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2013 Ford Escape

663 messages,  Last post on Jun 18, 2013 at 2:32 PM

You are in the Ford Escape Forum.

What is this discussion about? Ford Escape, Car Buying, Car Comparisons, SUV

Messages Page 16 of 67

#146 of 663 Re: Ford Escape 2013 Special Features [wwest] by bigmclargehuge

Sep 10, 2012 (1:02 pm)

Replying to: wwest (Sep 06, 2012 3:45 pm)
No, a DFI engine with a compression ratio lower than 10:1 is NOT efficient. SkyActive DFI engines are running a CR as high as 14:1. Yours would probably get much closer to 40 MPG were it not for the EcoBoost engines being so severely "detuned" in simple cruise mode, off-boost.
 
To summarize, NO.
 
Skyacyiv under 'cruising' will have a Dynamic Compression Ratio of only 7.9-8.9: :1 depending on throttle position.
 
Whereas Ecoboost will have a cruising ECR of 9.5-11:1 CR. On average, higher than Skyactiv.
 
ALL the literature out there supports this. I can link I you like, but maybe another thread would be better so the good people of the Ford Escape forum don't have to hear your ridiculous theories

#147 of 663 I must be LUCKY! by flbent

Sep 10, 2012 (1:37 pm)

OR, only the people with problems post. I Purchased A white tricoat SEL 2.0 With touch, park assist, Navigation, sunroof, blis, (loaded) In July. I now have over 4,800 miles on it Average gas (my calculations) mpg is 28. I had 1 problem with the car stalling on a hard acceleration(not good) 1 trip to dealership who talked with ford while they were troubleshooting, never saw the problem again and that was in the first week of ownership. My Ford Touch works fine for me. It took a while of sitting in the car with the instruction manual and several errors on MY part to get it. Nobody, but maybe Bill Gates, is going to hit the ground running with a new operating system like this. If you own one or are test driving one, the best place to start is ask: "what can I say?" read the screen, find what you deem useful and go from there. If your trying to learn and drive at the same time, GOOD LUCK. My favorite so far is to tell her "I'm Hungry" she ask local or in town and away we go to dine, actually found some great restaurants that i did not know about. But probably the most important thing MyFord Touch has done for me was getting myself to an ER after an injury. I didn't know where the closest hospital was, (wasn't life threatening, just painful) but i declared an emergency, then hospital, and the car guided me to help. It wasn't a lifesaving event by any means, but I think I appreciate this new technology a little more.
To sum "I like my new Escape"

#149 of 663 Re: 2013 Escape SEL 2.0 AWD Gas Mileage [ars2010] by al63017

Sep 10, 2012 (3:58 pm)

Replying to: ars2010 (Sep 10, 2012 8:33 am)
I have had mine since 24th of August just a few days past 2 weeks and display shows consistently now just over 27 mpg. Titanium 2.0 fwd.
Lot of local 15-20 mile trips with not much stop and go and 90 % Interstate and the rest suburban driving 40-45 mph. Using a calculator the mpg is a little over 2 mpg less. I have seen the drving style awards on MFT and not sure how they are calculated but have them on my display. I have seen almost 29 mpg on longer Interstate trips. I only have 700 miles on mine so seems like the EPA sticker is pretty accurate. They may be able to put your car on the diagnostic system and tweak a few things that relate to mpg. AWD will be slightly less mpg than fwd. I really like the vehicle more than anything I have owned and I hope your problems are resolved soon and to your satisfaction.

#150 of 663 Native vs effective Compression ratio. by wwest

Sep 10, 2012 (8:04 pm)

I have always espoused that effective compression ratio is equal to native/base compression ratio at WOT. Otherwise the effective CR is a function of throttle plate position.
 
But.
 
The issue of atmospheric pressure, as even in the vacuum of space, was brung up.
 
So what is the effective compression ratio vs native compression at at sea level/WOT vs 1000ft altitude/WOT..??
 
It is my opinion that the effective compression ratio does not change as a function of atmospheric pressure. There may be less "air" to compress, but what air there is will be compressed at the sae ratio as at sea level.
 
Thoughts?

#151 of 663 Leaking Still by novascotiaguy

Sep 11, 2012 (3:49 am)

My brand new 2013 Escape is now in the shop for the second time for a leak somewhere in the roof. It always shows itself on the door pillar head liner just at the top of the driver's side windscreen. Last attempt to fix meant removing and resetting the windshield. It still leaked.
I have heard of other people with this issue and even my dealer has one on the forecourt with the self same problem. This has to be an issue with these and I suspect there are many more.
My dealer is trying to help, but Ford are not coming clean with this.

#152 of 663 Re: Native vs effective Compression ratio. [wwest] by bigmclargehuge

Sep 11, 2012 (6:19 am)

Replying to: wwest (Sep 10, 2012 8:04 pm)
Wwest, you are being ridiculous.
 
I have always espoused that effective compression ratio is equal to native/base compression ratio at WOT. Otherwise the effective CR is a function of throttle plate position.
 
You've been spouting off in hundreds of posts on dozens of threads on multiple forums about 'cruising' and now you're backtracking to say WOT? The bottom line is, you've been wrong to criticize boosted engines then.
 
It is all over the internet if you'd bothered to comprehend it. At WOT, a N/A engine might approach its Static CR. But a boosted engine will be nearly doubling it. Under 'cruise' conditions, even the most advanced N/A engine will not even approach a dynamic compression ratio of 10:1. There are some 'ram-air' LS-engines that can go over their 10:1 N/A Static CR, because of air movement.
 
So thanks for wasting hundreds of peoples' time on dozens of forums for mixing WOT CR with near-idle CR.
 
Look up 'compression ratio calculator'.
http://www.rbracing-rsr.com/compression.htm
This is not the only one out there, and they use the same formulas. Applicable to ALL OTTO-CYCLES. This one includes altitude, per your request.
 
At 1000 ft, and WOT (assuming full cylinder of air, 0 psi = 1 atm) the Effective CR will be 11.8:1 on a 12:1 SCR engine.
 
HOWEVER, the Ecoboost delivers 15 PSI to the manifold at full boost.
Or 1000 ASL:
You are running 15 PSI of boost at an altitude of 1000 feet. Your motor's static compression is 10.5 :1. At this boost level and altitude your effective compression ratio is 21.01 :1, and without altitude correction your compression ratio would be 21.21 :1
 
Again, why the heck have you been using CR's as a measure of 'cruise' efficiency? That's more a factor of transmission, gearing and aerodynamics.
 
At 6,000ft (Denver) when the Skyactiv would be besting 10.8:1 CR at WOT adjusted for altitude, it would still get ~40 highway mpg. The power is what gets sapped. Less air available means less fuel burn. So you go slower under accel, but highway doesn't suffer all that much. You can have 40mpg at 160hp available or 40mpg with 140hp available. The effective compression ratio does NOT greatly affect fuel economy on a high plateau (flat ground).
 
You are married to compression ratios, which barely make up <1% of any efficiency gains between engines. Going from a 4-speed to a 6-speed to an 8-speed can see 20% fuel efficiency gains at each interval. So Ford should NOT 'abandon the Ecoboost' for some silly Skyactiv technology, because they wouldn't see economy gains like you've been alluding to. They should switch to an 8-speed transmission in their trucks and reap the benefits (like the newfangled Ram). Again, the 9.5:1 SCR Fiat Multiair (non-DI) in a Dodge Dart gets 42 highway mpg. Its turbos will operate with the same way, with an effective CR range of about 8.5:1 (slight vacuum at cruise) to ~20:1 (WOT). How many posts have you made where you use the WOT CR for Skyactiv, while you saddle the Ecoboost with a 'cruise' CR? That's not really fair argument when the EB peaks at ~20:1 effective CR.

#153 of 663 Simple.. by wwest

Sep 11, 2012 (10:26 am)

Assuming a throttle setting/opening resulting in equal HP cruise output a SkyActiv CR of 14:1 will result in a higher effective CR vs an Ecoboost starting at 10:1. Quite obviously the Ecoboost would need to operate at a higher RPM, more frictional losses vs the SkyActiv.
 
You can only win this arguement by raising the Ecoboost's native CR to 14:1 in order to "equal" the FE of the SkyActiv in simple cruise mode. If you then still wished to add "boost" you would either have to seriously ENRICH (that's what's DONE) the mixture to prevent detonation or maybe even somehow SUPER-COOL the charge airflow.

#154 of 663 Re: Simple.. [wwest] by bigmclargehuge

Sep 11, 2012 (1:29 pm)

Replying to: wwest (Sep 11, 2012 10:26 am)
YOU CANT WIN THIS ARGUMENT PERIOD, BECAUSE YOU ARE JUST SPOUTING LIES.
 
Everything you just said is based on your own goofy assumptions, and are blatantly false.
 
First off, 14:1 is a myth in the United States. Stick with 87 Octane ratings please. Plus, with premium fuel, the EB would allow more boost post-vent valve at all RPMs, as premium fuel resists detonation.
 
Second, NO NATURALLY ASPIRATED ENGINE approaches 10:1 effective CR during cruising. 9:1 absolute maximum.
 
No, turbo'd engines do not need a higher 'native' CR, they simple run mild boost off the turbos which results in a partial-throttle pressure near 1ATM. When you say 'obviously' you follow it up with a lie. So to correct you : obviously, from the Effective Compression Calculators that take boost into account, all you would need for the EB to run a higher cruise ECR than Skyactive would be to average 1ATM. Which they do. On the highway, the EB averages 1ATM. Sometimes a little higher, sometimes a little lower depending on wind/terrain.
 
NA engines can't come close to 1ATM under anything but WOT and higher rpms.
 
That is a fact. You lose, the real world wins.
 
Third, ARE YOU KIDDING about higher rpms on a boosted engine? HAHAHA!
You're ridiculous. Boost is NOT tied to rpms on turbocharged vehicles, and the benefit to boosted engines is more torque at lower rpms due to consistent air supply (turbo's producing 1-5psi under normal driving means the EB is consistently 2-10inHg higher on the vacuum / volumetric efficiency scale).
 
Clearly you are ignorant. Have you ever even looked at a dynamometer printout of a turbocharged vehicle? Peak torque arrives at 1500 rpms for the Ecoboost and 4000 rpms for the Skyactiv!!!! You have it absolutely backwards, Willard. In order for a naturally aspirated engine to even exceed 9:1 effective compression, it needs to be at a higher throttle opening, and a higher rpm that a turbocharged one. For any required torque, the EB will be at a LOWER rpm than Skyactiv

 
At absolute best, it's a wash between them in terms of efficiency, AS IS DEMONSTRATED IN THE REAL WORLD. You lose on account of NO DATA TO SUPPORT YOUR WILD CLAIMS.
 
I'm sorry you're too far gone into your own little world to ever get a handle on engine dynamics. You're hilariously off-base.

#155 of 663 Re: Simple.. [wwest] by bigmclargehuge

Sep 11, 2012 (1:26 pm)

Replying to: wwest (Sep 11, 2012 10:26 am)
There is more to look at than just peak torque figures, however. For normally-aspirated engines, peak torque is achieved at the engine rpm with the highest volumetric efficiency, which is typically in the 2,200 to 2,600 r.p.m. range. Volumetric efficiency is the percentage of the engine cylinder that is filled with air. Torque will increase as engine rpm goes up and then gradually decrease at higher rpm after peak torque is reached. When graphed, this produces a smooth curve shaped like a mushroom top.
 
Turbocharging changes all of that by changing an engine’s volumetric efficiency. Turbochargers can actually pressurize the air in the cylinder above atmospheric pressure, so volumetric efficiency rises even above 100 per cent. This produces more torque and over a longer rpm range. In the EcoBoost engine, the torque curve could more accurately be described as a torque “square.” It climbs rapidly to peak torque at 1,500 rpm and stays there continuously until engine redline. That means performance is strong at any rpm, and especially at common engine speeds. You don’t have to downshift or race the engine to get a lot of torque.
 
From Autos.ca
 
It is common knowledge that the entire torque range of turbocharging is lower, less friction involved. Because full boost (or any amount in the engine's range ) is available at 1500 rpms.
 
That means, contrary to your highly flawed understanding, the EB can be anywhere from 10.5 to 20.5:1 ECR at 1500 rpms. Whereas the Skyactiv will remain below the EB during cruising (more like 8:1) not even approach 12:1 until WOT and at 4000 rpms (I looked it up) and WOT.
 
This is a fact. You lose, reality wins.

You were as correct about this as you were the rest of your 'guesses'. I.e. completely off.

Messages Page 16 of 67

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