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Mainstream Large Sedans Comparison

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Comments

  • martin22martin22 Posts: 53
    Gentlemen: Let me reiterate a post I made some months ago.

    Consider the formula from Newton's second law of motion..

    Force (in this argument, torque) = mass x acceleration

    Put another way, Acceleration = Force divided by mass.

    It's as simple as that: Acceleration is directly proportional to force (i e torque at the driving wheel) and inversely proportional to mass.

    That's the Law!
  • plektoplekto Posts: 3,738
    The reason HP is nearly meaningless these days is because we have artificial limits on how fast we can go in this country.

    Ie - There's no point to the 4th, 5th, or 6th gears in a 911. Because you get a ticket at anything over 70mph. So having 300hp on tap is worthless, really, except maybe if you manually shift it and only drive in 2nd gear or something.

    AND the race for ever-more HP leads to them constantly reworking the engines for it instead of torque - so the gearing gets taller and the thing gets "peakier". I personally can't stand the new Avalon, for instance. It drives like a Towncar - almost a binary throttle response because they are worshiping HP to beat the competition instead of just leaving it alone.

    Computer makers *finally* figured this out. Now we see a torque type race - same speed, but more cores and better multitasking. Graphic cards have been doing this for decades, though - raw speed is moot. How many pipes, buffers, and such makes the real difference.
  • rockyleerockylee Wyoming, MichiganPosts: 13,989
    Well they are only #1 for this quarter. I predict they will stay #1 but it's not set in stone yet until the final quarter sales come in. :P

    -Rocky
  • tjc78tjc78 JerseyPosts: 5,025
    "It drives like a Towncar"

    There are almost no similarities between the two. The TC is powered by a fairly sedate (230 HP?) V8 and has numb handling and steering. The Avalon for a big car handles fairly well and the engine is no comparison. If you want to compare the fact that they are both big quiet sedans, fine. However, the driving experience is totally different. And, for the record I have owned a TC and fairly often drive a newer GM which is basically the same thing.

    P.S. If you hate the Avalon and think it drives like a TC how come you always recommend the GM? It would stand to reason that you would hate that too.

    1999 Chevy S10 / 2004 Merc Grand Marquis / 2012 Buick LaCrosse

  • alexstorealexstore Posts: 264
    well look with your own eyes. put 2005 Honda accord and 2006 Sonata next to each other and look at them from the back.
  • captain2captain2 Posts: 3,971
    HP is nearly meaningless these days is because we have artificial limits on how fast we can go in this country
    now you know I can't let you get away with that one! :D The reason why an Avalon, let's say, will seriously outaccelerate a Lucerne in any measure (0-60, 45-65 or whatever) you choose, has nothing to do with a lousy 18 lb.ft. of extra torque it might have, but everything to do with the 70 extra HP it has. And it has everything to do with the fact that the Av engine will pick up revs (and HP) like no pushrod engine ever dreamed of. If you don't think that acceleration capabilities mean anything, everything is all about ultimate (illegal) top speeds, then you really need to drive that diesel E320 I waas talkng about - perhaps the ultimate illustration of what gobs of torque can do, while still watching the taillights of its gas engined counterpart.
    Nobody has yet to explain to me - why, if acceleration is all about torque, then why is there only a correlation between vehicle HP/vehicle weight and there is no direct correlation between between torque/vehicle lb. relative to acceleration capabilities. In summary, torque only 'gets you going' or FTM 'keeps you going' and will only provide that acceleration if the engine involved revs quickly - the definition of HP. Don't fall back on 'it's all about gearing' because within this class drive ratios are all similar, but the Avalon is in the next county 0-70 at 13 lbs/HP, the laggard Lucerne (at 19 lbs./HP) can't be seen in the rear view mirror. And both engines are spinning at about 2000 rpm at that speed (in top gear). And I would be willing to bet that you will find the same 2000 rpm at 70 or so in the Azera, the Maxima, the 300 V6, as well as the LaCrosse 3.6 - those cars all having reasonably good HP/wght ratios and what else? - acceleration capabilites (that has nothing to do with top speed) that the Lucerne 3.8 (or the 500) could only dream of.
    Besides which, if 'HP is nearly meaningless' then why do we even have 'HP wars' ?
  • joe131joe131 Posts: 972
    Yes, it IS all about TORQUE. Torque is force. Horsepower is torque over time.
    Remember, TORQUE is measured, HORSEPOWER is calculated by using the torque number. Without torque there is NO horsepower. But not the other way around.
    Torque is simply the amount of pressure created by a motor that tries to twist the crankshaft. It is force only. It is a static measurement. It is measured at a point in time, not over a moment, not a second, not over any span of time. It is measured as if the motor was not even turning over at all.
    Knowing the torque at any one point in time does not necessarily give you the ability to predict how quickly the RPM (speed) of a motor will increase because of that torque. There is no time component in a torque measurement so there is no uniform or predictable effect it will have (over a period of time) on the acceleration (which does have a time component) of the car. Torque does not concern itself with time in any way.
    But torque is all about the potential of a motor to begin movement of the car from its static position at a point in time at whatever RPM that torque value is measured.
    Maybe this, in conjunction with my previous post can help explain torque to you.
    Does this make sense to anyone out there?
  • kublerkubler Posts: 7
    It's almost correct, except that one needs to know the torque curve vs. rpm and the HP in order to judge the power of a car. The formula is torque = (HP * 5252)/rpm.

    If we look at a large waterwheel, we may find that turning at a leisurely 12 rpm and produce 2600 ft lbs torque! Using this formula we calculate that the wheel is only producing 6 hp!

    Therefore, we need HP and torque to move a car.
  • joe131joe131 Posts: 972
    Yeah, everything true that you said, I already said more than once in different ways. But what you added did not change anything I said. (What part do you think was incorrect?)
    And, like I've said, multiple plotting of torque vs RPMs is precisely how the horsepower curve is calculated. If you don't know torque at RPM then you can't calculate horsepower to begin with. Because a horsepower curve is only a mathematical derivative of the torque curve, the torque curve (which contains the time component in rpm) is, BY ITSELF, totally sufficient to judge the power of a motor. And if weight and gearing and other factors are known, acceleration and top speed of the car can also be estimated closely. Adding a horsepower curve to the graph is superfluous. It does, however, give the marketing department another more easily accepted and persuasive number to publish. A horsepower curve may also, to some anyway, more dramatically illustrate how peaky is the power delivery of the motor. So in that way the horsepower curve can be useful even though it is unnecessary. And sure, so long as torque does not drop off steeply (like it always does eventually), added RPM will result in increases in calculated horsepower.
    Again, horsepower is work/movement performed during time. Torque is force irrespective of time. Torque is force that has work potential but no movement.
    Waterwheel is just another example of torque and rpm being used to calculate horsepower. No news there.
    Say what you want, but if you ain't no way got no torque, you ain't no way got no horsepower.
    Got it?
  • plektoplekto Posts: 3,738
    P.S. If you hate the Avalon and think it drives like a TC how come you always recommend the GM? It would stand to reason that you would hate that too.
    ****
    Only because you can get one at the end of the year for about $17K. Dirt cheap for a relatively decent commuter-box.
  • captain2captain2 Posts: 3,971
    Only because you can get one at the end of the year for about $17K. Dirt cheap for a relatively decent commuter-box.
    truth to the old adage that you get what (you are willing to pay for)? The generally most expensive Avalon is BTW the cheapest car to own in this group (Edmunds and Intellichoice) and you are not likely to buy even a 'stripper' version for under about $25k. Perhaps you can explain that one, as you espouse on the virtues of antiquated (and cheap) cars?
  • plektoplekto Posts: 3,738
    I was talking about the GM. $17K after rebates at the end of the model year is common(about 18K right now via carsdirect).

    For that price, it's not a half bad car.

    I just don't like big, bloated things to drive. Cars are all so heavy now that it's like the 60s again. Bigger and bigger and more HP... And it all is just as horrid to drive.

    Give me a 2600lb little sports sedan and I'd be happy as a clam.
  • joe131joe131 Posts: 972
    If you don't have enough cash or credit to get an Avalon, the Crown Vic might be a good choice if you need a new big car. Not everyone has the means to buy or make payments on a 25 or 30 thousand dollar car. The Crown Vic or Sonata might be the best cars for lots of us who think we need a new car but can't afford the more expensive ones.
  • captain2captain2 Posts: 3,971
    OK that's fine but this is a LARGE sedans forum so therefore I must assume that your $17k 'bargain' must be an Impala with a 'really solid' (sarcasm intended) pushrod V6 in it. Same COO and value comments apply although the Impala is much closer to the Avalon in these regards.
    Would also suggest to you that as FE becomes more and more of an issue with the autobuyer, that this size boom that cars in almost all classes have unquestionably been experiencing, MUST slow down or even reverse. FE already sells, just wait for those gas prices to go up even more - we may all be driving diesels b4 you know it.
  • captain2captain2 Posts: 3,971
    The Crown Vic or Sonata might be the best cars for lots of us who think we need a new car but can't afford the more expensive ones.
    True, but if things are that tight that an extra hundred or even two hundred dollars or so a month, is going to make or break it - then I would tell you NOT to buy a new car at all. That CV or Sonata a year or two old - now that would be cheap. Or conversely, you could drive something a whole lot better, let's say that Avalon you couldn't afford to buy, on a lease for possibly even less money than had you bought (or leased) either of the other two cars.
  • joe131joe131 Posts: 972
    I covered that, and its up to them whether they get a new one or not.
    New cars are often much better deals than used cars cuz used prices are so high. most people selling nice newer ones are upside down and can't afford to see them for a fair price.
    Good to amazing incentives and loss leaders on new ones sometimes and loan rates lower on new too usually. And the better warranty might pay off over a used car.
  • captain2captain2 Posts: 3,971
    those end-of-year clearance prices very rarely do anything but 'screw' those buyers that bought the car earlier - in resale values. 'Program' or lease cars dumped back onto lots can be very reasonably priced, and usually are both low mileage (with warranties remaining) and well maintained simply because those are the terms of leases. An 06 Taurus right off the Hertz lots can currently be had for about $11k with something under 20k miles on them. Don't think there is a more defendable choice, value wise, than buying any car (Avalons included) after somebody else has taken that first and/or second year depreciation hit. To purchase a new car is certainly a luxury that all of us can not afford, but when we do, I think it is important to understand that cheaper up front does not necessarily mean cheap to own.
  • joe131joe131 Posts: 972
    I already explained: cheaper up front is the only way some can afford to get a car, regardless of true cost to own over the years. And that goes for used and new cars.
    With maintenance costs high for parts and labor ($105 per hour in many cities) that first 20,000 to 30,000 miles while under warranty might be the cheap miles in spite of the new car depreciation. And if you get a LOT of incentives when buying new, the depreciation ends up being much less than if you paid whatever most people paid for the same model year car.
    I had a brand new 1996 Ford and its transmission self destructed EVERY 20,000 miles. I sold it when it was on its 3rd transmission and second motor. It had 58,000 miles on it. Best $800 I ever spent was on the $0 deductible extended warranty I got from the credit union lady. OVER $10,000 in major defect repairs in under 60,000 miles.
    But I bought it WAY under INVOICE and sold it privately for a good price so cost to own was not so bad. Time in shop was inconvenient, but I got a free rental under that warranty too. Over the years I've had total failures of 5 Ford transmissions and ZERO for all other brands. Fords have made up 20% of all my cars.
  • barnstormer64barnstormer64 Posts: 1,106
    If your car starts going slower up the hill as it goes on, you'll eventually reach a speed where it will more or les keep the same speed despite the accelerator being floored.(half throttle or full - hardly any differnece) You may have 200+ HP, but you ran out of torque.

    Nope, you ran out of horsepower. Either that, or you ran out of gear ratio (which affects torque at the WHEELS).
  • barnstormer64barnstormer64 Posts: 1,106
    It's as simple as that: Acceleration is directly proportional to force (i e torque at the driving wheel) and inversely proportional to mass.

    You forgot about pulleys!

    If you want more torque at the wheels, just apply a different gear ratio. That's what they're there for.

    Just like a pulley system allows you to lift more weight than you can with a straight lift. Or a lever. Remember the statement "give me a long enough lever, and I can lift the world"?

    Granted, you'll have to pull the rope twice as fast on a system of pulleys with a 2x mechanical advantage . . just like you'd need to get twice the rpm if you changed the gearing 2x. Either way, it's WORK (or HP) that keeps you moving/accelerating.
  • barnstormer64barnstormer64 Posts: 1,106
    the torque curve (which contains the time component in rpm) is, BY ITSELF, totally sufficient to judge the power of a motor.

    Not true at all. That only tells you how much the engine can "lift" . . but not how fast it can do it.

    What if the engine has gobs of torque, but can't exceed 1000 rpm because it get "winded"? That means it has very low HP . . all the torque in the world isn't going to help it . . unless you don't mind simply lifting heavy stumps out of the ground, instead of using it to power a vehicle.
  • jim101jim101 Posts: 252
    Ran out of torque, hmmmmmm, ja ever consider that maybe the catalytic converter might be dirty and or need replacing. As they become clogged they rob horsepower and torque.
  • bhmr59bhmr59 Posts: 1,598
    Who are you to decide an an extra hundred or two hundred bucks or so a month should determine whether one should be able to buy a new car?

    My property taxes went up $130 per month, electric bill will double from January to July (~550 Kwh just over $100), cable bill up $22/ month, gasoline $3.159 (up from $2.949 a week ago). Property taxes will go up about $280 on July 1.

    Different areas of the country have different costs of living and affect people's disposable income. Just don't give us the "only" $1 or 2 hundred bucks a month stuff.
  • joe131joe131 Posts: 972
    I think if you read my previous posts more carefully, you will understand why your post is wrong, but I'll repeat some of the info here for you in a little different order and using a few simpler words in another attempt to clarify it.

    I'll comment on your post from finish to beginning.

    Last you ask, "What if the engine has gobs of torque, but can't exceed 1000 rpm because it get "winded"?
    Read the answer here, ok? If the engine cannot exceed 1000 rpm then the graph of torque vs rpm (the torque curve) will reflect that. The curve will end at 1000 rpm. The calculated horsepower curve will also end at 1000 rpm since that is the maximum speed of the motor.

    Previous to that you guess that the torque curve only tells you how much the engine can "lift" but not how fast it can do it.
    Now why you bring that up I do not know. I never claimed the torque curve alone can tell how fast an engine can lift anything. And, by the way, in spite of your notable imagination, a horsepower curve does not tell you how fast an engine can "lift" either.

    And lastly, you first state that the torque curve by itself is NOT totally sufficient to judge the power of a motor.
    The answer is, "Oh yes it is!"
    Heres a reminder for you: Horsepower is just a label. Torque is also a label. A torque curve is a representation of measured torque over the rpm range of a motor. A horsepower curve is calculated from and totally dependent on the values in the torque curve being applied in a known mathematical formula. The label of force relative to rpm is thereby converted from the torque label to the horsepower label. There is NO additional information magically imparted to the graph by simple mathematical manipulation of the plotted points on the graph which compare force measured at different rpm levels. And before you can calculate horsepower for any rpm level, you must first measure torque at that same rpm value, then convert torque vs rpm to the horsepower label using the formula.
    The addition of a horsepower curve ONLY gives a more dramatic profile of force at rpms and adds another label on the graph.

    I understand your frustration in wanting to see a representation of how much time it takes for a motor to increase its rpms (or torque or horsepower), but the type of graph mentioned above (one containing torque and/or horsepower curves over rpms) just DOES NOT provide that information, whether labeled as either torque or horsepower plotted against rpms.

    To see the rate at which torque/horsepower/rpms values change, which is to say the time span over which a measured value changes, another meter of time in seconds/minutes/whatever would need to be calibrated across one axis of the graph too.

    The simple and most meaningful graph to represent how the power of a motor actually moves the car is to plot an acceleration curve for the whole car as it powers away from a stop up to its top speed. That calls for a stopwatch and a road test, well beyond the capability of a dynamometer (engine brake) machine.

    If you only really wanted to know how quickly a motor can rev up under whatever load, you could do that on a motor test stand. You'd need to connect the crankshaft to a tachometer and use a stopwatch to measure how long it takes for the motor's rpms to change from one level to another while applying your choice of loads resisting the rotation.

    Either way, you MUST add another measurement to the test. And that measurement is elapsed time which can easily be counted with a stopwatch.

    OK now?
  • captain2captain2 Posts: 3,971
    What if the engine has gobs of torque, but can't exceed 1000 rpm because it get "winded"? That means it has very low HP . . all the torque in the world isn't going to help it
    Exactly
  • hjc1hjc1 Posts: 183
    Enough is enough.....I think we talked this issue to death.
    All I know is my Azera gets me from point A to point B with no problems :=)
  • joe131joe131 Posts: 972
    And 2 + 2 = 4. Glad you can count. Big deal! So what?
    Simple math there, guy.
    High torque, low rpm motors exist, like in the over the road tractor-trailer rig mentioned before.
    So a motor that makes 2000 ft. lbs of torque at 1000 rpm also makes 381 horsepower at 1000 rpm. Big deal! So what?
    Torque and horsepower, may they rest in peace.
    And may we too?
  • imidazol97imidazol97 Crossroads of America: I70 & I75Posts: 18,263
    >You'd need to connect the crankshaft to a tachometer and use a stopwatch to measure how long it takes for the motor's rpms to change from one level to another while applying your choice of loads resisting the rotation

    That measurement would be meaningless because the motor has to turn the transmission input shaft and the car's mass is connected to that. In other words more torque will start the car moving better and speed up the car quicker to get to the next gear change to effect the same cycle again.

    Speeding up an unloaded motor is useless data.

    This torque vs. my car makes 350 horsepower so it's better spitting match has been boring for the last many posts. I can imagine new visitors reading this and leaving in droves saying, "I don't wanna be in an arguement..."
  • plektoplekto Posts: 3,738
    My point earlier was that while MY vehicle doesn't run out of speed necessarily, all of us have had the situation where we are going up a long hill and it starts to struggle. If you wanted to pass/change speed, you whomp on the pedal and virtually nothing happens.

    That's torque. Going 60mph up a hill and wanting to go 70 - but the throttle just does nothing... You ran out of it/don't have enough. Going 1500rpm in overdrive just makes it worse as it takes time for your engine to spool up to where it's developing enough HP(or you can downshift hard, but that's a poor excuse when the engine supposedly has 250+HP) (GM and Ford are famous for this "wide-open-throttle-lag" scenario, thanks to their transmissions being so tall and the torque converter being so agressive)

    Now, sure, you *do* accelerate, but it's a slow roll-on instead of pushing you back in your seat and jumping NOW for that open spot in traffic.

    What is optimal is when the two values are roughly the same, of course(or what I and others call a "square" engine) So, for instance, a little VTEC with 200hp and 120lb-ft of torque isn't going to drive in traffic any better than a stock 140hp motor with the same torque. Oh sure, on the highway or on a track, it's a whole other animal, but slogging through traffic going 20 to 40 to 30 again - you'd be hard pressed to feel a difference. But a 180lb-ft/180HP engine will drive much quicker despite not having as much HP.
  • martin22martin22 Posts: 53
    FYI a "square" engine is one whose bore dimension is equal to its stroke dimension
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