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06-30-2019, 02:26 PM
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#21
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Senior Member
Join Date: Feb 2016
Location: Naugatuck, Connecticut
Trailer: 2017 50 TA, 2016 F150, 2.7 Ecoboost
Posts: 1,056
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Quote:
Originally Posted by Ron in BC
Me too but sometimes I'm not all the comfortable with the higher revs. A few times I've gone to manual mode and kicked it up a gear. Sort of a compromise.
Ron
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Just use the brakes, and as far as the revs, the engine management won't let it blow up. Providing your not running some aftermarket tuner.i don't care how big the motor, on a steep enough down grade you have to bring the brakes into play. Where that not the case we wouldn't need those truck run off ramps now would we?
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06-30-2019, 02:31 PM
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#22
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Senior Member
Join Date: Oct 2008
Location: Calgary, Alberta
Trailer: 2017 Escape 5.0 TA
Posts: 15,532
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I too was a bit concerned with the higher revs of my 3.5L EcoBoost on steeper downhills, but as long as it was staying down at the desired speed I did not worry about it. I asked at Ford service and they said it was fine and if needed it would go up a gear and to brake on real steep slopes.
My Super Duties too had the Tow/Haul mode, and did rev a lot lower but they were diesel Power Strokes so never revved up as high as the smaller gas engine.
__________________
2017 Escape 5.0 TA
2015 Ford F150 Lariat 3.5L EcoBoost
2009 Escape 19 (previous)
“Most folks are about as happy as they make up their minds to be.” — Abraham Lincoln
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06-30-2019, 02:37 PM
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#23
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Senior Member
Join Date: Feb 2016
Location: Naugatuck, Connecticut
Trailer: 2017 50 TA, 2016 F150, 2.7 Ecoboost
Posts: 1,056
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Quote:
Originally Posted by Defenestrator
It's a heat dissipation issue in this case. Turbos lose significantly less power at altitude compared to normally aspirated, yes, but they lose just as much cooling capacity. It can also be a problem for the transmission. Turbos actually exacerbate this somewhat by feeding warmer air into the engine. It seems to be a reasonably common issue with the 3.5EB when towing large amounts up extended grades on hot days.
Either way, probably not a problem for anything Escape-sized, though. The problems seem to be more in the 6-8Klb range rather than the 3.5K-5Klb
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As long as the radiator, coolers, and engine management systems have been properly engineered the benefits of the turbo can be fully exploited. Some of the most successful aircraft engines in history have been either turbocharged or supercharged.
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06-30-2019, 10:18 PM
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#24
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Senior Member
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 14,935
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Quote:
Originally Posted by huskersteffy
Maybe all modern trucks with tow package do this, but I love how the transmission shifts into a lower gear on downgrades so you arte not riding the brakes.
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Yes, that should be expected in any modern vehicle; even my 2004 minivan (which has the same transmission control with or without tow package) does it.
I agree, it's a great feature.
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06-30-2019, 10:26 PM
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#25
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Senior Member
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 14,935
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A turbocharger enables an engine to deliver the power of a larger non-turbocharged engine, but doesn't add any engine braking (which is a function of displacement and speed, with a small effect of valve overlap). That means the EcoBoost 2.7 and 3.5 pull as well as the 5.4 L V8, but need to spin faster to brake enough on descents. The engine braking available at high (but still safe) engine speed is substantial, so I suspect that as long as the transmission has closely spaced enough gear ratios to hit the right engine speed (so the 10 speed is fine but the 6 speed might not be), the only issue is likely driver comfort with the required speed, not effectiveness or reliability.
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06-30-2019, 10:51 PM
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#26
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Senior Member
Join Date: Sep 2013
Location: SLO County, California
Trailer: 2014 Escape 21C 2019 Expedition
Posts: 5,210
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A turbo motor may add engine braking, just not as much as a same displacement normally aspirated engine as it has a lower compression ratio. Then besides that some engines have variable valve timing engineered for grade braking and fuel efficiency while others do not.
__________________
"We gotta get as far away as we can!"
- Russell Casse, Independence Day
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07-01-2019, 01:19 AM
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#27
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Senior Member
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 14,935
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Quote:
Originally Posted by Rossue
A turbo motor may add engine braking, just not as much as a same displacement normally aspirated engine as it has a lower compression ratio. Then besides that some engines have variable valve timing engineered for grade braking and fuel efficiency while others do not.
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A turbo engine has engine braking, but the turbo doesn't improve it meaningfully because the turbo doesn't greatly obstruct airflow (although with variable vanes the turbine can be useful).
The compression ratio doesn't matter because these are not heavy diesels with compression-release (Jacobs) brakes. Higher compression ratio takes more energy on the compression stroke, but gives it back on the power stroke which follows. Engine braking in gasoline engines is just the result of pulling air past the closed throttle valve.
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07-01-2019, 05:21 PM
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#28
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Senior Member
Join Date: Feb 2016
Location: Naugatuck, Connecticut
Trailer: 2017 50 TA, 2016 F150, 2.7 Ecoboost
Posts: 1,056
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Quote:
Originally Posted by Rossue
A turbo motor may add engine braking, just not as much as a same displacement normally aspirated engine as it has a lower compression ratio. Then besides that some engines have variable valve timing engineered for grade braking and fuel efficiency while others do not.
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Variable cam timing has become the norm for modern engines. The EcoBoost engines and the v8 are equipped with it. As to the compression on the EcoBoost, my 2.7 has 10:1. This is by no means low. The 5 liter v8 is at 10.5:1. Now if you where adding a turbo or supercharger to a normally aspirated motor you would probably put low compression pistons in to prevent rod or bearing failure. When the motor is designed from day 1 as a boosted motor it can be built to handle the higher pressures, just as diesel motors are.😁
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07-01-2019, 06:12 PM
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#29
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Senior Member
Join Date: Sep 2013
Location: SLO County, California
Trailer: 2014 Escape 21C 2019 Expedition
Posts: 5,210
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Quote:
Originally Posted by Ron in BC
Me too but sometimes I'm not all the comfortable with the higher revs.
Ron
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First time mine did it I thought something happened to the motor. Now when I am approaching a summit that says 6% grade next six miles(or whatever) I will slow down to 45 and set the cruise control. As soon as it hits 50 the engine braking kicks in. Then if I do use the brakes the engine braking is still also working even though the cruise control is off until I let the speed go to 55.
Although it will also go into braking mode on it's own I've found I can control it better and use the brakes a lot less going down those longer grades.
__________________
"We gotta get as far away as we can!"
- Russell Casse, Independence Day
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07-01-2019, 07:00 PM
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#30
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Senior Member
Join Date: Dec 2012
Location: Edmonton, Alberta
Trailer: 1979 Boler B1700
Posts: 14,935
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Quote:
Originally Posted by Chotch
When the motor is designed from day 1 as a boosted motor it can be built to handle the higher pressures, just as diesel motors are.😁
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True... and the feature which enables high compression ratio without preignition (knock) despite turbo boost is direct fuel injection. Before direct injection, turbocharged gasoline engines had significantly lower compression ratio than related non-turbo engines, even if factory-built for the turbo application. That's the defining characteristic of the EcoBoost engines - they are all direct-injection turbos, as are similar modern turbo gas engines from other manufacturers.
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07-01-2019, 07:43 PM
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#31
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Senior Member
Join Date: Aug 2015
Location: Frewsburg, New York
Trailer: 2017 Escape 21, pulled by 2018 F150 EcoBoost
Posts: 158
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We just pulled Route 191 from Vernal, Utah North to Dutch John (Flaming Gorge). 2018 Ford F150 Crew Cab with 3.5L EcoBoost and tow package pulling a 2Gen 21. 3,00 feet elevation change over four miles uphill with 8% - 10% grades. multiple down hills at 8% grade. Towing capability is impressive. 13 mpg today over 400 miles. Braking on the steep downhills feels absolutely safe. We run in Tow Mode when pulling the trailer. The Truck & Trailer held 45 mph downhill even on the steepest grades.
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07-01-2019, 08:23 PM
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#32
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Senior Member
Join Date: Feb 2016
Location: Naugatuck, Connecticut
Trailer: 2017 50 TA, 2016 F150, 2.7 Ecoboost
Posts: 1,056
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Quote:
Originally Posted by pstyer
We just pulled Route 191 from Vernal, Utah North to Dutch John (Flaming Gorge). 2018 Ford F150 Crew Cab with 3.5L EcoBoost and tow package pulling a 2Gen 21. 3,00 feet elevation change over four miles uphill with 8% - 10% grades. multiple down hills at 8% grade. Towing capability is impressive. 13 mpg today over 400 miles. Braking on the steep downhills feels absolutely safe. We run in Tow Mode when pulling the trailer. The Truck & Trailer held 45 mph downhill even on the steepest grades.
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👍👍 What's not to like 😎
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07-01-2019, 10:19 PM
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#33
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Senior Member
Join Date: Feb 2013
Location: Santa Rosa County, Florida
Trailer: 2014 Escape 21 Tow: 2024 Toyota Tundra
Posts: 3,097
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Quote:
Originally Posted by Brian B-P
True... and the feature which enables high compression ratio without preignition (knock) despite turbo boost is direct fuel injection.
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Hmm.. Do the Eco-Boost engines require premium gas? I'm guessing not, but I'd like to know.
__________________
Mike Lewis
She don't lie, she don't lie, she don't lie-- propane
Photos and travelogues here: mikelewisimages.com
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07-01-2019, 10:27 PM
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#34
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Senior Member
Join Date: Oct 2008
Location: Calgary, Alberta
Trailer: 2017 Escape 5.0 TA
Posts: 15,532
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Just regular.
__________________
2017 Escape 5.0 TA
2015 Ford F150 Lariat 3.5L EcoBoost
2009 Escape 19 (previous)
“Most folks are about as happy as they make up their minds to be.” — Abraham Lincoln
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07-02-2019, 06:56 AM
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#35
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Senior Member
Join Date: Feb 2016
Location: Naugatuck, Connecticut
Trailer: 2017 50 TA, 2016 F150, 2.7 Ecoboost
Posts: 1,056
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The EcoBoost run fine on regular, you can use high octane and realize a gain in performance. When I'm towing in mountainous areas I use the midrange, 89 octane or high test if that's not available. This is suggested in the manual. 😎
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07-02-2019, 07:05 AM
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#36
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Senior Member
Join Date: Jun 2010
Location: Central, Pennsylvania
Trailer: Escape#5 2022 E19
Posts: 26,268
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I always use mid range in my v-8 and when in the corn states area with the 10% additive I use high test to get me out of the area.
__________________
Jim
Sometime life gets in the way of living.......
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07-02-2019, 09:53 AM
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#37
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Senior Member
Join Date: Aug 2016
Location: WI, Wisconsin
Trailer: 2018 Escape 5.0 TA
Posts: 465
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Quote:
Originally Posted by pstyer
We just pulled Route 191 from Vernal, Utah North to Dutch John (Flaming Gorge). 2018 Ford F150 Crew Cab with 3.5L EcoBoost and tow package pulling a 2Gen 21. 3,00 feet elevation change over four miles uphill with 8% - 10% grades. multiple down hills at 8% grade. Towing capability is impressive. 13 mpg today over 400 miles. Braking on the steep downhills feels absolutely safe. We run in Tow Mode when pulling the trailer. The Truck & Trailer held 45 mph downhill even on the steepest grades.
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Can you clarify if the tow mode by itself was maintaining the 45 mph speed or if you were also braking? I asked because you mention braking.
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07-02-2019, 09:55 AM
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#38
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Senior Member
Join Date: Aug 2016
Location: WI, Wisconsin
Trailer: 2018 Escape 5.0 TA
Posts: 465
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Quote:
Originally Posted by Chotch
The EcoBoost run fine on regular, you can use high octane and realize a gain in performance. When I'm towing in mountainous areas I use the midrange, 89 octane or high test if that's not available. This is suggested in the manual. 😎
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In my small test sample so far our 2018 3.5 gas mileage is improving ~20% while towing on premium fuel. The caveat to that is the premium is also ethanol free so that may be part of the gain and not just the octane.
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07-02-2019, 10:07 AM
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#39
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Senior Member
Join Date: Dec 2018
Location: Quimper Peninsula, Washington
Trailer: TBD
Posts: 369
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Quote:
Originally Posted by MikeS
The caveat to that is the premium is also ethanol free so that may be part of the gain and not just the octane.
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I'm thinking the availability of ethanol-free premium is not universal.
__________________
Thanks,
~Farther
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07-02-2019, 11:16 AM
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#40
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Senior Member
Join Date: May 2015
Location: Lincoln, Nebraska
Trailer: April 2016 21' "Ramble On"
Posts: 280
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In my experience, Ethanol free premium availability varies widely from station to station in the "corn belt". Would love to see data as to whether the extra cost of ethanol free premium is worth the tradeoff in extra cost for extra MPG. I'm sure it depends on many factors but I'm curious.
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Do what you can, with what you have, where you are.
Theodore Roosevelt
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