Yep...got one guy on here, thinks the Eco is a Bad Motor...then there is everybody who actually drives one. We Love it.
People keep saying that the point of the Eco is better MPG. It does have better MPG, when Output is factored in, at the Same MPG as the 5.0 based on Fuelly, the Eco Boost gets 40 More LB/FT, and has more usable power, because of how flat and steady the powerband is.
We keep hearing the 5.0 is better in the long run because of maintenance, yet I have really not heard any horror stories with the 3.5 across the board. Hell even a V8 can have it's own set of issues. Let's take the 5.4 for example and it propensity to spit spark plugs...Only time will tell. So far the EcoBoost 3.5TT has a great reputation.
Turbos produce enormous amount of heat. Exhaust, direct, from the engine, spin them. Ford, GM and Chrysler sold turbo cars in the 80's. They all had good performance and turbo issues. They were phased out, why? Now Ford brings the turbo back, but call it the Eco Boost. It is the same technology. Drag racers, with turbos burn Methanol. It is easier on the turbo. Locomotives are massive, turbo diesels. They rarely get shut down. If they do, a electric oil pump, sends oil to the turbo, for 30 minutes.
Like Jeff said, lot's of FLAT UP WRONG info in this thread. If you read it on the internet, and don't actually know the science, don't repeat it.
"Better to remain silent and be thought a fool than to speak and to remove all doubt." That applies to the Forums also.
Bottom line... You can run 87. It will not hurt your 15+ Expy. You can save a little money at the Pump. If you want the best Performance, run 91+. If you don't have to pay for your own gas, definitely run 91+, why not???
Octane rating
- Thread starter The dude
- Start date
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ManUpOrShutUp
Full Access Members
This entire thread has gotten ridiculous. There are numerous sources that indicate power improvements with higher octane fuel in the EcoBoost engine. The improvements seem trivial to me, but to each his own. You will be spending more on gas than you would with the 5.4L engine as the MPG savings of the EcoBoost over the 5.4L are not nearly enough to cover the additional cost of premium gas. As for the EcoBoost vs the 5.4L on power - come on. We all know the 5.4L is a dog (at least when tasked with moving a vehicle as heavy as the Expedition). Ford really had nowhere to go but up on that front. That said, the EcoBoost does run out of steam at high RPMs.
ExpeditionAndy
Full Access Members
Funny!
Ford, GM and Chrysler all tried turbo charging in the 80's. They all phased them out. Why? Now 25+ years, Ford, comes out with the Eco-boost...a turbo, again. Ford is one of the only car maker pushing it. Why? Turbos are spun by super heated engine exhaust at thousands of RPM. Air is compressed and forced into the engine. Compressing air causes it to heat and absorb moisture(damp weather issues). The air is forced through a intercooler, to lower the temp. The increased combustion pressure, causes spark detonation( high octane gas debate) and potential head gasket failure. Constantly overheated turbos can fail. The Obama, 55mpg C.A.F.E mandate(Trump ended), pushed automakers for more fuel efficiency. Maybe Ford worked all the bugs out of turbo charging. The same company that had, V8 spark plugs ejecting and plastic intake, catastrophic failure recall, just a few years ago.
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drewactual
Full Access Members
in the 80's there weren't computer controlled ignition and fuel curve which makes boosting SO much easier (and safer).
JExpedition07
That One Member
This will no longer hold to be true for the 2018 model year, they have expanded the 6.2 to Tahoe and suburban so it will be an option in the entire suv lineup for them. Like I said haven no beef with the ecoboost I just would like to see options.
ExpeditionAndy
Full Access Members
The compression ratio in the EcoBoost engine is 10.0:1 it isn't a high compression engine. Normally you have to be above 10.5:1 to be a the low end of high compression engines.
This is from the 2017 owner's manual:
FUEL QUALITY
Choosing the Right Fuel
Your vehicle is designed to operate on
regular unleaded gasoline with a minimum
pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in
high altitude areas, offer fuels posted as
regular unleaded gasoline with an octane
rating below 87. We do not recommend
these fuels.
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. See Towing (page 202).
Do not use any fuel other than those
recommended because they could lead to
engine damage that will not be covered by
the vehicle Warranty.
Note: Use of any fuel other than those
recommended can impair the emission
control system and cause a loss of vehicle
performance.
So, according to Ford the engine was designed to operate on regular gas, not premium. It can use premium when you need more power from the engine using the computer and sensors based on the comments above.
This is from the 2017 owner's manual:
FUEL QUALITY
Choosing the Right Fuel
Your vehicle is designed to operate on
regular unleaded gasoline with a minimum
pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in
high altitude areas, offer fuels posted as
regular unleaded gasoline with an octane
rating below 87. We do not recommend
these fuels.
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. See Towing (page 202).
Do not use any fuel other than those
recommended because they could lead to
engine damage that will not be covered by
the vehicle Warranty.
Note: Use of any fuel other than those
recommended can impair the emission
control system and cause a loss of vehicle
performance.
So, according to Ford the engine was designed to operate on regular gas, not premium. It can use premium when you need more power from the engine using the computer and sensors based on the comments above.
JExpedition07
That One Member
Can't argue with the manual. As the commercials say "no one knows your Ford better than Ford" lol
Big Brian
Full Access Members
this place has a bunch of Navigators and Expys in their fleet. I see them all over town. I am sure there are others
http://www.metrocars.com/
http://www.metrocars.com/
powerboatr
Full Access Members
absolute agreed
and i really like my eco boost, like din the f150 and really like it in the expy.
drewactual
Full Access Members
... and that is the mechanical compression ratio. once valve events are factored in it will be considerably less- measured from the point in the cylinder where all valves are closed. atop that, these things are have variable camshaft timing too, no? the PCM/ECU can adjust the compression too- less dynamic compression when boosting and opportunity for knock is present (as sensed by o2/lambda).
ExpeditionAndy
Full Access Members
Actually the intake and exhaust valves are variably independently controlled based on what the computer tells them to do. I'm not sure that I said that correctly, each bank of intake valves and exhaust valves are controlled by their own cam phaser so intake and exhaust isn't slaved together.
powerboatr
Full Access Members
yep we be driving incredible computing machines
There is so much wrong with your science and understanding of physics, chemistry, and the function of a turbo charged motor that there is no way I could put it in to words to fix your logic. I need a whiteboard!
Just a simple concept, the moistness of the intake charge does not change once it enters the intake. Since no moisture can be added to the system, heating the intake charge, will not cause it to "absorb" moisture.
Another simple concept. There is no such thing as Spark Detonation. There is Detonation, and there is Pre-Ignition. Detonation is AFTER the Normal burn from the Spark, and Pre-Ignition is BEFORE. Both are without the spark plug firing.
A LOT of companies are investing in Turbo Tech. Nissan has several new small turbo motors, vw has very few NA motors left in their vehicles, even GM has jumped on board, just haven't gotten to the bigger motors, other than the Duramax.
Stay in your cave, and ignore the Tech. With computers and variable valve Turbos, it is A LOT different than 24 years ago, in addition to better oils and metals. MANY improvements.
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JExpedition07
That One Member
At this point someone should make an "explaining ecoboost technology" thread since this is what we have turned it into
Ford 3.5l ecoboost WERE having issues on damp, humid days. The motor would lose power or go into limp home mode. Owners were complaining about loss of power, at highway speeds. The 3.5ltt, was having issues with carbon build up and excessive knock and ping.. Ford is the only company putting the turbo V6, in full size trucks. The other car companies,all would sell turbos, if they had a good reputation. Turbo has been around, for 40 years. There is no special metals. The oil in the Ecoboost is the same, Ford has used for a decade. I did consider buying a new Expedition and did research on the eco boost. I will never be convinced this motor belongs in the Expedition.
Ps4acc88
Active Member
Agree with everything you said about using higher octane than required.
JExpedition07
That One Member
There are many guys with 200,000 plus miles on 150s with the ecoboost but then again get I'm not so sure how hard they worked. It is a great engine and has been proven to be since 2011 for daily drivers that haul once in a while. the water gets murky when you are hammering on it all the time for work however. As with any new engines there were kinks they had to work out and they have done well at it thus far.
Ps4acc88
Active Member
You sound like a younger me, for every issue you find on the ecoboost you will find just as many issues people have with the 5.4. For the most part the eb motor has proved to be reliable and powerful . I work next to a company who uses f150s with eb for work trucks, some of them have over 220k miles and owner said all he has done is keep up with normal maintenance.
So you are saying that Metal science has not changed in 25 years...??? Really. You really do live in a cave. The tolerances, process, and alloys have definitely improved. Not to mention, just the CAD aspect in the design phase.
You just said, the oil hasn't changed in 10 years, that still makes it 15 years newer than you self set 25 year mark. The chemistry of modern synthetics has definitely improved. The flash points are higher, and the resistance to coking.
WERE having issues...do you hear of those any more. Regardless if they had issues on damp humid days, that is tuning. THERE IS NO WAY THE AIR CAN ABSORB ANY MORE MOISTURE AFTER GOES THROUGH THE TURBO THAN WHAT IT ENTERED THE INTAKE WITH. That is assuming you aren't doing water or meth injection...
Carbon build up has ZERO to do with the turbo, and having less cylinders or displacement...Let me say that one more time, Carbon Build up has ZERO to do with the turbo, and having less cylinders or displacement. It is a VERY common occurrence on direct injection motors, because the fuel is injected directly into the cylinder, not before, like in port injection. The fuel is not there to clean the intake valve, so it builds up burnt carbon. The new 2nd gen motor fixes that partially by having both types of injection. Port injection will also help with MPG, at lower power output levels, and idle.
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