What Fuel Do You Use in Your EcoBoost?

[BurbMan]

So last year we got a 2018 Explorer Sport with the 3.5L EcoBoost, the same motor they put in the F-150's that a lot of guys tow with. (The Explorer is not on towing duty, we still have the Suburban for that.)

The owner's manual says to use whatever octane of fuel you want, but that the engine will perform better on hi-test. We've been putting only 93 in the tank and it runs great!

This month Car and Driver runs an article about "Are you wasting money on hi-test" and it looks at 4 examples of vehicles, one of which was the F-150 with the 3.5L EB. Apparently the PCM uses the knock sensors to "measure" the octane of the fuel...the PCM advances timing until it detects knock, then backs it down until no knock is detected.

The results of the C&D test were that the EB was the only engine tested to significantly benefit from the higher octane fuel, as measured by +20 hp, +1.5 psi boost, and -0.5 sec in the 1/4 mile. Fuel economy at highway speeds was also 0.5 mpg better, although it was noted that this in no way makes running 93 an economical option. It costs more to run 93 no matter how you slice it.

C&D also noted that the truck ran fine on 87, no knocking, hesitation, or other symptoms of poor performance, but it felt slower in daily driving.

I'm curious if you guys that run F-150's are using hi-test, and if not I would suggest you give it a try.

[philh]

johndeerefarmer wrote:
I run 93 octane when towing or if it's hot outside. Ford has said that you get an extra 10HP/10 Lb ft when running premium

10 hp is meaningless. The only time you would even see that is during wide open throttle operations, which is like never.

[johndeerefarmer]

BurbMan wrote:
So last year we got a 2018 Explorer Sport with the 3.5L EcoBoost, the same motor they put in the F-150's that a lot of guys tow with. (The Explorer is not on towing duty, we still have the Suburban for that.)

The owner's manual says to use whatever octane of fuel you want, but that the engine will perform better on hi-test. We've been putting only 93 in the tank and it runs great!

This month Car and Driver runs an article about "Are you wasting money on hi-test" and it looks at 4 examples of vehicles, one of which was the F-150 with the 3.5L EB. Apparently the PCM uses the knock sensors to "measure" the octane of the fuel...the PCM advances timing until it detects knock, then backs it down until no knock is detected.

The results of the C&D test were that the EB was the only engine tested to significantly benefit from the higher octane fuel, as measured by +20 hp, +1.5 psi boost, and -0.5 sec in the 1/4 mile. Fuel economy at highway speeds was also 0.5 mpg better, although it was noted that this in no way makes running 93 an economical option. It costs more to run 93 no matter how you slice it.

C&D also noted that the truck ran fine on 87, no knocking, hesitation, or other symptoms of poor performance, but it felt slower in daily driving.

I'm curious if you guys that run F-150's are using hi-test, and if not I would suggest you give it a try.

I run 93 octane when towing or if it's hot outside. Ford has said that you get an extra 10HP/10 Lb ft when running premium

[JAC1982]

So as you can see from my signature we have a collection of Fords, two of which are the 3.5EBs.

The Explorer is my daily driver with around 40,000 miles on it and I run premium in it all the time (91 here in CO). I have a fairly lengthy commute that is about 50/50 in terms of lower speed highway (50-60mph) and city driving and I find it runs better if I stick to premium. I don't pay much attention to gas mileage, but more just how it "feels". I average around 20mpg though and have a lead foot FWIW 🙂

My husband runs mid-grade in his F-150 with similar mileage and says he doesn't really notice a difference, but he also only uses his truck for quick trips around town (he works from home).

[lenr]

When Ford first put the EB 3.5 in the F 150, they lowered the compression ratio from the auto version to avoid pinging while towing. Of course the other way to do it is higher octane fuel. Very interesting that octane is well established as not worth the cost.

[NWnative]

Do what your manual recommends....why question it? I ran 92 in my 3.5EB when I had it and I run 92 in my 6.2 which carries the same recommendation in the manual. I tow with it 70% of the time. There is no benefit to Ford for recommending something that will cost the consumer more money (and that the other guys don't recommend) unless there is a valid reason to do so (best performance when towing or in hot climates). It should also be noted that all of the HP/ TQ claims in the small print in their advertising specifically mentions 'premium fuel' was used.

[KrowNB]

I have a 2016 F-150 Eco-Boost. In 2017 I carefully monitored my fuel consumption over numerous tanks of 87 and then 91 octane and recorded fuel consumption both towing (30 ft TT)and not using an app (aCar). I can't remember the exact data but I was able to determine that there was a definite improvement in consumption using 91. I then compared to increase in cost (expensive fuel here in Canada) and calculated that there was little difference in subsequent cost with maybe a slight advantage to the hi-test. As a result, I've only used 91 in my truck since. Of course, if my driving habits were different, the results may be different. I'm pretty light on acceleration and tend to slow gradually rather than brake hard.

[BarabooBob]

I use regular (87 octane, 10% ethanol) in my F150 towing a 3500 pound trailer. I have not had any problems. I tried 3 tanks of 91 octane while towing and noticed a slight increase in mpg but not enough to spend the extra $$ on premium gas.
While towing through the Rockies in Sept, I will continue to use 87 octane even though many stations sell 85 octane as regular due to the higher elevations. My EB does not care about elevation changes because the boost thinks it is at sea level.

[theoldwizard1]

I run premium in my old E150 when towing, especially through the mountains.

[twodownzero]

I would not put regular unleaded in any vehicle that says "Premium fuel recommended." Especially under boost, the engine will be destroyed if the knock sensor doesn't work correctly. Modern engines are on the ragged edge of pinging as it is and expensive to repair or replace. Besides the reduced performance, that is a risk I wouldn't take.

[BurbMan]

Campfire Time wrote:
Comparing an Explorer to an F-150 is not apples to apples.

Absolutely true, but with the same engine in both there should be some correlation in results. I was more intrigued at how far the tech has advanced to where the PCM can tune the truck on the fly based on what gas you put in it. Also somewhat surprised that C&D testing showed as big of a difference as it did.

As you said, YMMV and certainly not recommending everyone run 93, just sharing what I found out.

[Campfire_Time]

This is a case of YMMV. Everyone's driving styles are different.

Over the years I've owned several "premium optional" vehicles. One of them got the same mileage and performance on mid-grade (89) as on premium, but far better performance than regular (87). Mileage was the same with any of them. At the time mid-grade was only 10¢ more so it was worth it.

Another car got better mileage with premium. At the time gas was $4 a gallon and premium was 20¢ more than regular. Doing the math I saved about $200 a year using premium. Now premium is 40¢-60¢ a gallon more and gas is far cheaper. I no longer use premium in that car.

That said you have to test it yourself. Comparing and Explorer to an F-150 is not apples to apples. I suggest running two tanks of regular. Carefully record the mileage. Take note of acceleration and passing ability on the freeway. Run the second tank close to empty. Run 2 tanks of premium and record the same observations. Then you'll be able to better decide what's going to work for you.

[BB_TX]

Our 2015 Expedition with the 3.5 EB has plenty of power running 87 octane. Not going to spend that much extra for fuel when I don't need to, simply because it "feels better".

[AlwaysOnTheRoad]

I've got 89K miles of towing and daily driving on my 2016 2.7 EcoBoost F150.
I have run both 93 and 89 octane when towing and I can't tell a difference. When not towing, I get over 20mpg on 87 octane and only a tad more mpg if running a higher octane.

[carringb]

My sister also has an Explorer Sport, with almost 70,000 miles. She runs premium too.She tows occasionally (17' ski boat) but mostly she likes the better performance. There is a noticeable reduction in throttle response lag, especially in warmer weather.

I've pretty much found the same in my Focus EcoBoost.Fuel economy benefit is there but slight (about 3 MPG in mountain driving, not much different in town), but also a noticeable performance benefit. In hot weather, it noticeably pulls timing at low and mid RPMs at WOT. Plus I tow a utility trailer on occasion as well, and the Focus EcoBoost requires Premium when towing. It's not just recommended like the 3.5L.