The age of engine downsizing is over, says Volkswagen

Rather Be Biking

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I am one of those people who got a 2017 Jetta S 1.4 TSI with my $500 dealer card that was going to expire in November. Just filled it up for the second time today, 577 miles on 13.3 gallons, which I calculate to be 43.4 miles per gallon in mixed driving. I tend to drive it like a diesel and use boost a lot. (Not sure if this is good for longevity, but it just feels good to me.) I'm certainly impressed - I can never get much more than 40 mpg with the 2014 Passat TDI DSG.
Same story here. My 2017 Jetta S with a 1.4 has actually been more fun to drive than my 2009 JSW TDI, and it's getting better mileage than my somewhat battered TDI. Plenty of power starting at a lower RPM than the TDI and I hardly ever get past 2500 RPM (except from time to time for maintenance purposes).
 

GetMore

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His opinion echoes a Reuters report last autumn which stated that new emissions tests had exposed flaws in downsized engines. In real life, the report stated, these turbocharged units have a tendency to overheat when their tiny turbos are called on to deliver real-world performance.

To combat this, the engine's software strategy will over-fuel the engine, which results in increased emissions of CO2, oxides of nitrogen as well as unburnt hydrocarbons, particulates and carbon monoxide.
 

oilhammer

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There are just too many to list....
Probably why so many of these smaller GDI engines have such sooty tailpipes. The tailpipe of my 21 year old F150 with over 100k miles is still clean, and that is with an engine that was designed sometime back in the 1960s and was hardly a cutting edge one at that. While my dad's 2015 F150, with its impressively powerful little 2.7L Nano V6 already is getting a black tailpipe and it has not even gotten to its second service interval.

Unloaded, though, that new truck does get better fuel economy. Not sure how it does loaded though, and chances are it never will be loaded very much anyway.
 

Ol'Rattler

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Computerized FI is much more efficient than a carb 9 times out of 10. What amazes me is how little the fuel economy has improved over the 75 Nova, 82 Olds, 84 Camry, and 87 Dakota with the new fuel systems, better transmissions, etc.
Huh? we haven't had carbs since the late 70's and some of last ones had some really messed up electronics and emission equipment tacked on to them.

I think that the FE on EFI cars was gobbled up by stricter and stricter emission standards. If we still had the same emission standards we had in the1960's and earlier's, EFI would have run circles around any carb in performance and FE.
 

oilhammer

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There are just too many to list....
Huh? we haven't had carbs since the late 70's and some of last ones had some really messed up electronics and emission equipment tacked on to them.
I think that the FE on EFI cars was gobbled up by stricter and stricter emission standards. If we still had the same emission standards we had in the1960's and earlier's, EFI would have run circles around any carb in performance and FE.
I think you are a little off there. Carburetors were largely non-electronic until 1981, and there were still some in use into the early '90s. The very last one on road going light duty vehicles was in 1994.

And many of the highest MPG gasoline cars were in the '80s, and did indeed have carburetors. The CVCC Hondas come to mind, but there were also the VV Tercels, and some pretty darn frugal carbed Mitsubishi and Mazdas too. They were not particularly powerful, but when EFI was largely limited to TBI or gang-fired port systems, or CIS, those carb engines did provide some pretty impressive MPGs. The highest MPG Honda Civic ever, even higher than the hybrids, had a CVCC carb. They could match a manual gearbox ALH TDI on the highway for fuel consumption. The EFI Civics sold right alongside them could not. :cool:

It has not been until fairly recently with not only SFI but far better injector designs, higher pressure returnless systems, much better air-fuel ratio management brought on by better ways to measure incoming air and wide band lambda sensors, more advanced variable cam phasing, direct injection, light pressure turbocharging, and just a general improvement in small increments here and there that has given some of the modern gasoline engines the ability to overcome some of the morbid obesity modern cars have been cursed with. Now once again, MPG numbers are going back up. Still, if you had a Civic-sized time machine and could bring me a factory fresh 1988 CRX HX I could embarrass a 2017 Civic at the fuel pump. Yes, it would be slower, and yes it is much lighter, and no it does not have all the equipment the newer one has. But its tiny carburetor could use very little gasoline to get you where you needed to go. And they were actually pretty fun to drive, too!
 
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kjclow

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Probably why so many of these smaller GDI engines have such sooty tailpipes. The tailpipe of my 21 year old F150 with over 100k miles is still clean, and that is with an engine that was designed sometime back in the 1960s and was hardly a cutting edge one at that. While my dad's 2015 F150, with its impressively powerful little 2.7L Nano V6 already is getting a black tailpipe and it has not even gotten to its second service interval.

Unloaded, though, that new truck does get better fuel economy. Not sure how it does loaded though, and chances are it never will be loaded very much anyway.
I saw a couple year old Hyundai sedan yesterday were both tailpipes looked worse than the back of my beetle when she had a fuel leak. Even dirty sticky diesel fuel wasn't as bad as all the soot on the back of the hyundai.
 

gmcjetpilot

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I will not even consider electric cars until they can meet this hurdle -
300 Mile range, no more than 30 minute zero to full charge (30 minute DIY full replace of battery pack would be acceptable - as long as it is generally available on the road). A total dismantlement of the TSA so flying is again more convient would be acceptable as well.

I'm not even all that fond of hybrid vehicles. But with the ICE giving the said 300+ mile range and refill requirements, at least they are more acceptable than pure electric.

You will never own an electric car in your life time...
 

gmcjetpilot

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What is old is new again... There have been tiny 3 cylinder even two cylinder cars for 50 years. There has been monster engines as well.

I thought I never own a turbo car, because I preferred Cubic Inches for power. However turbo increases efficiency especially for a diesel.

There is NO FREE LUNCH.... to get real tiny tiny cars is not popular with Americans who love Trucks, SUV's, Mini Vans and big touring cars. You need power to move that mass and all the stuff it hauls. Cubic Inches does that... You can turbo your 1 Liter all day long... it will puke compared to a 5 Liter normally aspirated.
 

gmcjetpilot

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What is old is new again... There have been tiny 3 cylinder even two cylinder cars for 50 years. There has been monster engines as well in the past, and they came back with a vengeance. Many of those monster V8's of course use cylinder shut down schemes to get close to high teens or low 20 MPG.

I thought I'd never own a turbo car, because complexity, reliability. I preferred Cubic Inches for power. However turbo increases efficiency especially for a diesel.

There is NO FREE LUNCH.... tiny cars need way less power to go, but they are not popular with Americans who love Trucks, SUV's, Mini Vans and big touring cars. You need power to move the mass and all the stuff those land yachts hauls. Cubic Inches does that... You can turbo your 1 Liter all day long... it will puke compared to a 5 Liter normally aspirated.

One day gas will go back to $5 or $10 a gallon and people will be running from those big gas guzzlers again. It goes in cycles.
 

tikal

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Good discussion going one here.

I read from time to time in this thread and others that perhaps the latest and greatest gasoline powered passenger vehicles are starting to 'catch up' fuel efficiency wise to the latest similarly sized/driven light duty diesel passenger vehicles. This might be true on an anecdotical basis but once you look up at aggregated data from Fuelly.com and the like you realize that the laws of Physic still favor light duty diesel passenger vehicles by around 20-30% in terms fuel efficiency.

Not only this, but from an environmental point of view, when you take into account the complete life cycle of the vehicle, only electrical vehicles using electricity from renewable sources and/or natural gas surpass light duty diesel passenger cars.
 

GoFaster

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The fuel consumption (by volume of fuel) advantage is still in favor of diesel but not by the margin that it once was.

If CO2 is your thing, that advantage slims down by about 10%.

If cost of operation is your thing, the extra complexity of the emission control systems and the HPFP and all the things that go along with those is going to go against whatever fuel savings may exist. In many cases the cost of operation may be higher if these systems aren't durable in the long term.

"Clean diesel" is when I switched back to gasoline engines ...
 

turbobrick240

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We can thank a rather ingenious Ontarian (2micron) for developing a solution to the hpfp issue. I'm driving my cousin's mx5 while runonbeer does some clutch work on my golf, and though the mx5 is a fantastic car, I do miss the torque of my little diesel.
 

whitedog

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One of my customers has a Transit with the Ecoboost engine and it gets worse mileage than their 2003(ish) Chevy 6.0 gassers. This is an electric contractor so there is a lot of in town, stop and go, short tripping. They also have two Duramax vans, but I don't know what their mileage is.

Another thing I thought of as I read this is that if the EPA allows excess emissions in certain conditions such as in WOT emergency type driving, with the smaller engines, aren't they running close to that situation more often?
 

whitedog

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Yes, the smaller engines are at higher specific load more of the time and that means more operation in enrichment.
So it makes me wonder if these smaller engines can pass the emissions test, but actually put out higher pollutants in Real World Driving than a larger engine working less hard and not going into the enrichment operation. Magic 8 Ball says, "Signs point to Yes."
 

bhtooefr

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And that's why downsizing is being reversed, now, in Europe, where this has been taken to extremes.
 

tikal

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Not so "clean gasoline vehicles" either

Here is an overall comparative graph with the so called "Clean Gasoline vehicles" and "Clean Gasoline-Hybrid Vheicles" vs the BMW X5 35d and other types of passenger vehicles:

You're welcome, tikal.
Thanks to a comment by bhtooefr, I searched for, and was able to find, a document that provided damage cost factors for both urban and rural emission scenarios, albeit it is calculated for Ireland ("Air Pollutant Marginal Damage Values Guidebook for Ireland 2015"). I'm still not able to run the APEEP model, which would still probably provide the best estimate of each vehicle technology/fuel pathway.
GREET provides total and urban emissions for both WTW and vehicle manufacturing. Thus, urban and rural damages can be calculated individually (rural emissions calculated by subtracting the urban emissions from the total emissions), and a "composite" damage derived from combining the urban and rural damages.
Using that methodology, here is a graphic of the results I get:

This shows EV in a better light, especially if it's a very clean grid like California (virtually no coal generation), since a higher percentage of emissions are generated in rural locations.
Edit: The "Diesel @X5" uses the average overall "real world" exhaust emission profile of the BMW X5 35d measured by WVU in the ICCT report.
 

GoFaster

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Are those graphs extrapolated from emissions established during something akin to EPA test procedures, or are they established from "real driving emissions"?
 

GoFaster

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So it makes me wonder if these smaller engines can pass the emissions test, but actually put out higher pollutants in Real World Driving than a larger engine working less hard and not going into the enrichment operation. Magic 8 Ball says, "Signs point to Yes."
An empty and gently-driven Ford F150 3.5 Ecoboost will probably use less fuel than an empty and gently-driven Ford F150 5.0 V8.

Hitch up a big trailer, and everything changes.

There are some engineering changes that can be done to control piston and exhaust valve and catalyst temperature and we are starting to see them in newer engine designs. The trickery is being able to raise the compression ratio without encountering knock while still being able to use a premixed charge (to minimize soot formation).

Example 1 http://newatlas.com/toyota-tnga-engines/46830/ 13:1 compression ...

Example 2 http://motorchase.com/en/2016/09/fiat-presents-the-new-firefly-gse-engines-in-brazil/ This engine has many interesting design features. 13.2:1 compression ... and without direct-injection and without 4 valves per cylinder, just a well-optimized twisted-hemi 2 valve design.

Example 3 http://www.allpar.com/mopar/V6/PUG-2015.php 11.3:1 compression ... this wasn't a ground-up redesign like the above two were.
 

atc98002

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Are those graphs extrapolated from emissions established during something akin to EPA test procedures, or are they established from "real driving emissions"?
Can't say for every column, but wxman noted at the very bottom that the X5 diesel was real world testing from the same university that started the mess for VW.
 

wxman

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Are those graphs extrapolated from emissions established during something akin to EPA test procedures, or are they established from "real driving emissions"?
The "vehicle operations" damages are based on emission factors established by EPA (see http://greet.es.anl.gov/files/vehicles-13 (Tables A2 & A3)).

The past few versions of GREET have started to deviate from the EPA emission factors somewhat, as can be seen in this screen capture of the GREET1_2016 output file:





Please note that the assumed NOx emission rate is still almost twice the T2B5 FTP "regulatory limit".
 

oilhammer

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There are just too many to list....
An empty and gently-driven Ford F150 3.5 Ecoboost will probably use less fuel than an empty and gently-driven Ford F150 5.0 V8.
Hitch up a big trailer, and everything changes.

Yep, but Ford realizes better who is actually buying and driving their trucks, and how they are using them....which is the vast majority of the time mostly empty. So who cares if the fuel economy tanks that 2% of the time the truck actually gets used as a truck?

I live in the middle of truck country, F150s are like mosquitoes here. Rarely do you see one loaded down with any sort of load nor see one towing a heavy trailer. Heck, we service fleets of F150s that never, ever see any kind of load coming even close to what even a half-ton truck could handle. For those people, a V8 is pretty useless. Even the Ecoboost options are overkill, most get by just fine with the standard 3.7L (and now 3.5L, and soon to be 3.3L) naturally aspirated V6.
 

NSTDI

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Oilhammer, are the smaller engines better on fuel than the turbo V8 or the V8's in real world driving with similar loads- mostly none?

Don
 

NSTDI

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An empty and gently-driven Ford F150 3.5 Ecoboost will probably use less fuel than an empty and gently-driven Ford F150 5.0 V8.

Hitch up a big trailer, and everything changes.

There are some engineering changes that can be done to control piston and exhaust valve and catalyst temperature and we are starting to see them in newer engine designs. The trickery is being able to raise the compression ratio without encountering knock while still being able to use a premixed charge (to minimize soot formation).

Example 1 http://newatlas.com/toyota-tnga-engines/46830/ 13:1 compression ...

Example 2 http://motorchase.com/en/2016/09/fiat-presents-the-new-firefly-gse-engines-in-brazil/ This engine has many interesting design features. 13.2:1 compression ... and without direct-injection and without 4 valves per cylinder, just a well-optimized twisted-hemi 2 valve design.

Example 3 http://www.allpar.com/mopar/V6/PUG-2015.php 11.3:1 compression ... this wasn't a ground-up redesign like the above two were.
I keep reading about direct injection causing valve carbon buildup on the back side of the valves and then a need for an expensive cleaning of the valves. How common is that?

Don
 

oilhammer

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There are just too many to list....
The F150's last generation had 3.7L V6 non-turbo, 3.5L V6 twin turbo, and a 5.0L V8. The Raptor also got a hyped up version of the 6.2L V8, but we'll leave that truck out of the discussion as it has over $3000 worth of shock absorbers, so I really do not think fuel economy was high on the list of attributes for those buyers.

Since there is such a giant span of curb weights with F150s, it is tough to lay a good rule of thumb to ALL of them with ALL the engines. A regular cab long bed 2WD truck is going to weigh less than a crew cab 4WD truck, even if that crew cab has that stunted useless 5ft bed on it. They also have different tire and wheel options, rear axle ratio options, etc. They call get the same 6sp slushbox.

The current generation went on a major weight savings plan with the aluminum body, so all versions are lighter. They also replaced the 3.7L with a non-turbo 3.5L, as well as added the 2.7L "Nano" V6. The 3.5L turbo and 5.0L V8 are carryover, with a couple of minor tweaks.

Driven with little to no load, the V6s (all of them) are going to use less fuel than the V8. The difference comes when they are loaded, then obviously the turbo engines will suffer more, because they have more available power to be made. I think the 3.5L turbo can do everything the 5.0L V8 can, but how much fuel it uses is largely dependent on how much load you are asking of it. Personally if you are driving around with a heavy load most of the time, a 1/2 ton truck is probably not the best choice anyway.

The Nano V6 seems pretty frugal, that is what my Dad bought. It is peppy to drive unloaded, and has good punch to get up to speed when you need it. It is surprisingly quick for its size. It can get into the mid 20s MPGs with light load and moderate speeds. His is a supercab, short bed, 4WD. Their previous F150, a 1994 model with the same cab configuration only 2WD and it had the optional 4sp slushbox would get about 19 asking it to do the same task. And it wasn't nearly as peppy (not even close). However, I doubt this new truck will give them the 300k miles of very low cost of service that the '94 did. Seriously, the 4.9L I6 in that truck never needed anything but oil changes and ignition parts changes, a thermostat, and I think a TPS once. That is about it. Didn't leak oil, didn't burn oil, didn't do anything bad. Big low tech lump of iron.
 

NSTDI

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"The Nano V6 seems pretty frugal, that is what my Dad bought. It is peppy to drive unloaded, and has good punch to get up to speed when you need it. It is surprisingly quick for its size. It can get into the mid 20s MPGs with light load and moderate speeds. His is a supercab, short bed, 4WD."

That's better fuel economy than my 3.4L V6 2002 4WD extended cab manual transmission Tacoma.

Don
 

turbobrick240

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Yeah, the ford 300 I6 is pretty legendary for its reliability. Right up there with the dodge slant 6. Just what you want in a pickup, IMO.
 

GoFaster

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The 2.7 Ecoboost is a next-generation design and is a good choice for the F150. The manufacturers are not standing still, and they know what the issues are with the original 3.5 Ecoboost (and that engine had modifications also).

Intake valve clogging ... Varies all over the map. Some engines have had big problems, others have not. In the cases of big problems, some drivers have it happen and others don't, so it probably depends on driving patterns as well.

I've opted to stay away from this until it's figured out. The non-turbo non-direct-injection Pentastar in my van does fine for what it is. I have a friend who has a Pentastar/8-speed combination in a Ram 1500 pickup, and he reports 11-ish L/100 km in normal driving (21 mpg US), which is OK for a vehicle like that.

The Toyota 3.4 V6 was never known for being thrifty.
 
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