Turbo 2.0L 4cylinders - Beat V6s? (Ecoboost, etc.)

[FetchFar]

Originally Posted By: supton
Are any of the recent motors very different in lbs of fuel burned per hp? Put your foot into anything, and it burns gas to get the job done.


They vary a bit... One of the big keys is compression ratio: The higher it is, the better the MPG & power. Thats how Mazda beats the VW Passat 1.8T in MPG & power both. ... Another important factor is number of transmission gear ratios, 6-speed OK, 8-speed is better, CVT is great. And of course the weight & aero drag, although 'most' of the cars I chose for the list are in the same category of weight range. Other engineering quality feats of technological prowess come in the area of clever engine computer control software algorithms used. Bottom line, the car maker that can deliver the most power for great MPG wins.

 

[OneEyeJack]

If you keep a car for a long time a 4-cylinder means one head, one exhaust header and should mean less complication with extended maintenance of say a 10 to 15 year time period. A 4-cylinder might mean easier routine maintenance, as well. If a car is a transportation device the new 4-cylinder engines do a good job and have enough power. If you looking for performance there are other choices.

 

[FetchFar]

Originally Posted By: OneEyeJack
If you keep a car for a long time a 4-cylinder means one head, one exhaust header and should mean less complication with extended maintenance of say a 10 to 15 year time period. A 4-cylinder might mean easier routine maintenance, as well. If a car is a transportation device the new 4-cylinder engines do a good job and have enough power. If you looking for performance there are other choices.


My criteria for the list was: Car must be fast and get great MPG, and 2.0L turbo4s and v6s seem to be about all there is if you want that in a car that weighs 3,xxx lbs. A non-turbo 4 is great if you don't care about the 'fast' part. Only problem with 4 cylinders is they shake too much compared to a 60 degree V6, adding stress to ancillary devices like water pumps, oil pumps, chains, etc., so I think a V6 would survive longer than a 4.

 

[jigen]

Fast and great MPG is a tough criteria to meet. What would be "fast" and what would be "great MPG" in your personal opinion?

 

[wemay]

Originally Posted By: 19jacobob93
I'd rather have a 6 over a turbo 4 any day. Mainly because I've had 4 (inc turbo) and 6 cylinder cars and I prefer the smoothness of the 6s. Also the 6 cylinder will always be more reliable (for most makes at least)


Our Hyundai 2.0T (265hp 270 lb ft) is much smoother than than our Infiniti 3.7L 6 cylinder (330hp 270 lb ft). Don't get me wrong, I love them both, just making an observation.

 

[FetchFar]

Originally Posted By: jigen
Fast and great MPG is a tough criteria to meet. What would be "fast" and what would be "great MPG" in your personal opinion?


Mostly anything that pushes the envelope of whats possible. Like the Accord v6, its fast by any standards, and gets great MPG. Always a compromise though. Tradeoffs. Some have a better combination of the two. .... One could define "fast" as any 0-60 under 6 seconds, its arbitrary, subjective of course, whatever you can afford/want.

 

[FetchFar]

Originally Posted By: wemay
Originally Posted By: 19jacobob93
I'd rather have a 6 over a turbo 4 any day. Mainly because I've had 4 (inc turbo) and 6 cylinder cars and I prefer the smoothness of the 6s. Also the 6 cylinder will always be more reliable (for most makes at least)


Our Hyundai 2.0T (265hp 270 lb ft) is much smoother than than our Infiniti 3.7L 6 cylinder (330hp 270 lb ft). Don't get me wrong, I love them both, just making an observation.


Hyundai must have done a great job of balance shafts and hydraulic engine mounts. A 4-cylinder has inherent internal imbalances which produce unavoidable shake. I did drive a '12 Infiniti G37 last year (rental car in Phoenix, yeah, nice) with that 330 hp V6 and I'm trying to remember if I noticed anything unusual about the vibration; can't recall.

 

[19jacobob93]

Originally Posted By: Miller88
Originally Posted By: 19jacobob93
I'd rather have a 6 over a turbo 4 any day. Mainly because I've had 4 (inc turbo) and 6 cylinder cars and I prefer the smoothness of the 6s. Also the 6 cylinder will always be more reliable (for most makes at least)
When turbos kick in it's a good feeling for sure but in a straight line the 6 I own now is quicker and has power from a breath on the pedal without the turbo lag
There are a lot of turbo 4s out now that use more fuel than their 6 cylinder brothers because of the way they get driven, i.e. Keeping the revs up to keep the turbo working


Drive one of the new ecoboost engines. I always thought it would be hard to get something with the torque curve of an old I6 - other than a split second of turbo lag, the 2.0 EB I4 just feels MUCH better than my AMC I6.

I'll still take an I6 over anything.


They introduced the 2.0 Eco boost on the latest falcon as a free option alongside the 4.0 I6. The ecoboost only has slightly less power and torque and does 0-62 in 6.something seconds.
Pretty good but they've also turbod the I6 which is hideously powerful now!

 

[FetchFar]

Originally Posted By: 19jacobob93
They introduced the 2.0 Eco boost on the latest falcon as a free option alongside the 4.0 I6. The ecoboost only has slightly less power and torque and does 0-62 in 6.something seconds.
Pretty good but they've also turbod the I6 which is hideously powerful now!

Looks like the current Falcon would perform about the same as the U.S.'s Ford Fusion, similar weight, with that same 2.0L ecoboost, 0-60 in about 6.6 seconds. Ford will probably put that engine in the Mustang making it to Australia in about a year and a half.

 

[sciphi]

The answer is: It depends on the engines/transmissions and vehicles in question.

I'm pretty well sold on turbo 4's. Driven carefully, they do a great job compromising between power and fuel economy. But, a not too careful driver will tank the fuel economy instantly.

 

[gofast182]

Originally Posted By: 440Magnum
A turbo 4 is definitely in the same power/torque zone as a V6, and will ALLOW (key word!) the driver to get better mileage if they choose to keep their foot out of it. Turbo lag is pretty well eliminated these days, too. The current crop even has fairly good vibration suppression compared to 10 years ago, but an inline 4 will *never* have good inherent balance and will produce more vibration without bigger fluid-filled or elastomeric engine mounts than a similar powered v6 (which in turn has less ideal balance than an I6) and balance shafts. They're fine for appliance cars, but I can't stand the feel/sound of most inline 4-bangers. I'm not a member of the Church of Subaru, but the boxer 4 is definitely the best way to go if you're limited to four cylinders.


So what's the point then? In order to get your turbo to provide great economy you have to drive it like it's a Corolla. The fact is the EPA test cycle doesn't do a great job of reflecting how most people drive, automakers design and tune to this test, and thus the consumer is put at a disadvantage when they drive the same car "normally" and struggle to get the rated MPG.
I have a bias toward Honda but it's hard to argue that they don't make some of the best *transverse* I4 and V6 engines available.

 

[supton]

Originally Posted By: gofast182

So what's the point then? In order to get your turbo anything to provide great economy you have to drive it like it's a Corolla.


FIFY.

Besides: what is "great" FE anyhow? Meeting EPA highway? Exceeding it? Getting to 80% of EPA city because your city commute is simply that bad?

Turbo I4's are a smaller lighter engine package than a bigger NA. They can have a flatter torque curve too. They can also respond nicely to tuning, assuming it wasn't already more or less pushed to the max already.

 

[440Magnum]

Originally Posted By: FetchFar
Originally Posted By: wemay


Our Hyundai 2.0T (265hp 270 lb ft) is much smoother than than our Infiniti 3.7L 6 cylinder (330hp 270 lb ft). Don't get me wrong, I love them both, just making an observation.


Hyundai must have done a great job of balance shafts and hydraulic engine mounts. A 4-cylinder has inherent internal imbalances which produce unavoidable shake.


Exactly, at least for INLINE fours. And even if there are balance shafts and oversize engine mounts, the stresses caused by the inherent imbalance are still there, inside the engine. The crank is pushing one way on the block, and the balance shafts are pushing the other way so it seems smooth on the outside, but the bearings "feel" the force same as if there were no balance shafts (worse, actually). And I never liked the fact that the balance shafts spin at 2X crankshaft speed- so when you hit that 6000 RPM redline, the balance shafts are zinging along at 12,000 RPM.

 

[FocusTi]

I don't know that they'll necessarily 'beat' V6s rather than just offer a slightly more economical alternative to them. I've been pleasantly surprised by the modern turbo-4s I've driven recently (Fiesta ST, Focus ST, Fusion Titanium, Escape Titanium). They're a far cry from the 1991 Talon TSi I had in regard to how much power they put out, and the lack of turbo lag.

I had a 2013 ST for a while and LOVED it. Probably the best of the 21 cars I've owned. Using the required restraint to get good mpg numbers was all but impossible, as the thrust was addictive. I averaged 26 mpg with it in mixed hwy & city driving. I think Ford did a great job tuning out the I4 vibrations, and it had nearly zero turbo lag. I traded it for a '12 3.0 V6 Fusion. Nice car. It always averaged 24.2 mpg, and I enjoyed that engine too. I felt like I was driving somewhat of a 'classic', as V6 midsized sedans are starting to show signs of extinction, unless you're shopping the luxury brands. I can see Honda, Toyota and Nissan following Hyundai's and Ford's lead in that respect.

I traded the Fusion for a '14 Focus Titanium 5-speed, which is averaging 29.0 mpg. At 160hp, I'm WAY down on power, but I like the car a lot. It'd be the perfect car if it came with the Fiesta's 1.6T.

 

[rjundi]

I drove the BMW 328 and found the motor 2.0L to be rubbish for a car its price. I prefer the BMW I6 in 323i form I was given as a company car.

 

[Quattro Pete]

Originally Posted By: rjundi
I drove the BMW 328 and found the motor 2.0L to be rubbish for a car its price. I prefer the BMW I6 in 323i form I was given as a company car.

Hmm... I drove a 328i GT (pretty sure it's the exact same engine setup as in a regular 328i) and thought it was awesome - very responsive and lots of power. The engine was very smooth and it would certainly spank my 530i I6.

 

[Kiwi_ME]

Originally Posted By: 440Magnum
Exactly, at least for INLINE fours. ... the stresses caused by the inherent imbalance are still there, inside the engine. The crank is pushing one way on the block, and the balance shafts are pushing the other way so it seems smooth on the outside...

But every piston engine has this characteristic, irrespective of what the sum of all cylinders might be.

Originally Posted By: 440Magnum
.. but the bearings "feel" the force same as if there were no balance shafts (worse, actually). And I never liked the fact that the balance shafts spin at 2X crankshaft speed- so when you hit that 6000 RPM redline, the balance shafts are zinging along at 12,000 RPM.
But the piston acceleration causing that imbalance is also at 12,000 time per minute. It's a doddle for a couple of small shafts to do that.

 

[440Magnum]

Originally Posted By: Kiwi_ME
Originally Posted By: 440Magnum
Exactly, at least for INLINE fours. ... the stresses caused by the inherent imbalance are still there, inside the engine. The crank is pushing one way on the block, and the balance shafts are pushing the other way so it seems smooth on the outside...

But every piston engine has this characteristic, irrespective of what the sum of all cylinders might be.



That's actually not correct. The 2nd-order (2x crankshaft speed) imbalance in the plane of the cylinders is unique to the inline 4. No such imbalance exists at all in an inline 6, which is a perfectly balanced arrangement (as is the V12, which operates as paired inline-sixes) so there are no unbalanced forces, other than combustion forces, acting on the main bearings at all. If you externally spin an inline 6 with no cylinder head to remove compression forces (say, motoring it on a dyno), the crank spins with no forces on the main saddles at all. Do the same with an inline 4, and the crank makes the block "bounce" at twice the crank rotation speed, which is why the balance shafts also spin at 2x crank speed.

There are residual higher than 2nd-order imbalances in v6 and twisted-crank (American type) V8 engines, but they are far less in magnitude than the inline 4 issue. 60-degree V6 engines have a different spectrum of imbalances than 90-degree v6s, and some designs retain a small amount of odd-firing, but at its worst a V6 still has closer to neutral balance than an inline 4.

A flat-crank V8 (eg. Ferrari 308) operates as two inline 4 engines joined at a 90-degree angle, so it has *two* sets of inline-4 class imbalances at right angles. Which is why its so unpopular and uncommon outside racing. It makes for a very lightweight crankshaft compared to a 90-degree or "twisted" crank v8, so it has advantages in racing where longevity and harshness don't matter as much. Its a filling-rattler without lots of damping.

 

[Kiwi_ME]

Yes, I'm totally aware of the engineering statics 101 but every piston is pulling and pushing it's own con rod bearings and crank journals. The fact that the sum of forces or moments for the entire crank works out to whatever total out-of-balance does not change the stress presented by each cylinder on it's local components.
Crank rigidity comes from block rigidity.

Read your post again about the bearing stress...

 

[19jacobob93]

Originally Posted By: FetchFar
Originally Posted By: 19jacobob93
They introduced the 2.0 Eco boost on the latest falcon as a free option alongside the 4.0 I6. The ecoboost only has slightly less power and torque and does 0-62 in 6.something seconds.
Pretty good but they've also turbod the I6 which is hideously powerful now!

Looks like the current Falcon would perform about the same as the U.S.'s Ford Fusion, similar weight, with that same 2.0L ecoboost, 0-60 in about 6.6 seconds. Ford will probably put that engine in the Mustang making it to Australia in about a year and a half.

Yeah it's around 6.8 secs I believe. The falcon is bigger and heavier than the fusion and is RWD, engineered for it's big I6s and V8s so to get that kind of performance out of a little 4 banger is impressive!
Yeah the Eco boost is getting put into the mustang in the base model along side the V6. This will probably rival the Toyota gt86 here so they better price it just as low ($29k) but the Eco boost will be much faster. The higher end getting the v8. I reckon the Stang will do well over here!