prove that premium fuel produces more power and better fuel mileage than regular in the EcoBoost. Those are simple facts, not hype or misinformation about using higher octane. Just as important, C&D's results are consistent with Ford's own recommendation.

So, if you're using regular in an EcoBoost, regardless of how many miles you've racked up, you're making a conscious decision to trade some power for cost savings. There's absolutely nothing wrong with that and if someone is happy with their EcoBoost's towing performance using regular then it's the right move for them. If only for the sake of accuracy, though, let's not suggest there's not a measurable difference, because there is.

It isn’t that black and white.

Car and Driver did a single test.

There are large differences in fuel geographically. The wide range of fuels is one of the reasons for manufacturers to spec a higher octane rating, since it will cover a higher percentage of users, but that doesn’t mean they all benefit. There are also different responses to those fuels based on engine condition, driving habits, and so on,

I know that with a non turbo 3 litre for which the manufacturer recommended premium, there was no benefit beyond using 89, in power or mileage. I used 89. The dealer took the same approach for their entire fleet.

Using less than 91 in an ecoboost may result in less hp. And if it does, it may not be perceptible to the driver. While it may also reduce fuel economy, it may not be financially advantageous to use the higher octane rating depending on the price premium, and getting more mpg while spending more per mile could be a losing strategy for many.

[mikeinca]

Originally Posted by jcl

It isn’t that black and white.

Car and Driver did a single test.

There are large differences in fuel geographically. The wide range of fuels is one of the reasons for manufacturers to spec a higher octane rating, since it will cover a higher percentage of users, but that doesn’t mean they all benefit. There are also different responses to those fuels based on engine condition, driving habits, and so on,

I know that with a non turbo 3 litre for which the manufacturer recommended premium, there was no benefit beyond using 89, in power or mileage. I used 89. The dealer took the same approach for their entire fleet.

Using less than 91 in an ecoboost may result in less hp. And if it does, it may not be perceptible to the driver. While it may also reduce fuel economy, it may not be financially advantageous to use the higher octane rating depending on the price premium, and getting more mpg while spending more per mile could be a losing strategy for many.

Yes, C&D did a single test, but it corroborates what the manufacturer recommends, and wouldn't you think that Ford did testing of their own before making that recommendation?

All the variables you mention are possibilities and of course one can invent some combination of them that might reduce the usefulness of premium. But that doesn't change the fact that, all else being equal, under similar conditions premium produces superior power.

Your point about the non-turbo 3.0L is interesting but you produce no testing data or other information. It's anecdotal. Regardless, it wasn't a turbocharged 3.5L EcoBoost engine so in any case the comparison is somewhat irrelevant.

And yes, I've said from the beginning that an individual operator may not "notice" a difference or "feel" that the improvement is "worth it" to spend the extra money. I towed a 25' Airstream with an EcoBoost and "felt" that the performance differential, especially when coupled with Ford's recommendation and things that I read about reliability issues with the EcoBoost engine, was "worth it". But that is subjective just as many of the other posts expressed in this thread on the subject have been subjective. For the sake of people who are trying to make a decision based on facts and data I think it's important that they are presented.

[suncoasteng]

Originally Posted by jcl

The only reason to purchase a higher octane fuel is if the lower octane fuel does result in engine damage. With modern engine management systems that isn't the same issue it was years ago.

The history of promoting premium fuel is that the oil companies convinced the public that higher octane fuel was somehow a good thing. People use phrases such as "treating the vehicle to premium" as it there is value in that. There usually isn't. People have been conditioned by years of advertising to purchase higher grade fuel than they need, with campaigns like "put a tiger in your tank", in that case for Esso Extra. It results in people being made to feel guilty for using a perfectly adequate fuel.

there is a reason light aircraft engines, high performance marine engines and race cars use higher octane fuel. And it is not marketing. Suggest the low octane advocates participate in tear down inspection of internal combustion components to view carbon build up. But if you feel that towing a RV requires no increased performance from your engine, save a few bucks.

[DCPAS]

Originally Posted by mikeinca

Car & Driver's dyno and instrumented track tests prove that premium fuel produces more power and better fuel mileage than regular in the EcoBoost.

C&D tested the high output version of the 3.5 EcoBoost in the F-150 Limited. 450hp and 510 ft. lbs. on premium fuel. It's not the common 3.5 EcoBoost. It has higher boost and tuning to take advantage of premium fuel. The regular engine might benefit a bit from use of premium, but what the C&D article really shows was that if you run this particular engine designed to run on premium on regular fuel, you will lose a meaningful amount of power. The reverse in not true.

[jcl]

Originally Posted by suncoasteng

there is a reason light aircraft engines, high performance marine engines and race cars use higher octane fuel. And it is not marketing. Suggest the low octane advocates participate in tear down inspection of internal combustion components to view carbon build up. But if you feel that towing a RV requires no increased performance from your engine, save a few bucks.

The engines you refer to were generally designed to run on higher octane rated fuel. The engine in question here was designed to run on 87 octane rated fuel according to the manufacturer. In this example, 87 AKI isn't low octane as you describe it. It is the design octane rating. 85 would be low octane. Don't do that.

Fully agree with using high quality fuel; the error often made is in relating fuel AKI to fuel quality.

The fuel industry's marketing pitch for many years was to sell the idea that higher octane fuel was of higher quality. When higher AKI fuels had more detergents, as one example, that could be true. If the higher octane fuel has more ethanol, I suggest that it is in fact lower quality.

I am familiar with carbon buildup, both in earlier generation vehicles and in more recent direct injection engines. I don't relate AKI to those issues; I do relate fuel quality to them, but much more often to driving habits involving lots of short trips and the engines never fully warming up.

If the vehicle operator has an engine that can take advantage of higher octane ratings, and that operator can notice a performance difference on 92 over 89 or 87, whether towing or not, great. They can decide. It isn't like they are going to hurt the engine. If they can't notice a performance difference, but can calculate a fuel mileage difference, then it is a simple task to calculate the $/mile and decide if the improved fuel mileage is enough to offset the higher cost per gallon.

If the operator can not detect a performance or mileage difference, they could go to a gas station and insist on paying the price per gallon of the premium, for a tank of regular. In this example, that produces the same result as putting a tank of premium in, including lightening of the wallet.

[jcl]

Originally Posted by DCPAS

C&D tested the high output version of the 3.5 EcoBoost in the F-150 Limited. 450hp and 510 ft. lbs. on premium fuel. It's not the common 3.5 EcoBoost. It has higher boost and tuning to take advantage of premium fuel. The regular engine might benefit a bit from use of premium, but what the C&D article really shows was that if you run this particular engine designed to run on premium on regular fuel, you will lose a meaningful amount of power. The reverse in not true.

I saw that but didn't bring it up. I didn't want to be accused of flogging a dead horse. Thanks for this.

[mikeinca]

Originally Posted by DCPAS

C&D tested the high output version of the 3.5 EcoBoost in the F-150 Limited. 450hp and 510 ft. lbs. on premium fuel. It's not the common 3.5 EcoBoost. It has higher boost and tuning to take advantage of premium fuel. The regular engine might benefit a bit from use of premium, but what the C&D article really shows was that if you run this particular engine designed to run on premium on regular fuel, you will lose a meaningful amount of power. The reverse in not true.

Originally Posted by jcl

I saw that but didn't bring it up. I didn't want to be accused of flogging a dead horse. Thanks for this.

I believe you have misinterpreted which engine was being tested.

There are 3 versions of the 3.5L EcoBoost. The "basic" version with 400hp and 500lb/ft of torque is standard on Limited and Platinum models and optional on others. There's also a full hybrid version which is optional across all trim levels. Finally, there is the High Output version you refer to, which is standard only on the Raptor and not available on any other model.

C&D could have been more precise in their wording, but the "high output" 3.5L (not High Output) referenced by C&D is a generic description, not a specific Ford engine designation. This is obvious from the picture of the F150 on the dyno which is clearly not a Raptor. It's also obvious from the fact that the 450HP Raptor engine would almost certainly produce more than 360-380HP at the rear wheels.

Again, C&D's test shows that the standard 3.5L EcoBoost produces more power on premium than on regular.

[jcl]

Originally Posted by mikeinca

I believe you have misinterpreted which engine was being tested.

There are 3 versions of the 3.5L EcoBoost. The "basic" version with 400hp and 500lb/ft of torque is standard on Limited and Platinum models and optional on others. There's also a full hybrid version which is optional across all trim levels. Finally, there is the High Output version you refer to, which is standard only on the Raptor and not available on any other model.

C&D could have been more precise in their wording, but the "high output" 3.5L (not High Output) referenced by C&D is a generic description, not a specific Ford engine designation. This is obvious from the picture of the F150 on the dyno which is clearly not a Raptor. It's also obvious from the fact that the 450HP Raptor engine would almost certainly produce more than 360-380HP at the rear wheels.

Again, C&D's test shows that the standard 3.5L EcoBoost produces more power on premium than on regular.

There are a lot more than 3 versions of the EcoBoost All with different tuning. I like the one in the GT40 myself.

I saw the HO designation, but was going by the article's reference to 450 hp (128.7 hp/litre x 3.5 litres). If they don't know the flywheel hp, I have less confidence in their test results.

[mikeinca]

Originally Posted by jcl

The engine in question here was designed to run on 87 octane rated fuel according to the manufacturer. In this example, 87 AKI isn't low octane as you describe it. It is the design octane rating. 85 would be low octane. Don't do that.

Here's what I don't think one should do. I don't think one should look at the information in the manual on the type of fuel to use in a Ford 3.5L EcoBoost and selectively ignore half of it.

We can get all twisted around the axle over the use of the words designed and recommended, but a fair reading of what Ford is saying is that the EcoBoost will run fine on 87 but that when towing or under high temperatures it is suggested to use 91 octane. It's really quite straightforward and objective. The economics and personal preferences related to that choice are more subjective, and an entirely different issue.

[Daquenzer]

I looked at that article and I would concur that the F150 with a standard Ecoboost did get better mileage and power with Premium. 17.5 mpg vs. 17 mpg and about half a second faster in the 1/4 mile. The question is necessity. And that I think will depend upon towing condition, preferences, and budget.

It would be interesting to see a similar test with mid-grade and premium to compare. I have used mid-grade before, and it's only about 20 cents more per gallon.

[mikeinca]

Originally Posted by jcl

There are a lot more than 3 versions of the EcoBoost All with different tuning. I like the one in the GT40 myself.

I saw the HO designation, but was going by the article's reference to 450 hp (128.7 hp/litre x 3.5 litres). If they don't know the flywheel hp, I have less confidence in their test results.

Well, that's one more version of the 3.5L EcoBoost engine that is available in production models but since only the 3 versions I mentioned can be had in the F150, the GT40 and all other possible variants are irrelevant anyway.

The reference to 128.7 hp/litre is indeed an editorial error since the 450 HP motor isn't available in the F150 model C&D tested. If that mistake reduces your confidence in the entire test, I can't help you with that.

[jcl]

Originally Posted by mikeinca

The reference to 128.7 hp/litre is indeed an editorial error since the 450 HP motor isn't available in the F150 model C&D tested. If that mistake reduces your confidence in the entire test, I can't help you with that.

The 450 hp (Raptor) engine was available in F150s other than the Raptor when C&D did this test in 2019 (and it was also available in 2020)

[mikeinca]

Originally Posted by jcl

The 450 hp (Raptor) engine was available in F150s other than the Raptor when C&D did this test in 2019 (and it was also available in 2020)

Thank you for the information. Apparently, Ford made changes to engine availability over the years and so the C&D test turns out to have less specific relevance to the conversation, but it was only a supporting data point anyway. The most important factor, AFAIC, has always been what the owner's manual said on the subject. It's the owner's choice to ignore that; personally, I wouldn't.

[DCPAS]

Originally Posted by mikeinca

The reference to 128.7 hp/litre is indeed an editorial error since the 450 HP motor isn't available in the F150 model C&D tested.

That engine is standard in the F-150 Limited. They didn't mention the model, but is obviously isn't the Raptor, so it is the Limited.

[mikeinca]

Originally Posted by DCPAS

That engine is standard in the F-150 Limited. They didn't mention the model, but is obviously isn't the Raptor, so it is the Limited.

The grill confirms that it's a Limited and while the HO 3.5L apparently was standard in that model at the time of the C&D test, it is no longer. Anyway, I stand corrected on that point.