McGirk94LT1

It's all hypothetical absolutely, from every angle.

The auto camaro from what I did a quick search on, gets 1 better mpg highway then the manual, despite being all but 200 higher at or 70(I believe someone said 1195). That's not tons, but it should be enough to make a difference in epa testing. Despite that, it's still rated 1mpg better. A lot of it is gearing, I'm always perplexed when a company releases cars with new transmissions, the top gears usually split the difference between performance and mpg. I mean, the 6 speed was introduced for mpg purposes, why stray from it especially now. I can't imagine the cruising power being sooooo much worse(or even notable) if the camaro automatic cruised at even 100 rpms below the manual but hey, what do I know.

The cruze eco drops to <3050lbs, with better aerodynamics and taller 3-6 gearing from the info I found. 138hp and 148lb ft. As I said, matching a v8 to those numbers is completely hypothetical, especially considering the lowest hp v8 vette I believe was the carb'd, California only, 305ci 76vette with 145hp lol. Its not gonna hit 42 highway, I know its not possible, but a direct injection, afm next gen v8 could be close... again hypothetically in the cruze. Wether its current displacement geared incredibly tall and totally focused on low end torque, or through say a 5.5 that makes impressive power for its size. I don't think they could even try to get either down to 200hp though.

The new, lighter camaro v6 is 345lbs while the ls3 comes to 403. Almost 60 exactly. Not surprisingly, I couldn't find the weight of the 1.4 turbo, though I'm sure its probably around 80-90lbs lighter all things considered(including turbo). Again, making space for a v8 is all hypothetical because they'd never do it from the factory.

My main point was small, forced induction cars are not the end all, be all as most claim them. Either the mpg or power/powerband is usually sacrificed in the real world. Despite being the same displacement and having direct injection, Audi's surcharged v6 doesn't make the power Mercedes did with the slk/c 32 amg's. And those were sohc 3 valves even whose design originated in the late 90's. Better mpg yes. Why not better power though I have no idea. Its in the 5 series now, power is clearly needed to move one of them along. As for the f150 ecoboost, my dad has talked to 3 guys that said they didn't get the rated mpg and after checking out a huge thread on mpg on an f150 forum, it sounded as though about 70% weren't, 20% were, and the other 10% were claiming blatant lies such as 30mpg hwy. Amazing torque curve, but real world mpg just isn't there. And I can only assume after the recent disaster about the Honda not getting its rated mpg, people are listening more closely to what others are saying about actual mpg.

/rant.

Ltrain925

I have to second this, you have to remember its not a flat 4 its still a V8, it will still sound like a V8, how i know this is because when i built my 85 trans am we somehow didn't hook up half the engine and only 4 cylinders were firing when we started it up, one set of headers were cold others were hot. Me and my dad were dumbfounded because we couldn't tell from the sound of it, it sounded like a raped ape with open headers. SO i have personal experience that it won't sound like a 4 cylinder but i bet you could tell a difference just not as drastic as you think.

Jinx

I believe there's a fundamental advantage to right-sizing the engine size for the most common load expected. An engine is more efficient operating at lower speed with more throttle -- hence skipshift.

What we may be seeing is the difference between the way the EPA test cycle accelerates from a stop, gently, and the floor-it-until-I'm-at-cruising-speed technique most drivers seem to employ, at least in my neck of the woods over the last 25 years.

Meaning, manufacturers are rightsizing the powerplant and setting up the gearing so that the engine operates at low rpm and high load through the EPA test acceleration profile, to maximize the published fuel economy figures on which sales depend... but the penalty for "decking" cars so optimized is higher than it was for those cheaper lazier lower-tech larger-displacement motors that used to be there.

This doesn't mean the smaller-displacement forced-induction approach is fundamentally less efficient, it may simply mean that the optimization point is a little low because the EPA test isn't how many of us really drive. Put another way, real-world drivers are demanding "too much" power and putting the engines in a less-efficient part of their operating range, i.e. higher rpm.

Could be as simple as optimized for low-end torque (efficiency) vs high-end horsepower (power). Horsepower is just a function of torque * rpm.

I don't think your idea of a larger engine running at lower rpm is too far off the mark, I just think a naturally-aspirated big V8 is overkill. The 2.0L EcoTec turbo, tuned and geared to stay under 4000rpm, might do better the way people actually drive than the 1.4L or 1.6L turbos. In fact, if you keep the revs down, I wonder if a four-valve design is even the right approach.

But is their actual fuel economy still better than it would be if the same drivers were driving V8s instead?

For that matter, do they really drive the EcoBoost the same way they'd drive a V8, or are they subconsciously giving EcoBoost more gas because it sounds different or throttle response off idle is slightly different or they just know there's a V6 in there and you have to give V6s more gas...

The driver is still the biggest factor. Unless you're driving with a really light foot, do you really have a leg to stand on when complaining about fuel efficiency?

And -- this is the big one -- since the fuel economy test is a government specification, if your actual mileage doesn't match the test results, shouldn't you be suing the government for their misleading test, not the manufacturer for adhering to the government mandate?

.Jinx

JoesC5

But my 4 cylinder supercharged 2.3L engine in my 3250 lb sedan(EPA 19/29) with a Cd of .27, but with a larger frontal area, then my Z06(EPA 15/24), gets better gas mileage then my Z06. My Z06 runs 1700 RPM at 80 MPH and my sedan runs 3,000 RPM at 80 MPH. In real word driving, I get 29 MPG in my sedan and 26 in my Z06 driving at 80 MPH, but with in town driving I'm getting around 5 MPG better gas mileage with the 4 banger(and that includes some acceleration where the supercharger is puffing pretty hard). With the supercharger being an "on demand" power adder, my sedan's motor seems to be matched pretty good to the car and had no problem on very steep hills, because the supercharger engages via it's electric clutch, giving my sedan the power when it needs it, but not when it doesn't need it. And my sedan is 1999 technology.

Disclaimer.....My Z06 does accelerate faster then my sedan but the gas gage really goes south when I do that.

tuxnharley

How in the world are those two statements consistent? Geez - just what we need, someone advocating more lawsuits for what is really just a lack of personal responsibility!

I know, I know - let's have the government mandate controlled network driving systems on highways. That way we'd all accelerate at the same rate, drive at the same speeds, and get the same mileage. Heck, they could even mandate that we all drive the same cars! That'd take the variables out of the mileage rating and real world attainment.
Yeah, that's the answer.......................:lol :

Jinx

JoesC5: I'm sure your Z06 is running on the same tires as your 1999 wunderkar, too.

tuxnharley: take a chill pill. Your eagerness to ridicule missed the point. Scapegoating manufacturers accomplishes nothing. Those two statements are consistent. If no one can achieve the test results, the test is bad and should be fixed. Otherwise, good luck with a suit against the government.

tuxnharley

Well, it was easy to miss your apparent point, since you didn't actually make it until you modified your position and defacto retracted your now apparently sarcastic suggestion of the first post with this statement in your riposte above.

Clear as mud, eh? So was your point.

And no, those two statements were not consistent despite your attempt to make them so with your "explanation"/modification. One suggested the driver is at fault, and the next suggested suing the Government for a bad test methodology. C'mon, surely you see the dichotomy there........?

Who said "no one" can achieve the same results as the test? Everything I hear - and read in these Forum threads - is that some do worse, some do better, and some hit the mark. Seems reasonable to me.

How do you propose to make one test that will duplicate multiple varying driving styles? Maybe it's time for people to take individual responsibility instead of expecting the Government to take care of everything for them............?

Jinx

Who pissed in your corn flakes? Seriously, don't stay in Angrytown, the food there sucks.

The suit against Honda was brought into the discussion. That wasn't just a case of a few leadfoots getting lousy mileage; many drivers, even some doing their best to be green, got unsatisfactory results, much worse than the typical variances for other cars. But Honda followed the rules. Should Honda be blamed?

Monroney mileage figures got a mathematical adjustment in 08 to make the EPA test results better represent real-world results. The test wasn't altered, they just started applying a fudge factor.

Put those two together -- does that sound like a good system?

Yes, the two statements you culled from my long post are consistent, because they aren't describing the one true answer to all fuel economy questions, they're commenting on a large issue. There's more than one possibility at play here.

Drivers need to take personal responsibility, and look to their own driving habits and technique first.

But there's still reason to question the validity of the federally-mandated system that provides consumers with fuel economy information.

Sorry I wasn't more clear, but I ask you to go back and read my original post with this in mind and see if it sparks further constructive discussion.

And maybe go a little easier on the hyperbole sauce.

.Jinx

tuxnharley

Maybe you missed the in my first reply to you....?

Hyperbole (per above)? "eagerness to ridicule" (from your 2nd to the last post to me)? Try reading the first and last lines in your own post above again... That's like the encyclopedia calling the dictionary verbose......... Why do you feel the need to escalate the discussion from a technical disagreement to a personal attack? I checked my corn flakes; they're fine............

It read as if you weren't just questioning the system but suggesting that folks sue the Government over it. I take it from your subsequent posts that you have backed away from that statement?

OK you win. This obviously isn't productive, so this is the last I'll post to you about this particular issue (unless you really p!$$ me off....)

Have the last word if you want.....

McGirk94LT1

Correct. Myself at least(and everyone else I assume) are not baffled by this. The surcharged 4 cylinder is in no larger cars, only slk and c class I believe. Its reasonable to say given that then, that it is matched to your car. Thus comparing a 7.0 505hp is a moot point. It is in no way, shape, or form set up to power your Benz. And even as I suggested if the theoretically would fit a naturally aspirated v8 in a cruze it would need to be detuned somehow to 200 or less hp and still wouldn't get the exact same mpg. Its really all nonsense since as Jinx pointed out, a 4 vs 8 comparison/swap is extreme overkill and not even realistic. Imagine the ls7 in your Benz however, tuned for greater low end via intake and cam, and geared even taller. As you admitted, they are remarkably close in the real world, considering one makes 2.5 times the power of the other. If the ls7 was able to lug along at even lower rpms just as comfortably, you don't think think it would be within 1 or 2 mpg highway AND city of your surcharged ?

My beef is with comparable engines(turbo4/v6, turbo6, pushrod v8) where the smaller engine is claimed all around superior. The ecoboost trucks seem to counter that argument pretty effectively "from what I've heard." They copied the diesels stump pulling torque characteristics by hitting almost full boost off idle. In the real world as most seem to say, that power does indeed come at cost of mpg which, as a whole, the entire auto field seems to be denying. Then again, as a whole, the auto field doesn't produce OHV engines anymore save for Chevy and the hemi/srt10. And we all know how the comparable hp OHV vs. DOHC results go in respect to mpg, so maybe their marketing isn't that off.

Jinx, I understood your point perfectly. You bring up a good point that maybe turbo 6 DRIVER A might get worse mpg then v8 DRIVER A(instead of engine to engine comparisons). However, as a whole over the years I've found just from word of mouth v8 trucks to be fairly accurate. Its only those that admit to cruising at 80+ that seem to be unhappy with their 4.11 geared v8 truck(duh is the only word that ever comes to mind). The majority of ecoboost v8 owners that said they don't get what its rated at still tend to give it a thumbs up for its power all over the rpm scale. To me, that says they feel its low end grunt and probably think it feels even stronger then most v8's(as it should) so wouldn't one think that they know they don't have to rev it to 4500 despite its v6 stigma? Strictly just my view. I'm sure others interpret that differently. I'm not a truck guy myself.

Harley, do you think the mpg rating system shouldn't be on cars in the first place? Heck its on motorcycles and how many really car when it comes to that? He brings up a good point that if Honda makes a product that say, makes 200hp on their, Ford's, and Audi's testing procedure, but 240 by EPA standards then why should Honda be punished? I myself have no answer, other then maybe before, and post testing Honda verifies the testings be true and fair, thus putting themselves in a binding position.

If you're not opposed to mpg testing in the first place(why would you be?) then why be opposed to them doing it right the first time, instead of applying what they FEEL is a realistic variance factor across the board which is sure to render some less accurate then others. Imagine if their testing was based on running a car to its peak hp every gear. That would be a God awful test procedure and would need amending wouldn't you agree? Jinx wasn't suggesting that. However if the epa testing is not reflective of real world, then what good is it? They still have to do it, so might as well do it right, right?

tuxnharley

In my opinion, the test is - and can only be - valid for the purposes of relative comparisons among vehicles, not absolute values. You simply can't design a test that will replicate real world conditions when there are so many variables - like driving styles , geographic location, climatic conditions, etc. - that the test cannot possibly emulate.

Like I believe it says right on the window sticker - "Your results may vary".

jackhall99

Nothing is guaranteed in life Glenn. Most of us understand that.

Jinx

Calling that eagerness to ridicule is not hyperbole. You jumping to the government-controlled vehicles scenario is hyperbole.

You escalated, I responded. You expect your smilies to undo the harshness of your statements but don't allow my lighthearted phrases to do the same. Don't play the "personal attack" victim card like a coup-fourre. Come on, man.

I did not advocate more lawsuits for what is really just a lack of personal responsibility. Your misinterpretation led you to that conclusion. Sorry about that.

You use forum trigger phrases. It seems needlessly aggressive to me. Take an extreme interpretation of a comment so it's easy to criticize, and then further criticize clarification as if it were weakness? I can't back away from a statement I didn't make in the first place.

We can discuss the state of fuel economy testing further if you like, if it's an honest exploration and not a wrestling round in search of a quick pin. What do you say?


You're right that a test can't replicate the full variety of real-world conditions. I don't think anyone expects it to. The fuel economy numbers are by their nature reductitve. However, there is an expectation that if your driving style was within a few percent of the EPA figures for your last car, the same should be true of your next car. If that expectation isn't met, the EPA figures aren't so useful. Maybe it's asking too much of the system, but maybe it's the test and not the idea that's flawed. The actual test hasn't changed in a very long time. It's been band-aided and still shows signs of strain. Technology is very different from when the test was devised; maybe the assumptions that made it a good indicator across the product spectrum in the 80s aren't so good anymore.

.Jinx

jackhall99

Not my discussion, but the petty crap is getting old. Flawed test or not, it is what it is.

I drive my Corvette conservatively, and get my foot in it also. I figure I'm the average Corvette driver.

On the highway, I exceed the tested highway results by several MPG, topping 30 easily.

Around town, I am in 100% stop and go, rarely more than an eighth of a mile at any steady speed, and I'm below the tested city mileage by several MPG.

It is what it is and who frankly cares? Can the pissing match stop kids?

petermj

what is the weight difference of four vs. eight cylinders? The car may be running on four cylinders but the weight is still there.

McGirk94LT1

I'm sure you, among the 99% of corvette owners say its a sports car, the mpg isnt why you buy it. Thats not a wrong motto at all. However, to say it is what is is and it doesnt matter is wildly incorrect. Maybe you don't care, but the tests being accurate or not essentially could cost companies milllions of dollars or more.

For a vette having its hwy mpg improved by 2 might not result in a single additional sale. After all, if you want a vette you want a vette. But think about this. The 2012 camery v6(263hp) scores an impressive 20/29 while the v6 fusion sport(268hp) scores 18/27. While that difference isnt huge, it might be enough to sway some buyers to the camery even if they like the fusion better overall. However, if for 2014 model year the rating system was revised to reflect more real world numbers, and the camery dropped to 18/27 and the fusion rose to 19/28 there might be a gradual shift in sales favoring the fusion. A revised rating system could completely change the rating on some cars, swinging buyers to their competition instead. Thats a critical part of this thread, as the v6 turbos might not be putting out such nice numbers vs their v8 rivals(thus completely destroying Ford's "power of an 8, with the economy of a 6). Then again, they might just as easily wind up better.

So while you think we should all just accept the rating system for what it is, I disagree. If it really hasn't been "updated" since the 80's(admittedly I havn't done much research on it), then maybe its past due. Catalytic converters came out in the 70's, but I'm sure no cars follow their exact designs today.

Also, as I pointed out, if the ratings in question were hp not mpg, I'm sure everyone on here would be up in arms if their cars weren't making quite the power they say they should. And shouts for restructuring those tests would flood the internet. So why shouldn't the mpg system be "accurate?"

McGirk94LT1

The newer, light weight lfx v6 in the camero is 345lbs vs 403lbs for the ls3, almos 60lbs exactly. The turbo 4 probably doenst weigh all that much less(including turbo and piping which is only fair) so 80lbs is probably fairly accurate. 80lbs is a failry moot point when your talking about steady highway speeds of 60-80 though.

JoesC5

The gas mileage as posted on the window stickers are for the consumer to be able compare that particular car vs other cars of the same clasification. It is not meant to represent the actual gas mileage, as they give a range (in the small print) that represents various drivers under various driving conditions.

As long as the tests are the same, when done on the various cars, then the tests meet their intended goal. That car "A" has 2 MPG better gas mileage ratings then car "B", but 1 MPG less then car "C". Of course, the numbers on the window sticker also gives the consumer an idea how the particular Corvette he is looking at compares to a new Silverado he is also thinking about purchasing.

jackhall99

Thanks Joe. I guess some still do not understand the number is a relative number, and has nothing to do with actual results.

tuxnharley

Wow - so explain to me how this was all just a "misinterpretation" on my part? It appears pretty clear that you can attempt to back away from a statement you did make - unless some how I'm just, as you put it, "misinterpreting" what you are literally and verbatim quoted as saying. Seems like your definition of "misinterpreting" really means "oh cr@p, caught in my own words, so I'll try to wiggle out of it by saying the other guy didn't understand what I meant".

Sounds like something out of Bill Clinton's book of tricks.............

Nice try, though..........

I guess maybe any hope of you and I having a productive discussion was just 'Jinxed" right from the start........

No smiles here.