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Prius acceleration characteristics off the line compared to conventional engines and transmissions

Discussion in 'Gen 3 Prius Main Forum' started by briank101, Jun 26, 2014.

  1. briank101

    briank101 Member

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    I contend that the Prius accelerates like a V8 from 0-15 mph, like a V6 from 15-30 mph, and like a 4 cylinder from 30 mph onwards? Also at any speed below 50 mph would it be fair to say that the first second acceleration response when quickly floored is more instant than the majority of ICE engine (if not put in a lower gear beforehand). So what I'm getting at is that Prius has a more practical delivery of instant acceleration in every day driving particularly below 50 mph and above 50 mph so what if it takes me a second or two more to get to 70, after all I'm sharing the highway with trucks and most other drivers that seldom need to demonstrate their egos and that the 0-60 mph tests where they hold the engine at 5000 rpm + before starting the stopwatch is akin to a theoretical exercise that gives a good number on paper but not practical for everyday driving and likely detrimental to engine longevity.
    I base the above on accelerometer measurements with all cars stopped with ICE at normal idle speed for the non-hybrids. The Prius has far more linear acceleration than the ICE-only cars due to both having conventional transmissions that sometime have a lag and the fact that the engines that need to rev high to deliver good off-the-line acceleration although that acceleration is a highly peaky curve, that has a high variation in thrust delivery due to gear changes and variations in engine speed. After my teen years (nearly 30 year ago) I'm no longer a fan of engines that need to rev high (like you stole it) to deliver faster acceleration, I am also not a fan of vehicles that take time to downshit 2 or 3 gears before they come to life, which is why I becoming a bigger and biger fan of my Gen III Prius as each day goes by. Conventional engine and transmission cars feel more and more unrefined and which is why people who drive pure electrics a Tesla or even hybrids like the 2012 Camry Hybrid are often forced to rethink their notions of electric or hybrid-electric propulsion. Remember low-end torque is low-end horsepower and low-end horsepower is what you can tap into every single day, high-end horsepower (after the engine has revved up and the transmission downshifted) is what you'll tap into when your ego is low and when you feel like showing off because making a lot of engine noise is what really gets the attention.
    It's interesting how many motor journalists put the majority of their scoring on the aspects that will be utilized less than 1% of the time. If car X is 0.8 g in the skid pan and has 280 peak hp, these attributes will be emphasized far more than comfort (which impacts you all the time) and off the line acceleration which impacts you everytime you come to a stop. Engine noise with pedal to the floor at 70 mph is a far less important consideration to most motorist compared to engine noise when accelerating from stops and requiring punchy refined acceleration in normal everyday stop and go commuting which is where most of the time will be what's judged.
    The Prius for me gives the right balance of the above when figuring overall value for money. The Camry Hybrid would be second. And if I could leave the cost aspect out, it's the Tesla S hands down. I think in twenty years, the majority will be thinking, how did we put up with those noisy unrefined engines and transmissions for so long. Kind of like how people look at 480i picture quality now after getting used to HD.
     
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  2. jonb505

    jonb505 Member

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    Agree. I drove a rental mitsubishi outlander v6 once(my entire history of daily drivers has been sub 2 liter 4 cylinders). In normal driving it felt just as slow as any other car. only when i stomped on it did i notice the overwhelming v6 power that only really kicked in once i was past the legal speed limit, but off the line it was as sluggish as any other conventional vehicle with an automatic transmission.
    In everyday city stop and go driving with my prius v if i max it out in the eco zone on the HSI when the light turns green i am the first off the line 99% of the time. Sure, it only takes a second or 2 for the other cars to catch up and pass me if i stay in the eco zone but i still feel quite proud of myself for those couple of seconds. :D
    This instant acceleration does have its drawbacks. Driving in light rain today in city traffic on my way home, waiting to turn right at an intersection i attempted to accelerate quickly into the lane before pedestrians started crossing, too much torque/wheelspin, traction control shut me down before i could even move, had to wait. (n) Maybe my michelin energy savers are getting a little thin on tread, but i've noticed a profound lack of grip in the rain trying to accelerate from a stop, even before the gas engine kicks in the traction control will shut me down quite often. It is an odd sensation to have the wheels spin/traction control engage without the sound of the engine revving like would happen in a normal car.
     
  3. bisco

    bisco cookie crumbler

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    second that.(y)
     
  4. cycledrum

    cycledrum PSOCSOASP

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    The Consumer Reports 'New Car Preview 2011', ISSN 1556-3267, P. 184 lists ...

    Rav4 Limited with 3.5 L V6 engine at 2.6 sec 0 to 30 MPH, 6.7 sec 0 to 60 MPH

    Prius Four at 3.7 sec 0 to 30 MPH and a lackluster 10.6 sec 0 to 60 MPH

    --------------------------

    For normal driving, Prius seems to have pretty 'leisurely' acceleration, as they (journalists) say.
     
  5. Troy Heagy

    Troy Heagy Member

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    Try driving a diesel sometime. I routinely spin the wheels even on dry road. :) The reason Prius and other hybrids feel strong off the line is the same reason my diesel spins it wheels: high torque.

    The electric motor provides max torque at idle, where a gasoline engine does not reach max torque until 4000 rpm (typically). The curve below shows the Honda Insight is pretty weak by itself, but the electric motor adds almost 30 more Nm of torque at idle. A prius would obviously have more.....

    [​IMG]
     
    #5 Troy Heagy, Jun 29, 2014
    Last edited: Jun 29, 2014
  6. A617

    A617 Member

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    Owning and driven a diesel I agree that it accelerates like one, in comparison to the prius its like a old 1.9L ALH 4 cylinder TDI which only has 151 lb/ft and 91 hp its starts strong having all its torque around 1900 rpm and the power begins to go flat 3000, and at 4000 rpm you can actually feel your loosing power. Yes the prius dose start its max torque at 0 rpm thx to the electric motor however since our engine is an Atkinson cycle engine and having a eCVT that is causing a lot of parasitic loss is why we don't get much power in the top end, it would be nice if they would add a clutch pack of some sort to have direct drive to the wheels, but this will come at a cost of MPG/efficiency.
     
  7. retired4999

    retired4999 Prius driver since 2005

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    Hummmmmmmmm! Back in the 60's 10.6 was pretty fast!...............:rolleyes:
     
  8. Troy Heagy

    Troy Heagy Member

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    Yeah I think people saying "10 seconds is slow" are nutters. You don't need a lot of acceleration to merge onto an interstate. I've done it with an old car having only 15 seconds acceleration & it was a piece of cake. The government provides lots of ramp to get up to speed & merge between other cars.
     
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  9. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    I ride motorcycles and drive cars....including a 2010 G3.
    Like many things in life....acceleration and speed are subjective...not objective.

    My 09 Vulcan 900 is a very under powered bike. (about 55-BHP)
    A Z-06 could probably stomp a mud-hole in my butt from light to light if you took out two of its sparkplugs.
    But compared to a Prius?
    It's a fire-breathing, tire smoking monster. :eek:

    There is no doubt that a Prius is adequately powered enough to pull interstate duty, or drive just about anywhere in public traffic including LA and Hotlanta---two places that I can routinely see triple digit blasts and 5-mph crawling in the same afternoon trip.
    I also have a golf cart (a 14 year old EZ-GO txt) that actually feels kind of spirited from zero to about 5-MHP.
    You get that same kinda vibe in my G3, when you're WOT sprinting from a stoplight while the cell phone queens and GPS jocks are still diddling with their portable electronics and yelling at their kids in the back....
    However (comma!)
    In my never-to-be humbled opinion??????
    10-seconds from zero to 60?

    Slow.
    As.
    Hell.

    I routinely stomp on the accelerator pedal in my G3 while wishing that there was some kind of beneficial piezoelectric effect similar to my jabbing a button a little harder on a remote, or mashing an elevator button a little harder trying to get a little more response out of a machine that is already running as fast as it is going to go.

    Sometimes?
    When I'm driving home from work, I'll do a WOT launch from an intersection in my pickup......just to feel and hear the difference that a(nother) slow vehicle will make in going from zero to about 45----only in the case of my truck, a vehicle that has 315BHP and can lumber its way up to 60 in a little bit less than 10 seconds.

    Like I said.
    Priuses are perfectly fine and indeed fast enough for normal driving. Mine in fact, will go significantly faster than my 315BHP pickup truck----provided where they're governed by the OEMs.

    But 10-seconds????
    Yeah.
    It's SLOW,


    YMMV! :)
     
    #9 ETC(SS), Jun 30, 2014
    Last edited: Jun 30, 2014
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  10. Troy Heagy

    Troy Heagy Member

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    As you said: It's perception. (shrug) My prius is faster than my Honda two-seater. It doesn't "feel" faster than the high-revving Honda, but the prius reaches 60 about half-a-second quicker.
     
  11. TomB985

    TomB985 Member

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    Yeah, I have to disagree with the premise of this thread. Yes the Prius has perfectly adequate acceleration, but I have never driven a slower car in my life. The 4-cylinder Chevy Malibu we used to have at work felt livelier from a stop than my Prius does. And that's fine, because I didn't buy the Prius for performance.

    And I guess you'd call me "nutters" Troy, because I think this car is really slow. But I didn't buy it to race with, so I'm happy with a slow 50 MPG. :)
     
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  12. The Electric Me

    The Electric Me Go Speed Go!

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    Here is my "subjective" feelings.

    I LOVE the way my Prius accelerates. From a stop, it's so much quieter and "smoother" than the majority of ICE and regular transmission vehicles.

    Now when I rent, or drive almost any "regular" vehicle, it seems uncouth and unrefined.

    BUT...I'm NOT going to say my Prius accelerates like a V8 from 0-15 mph. Because, IMO despite the "instant" torque of the electric motor, it simply does not.

    The electric motors, might provide "instant" torque, but I think that instant torque is so limited in translatable power that what you get is more of a refined and controlled acceleration. One I have come to enjoy and like....but not one I am going to mistake for being a V8 engine off the line.

    I've said it in other threads, but I think promoting HSD and Prius as being powerful or fast off the line? Is misleading.

    If you buy a Prius thinking you are going to win a lot of drag races...even drag races just 0-15 mph? I think you are going to be disappointed.

    If you buy a Prius thinking you will accelerate smoothly, quietly and more efficiently than most vehicles off the line? Then you have a winner.
     
  13. Regular Customer

    Regular Customer New Member

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    Are people actually trying to go 0-60 in Eco mode? When I need to do that, I use Power mode and short on ramps are a breeze. Sure I could floor it in eco mode but why bother when I have to wait for the computer to figure out what I want to do when I already know?

    So much of the acceleration behavior in modern cars is due to the manufacturer's algorithm for what they want that particular model to do. The Prius gives you more options than most, but even the default is different from year to year. The 2010 Prius and the 2014 Prius are both Gen III but the default acceleration behavior is different between the two. The typical leadfoot/brainoff driver will get better mileage from a 2014 versus a 2010 because Toyota seems to have found a sweet spot for the default algorithm. You can figure out how to use the throttle to your best advantage by a combination of foot action and mode switching, but don't expect auto reviewers to spend that much effort on figuring that out - they're spending only two hours with a car and looking at dozens of characteristics of the car besides just the throttle/acceleration; most of them want the throttle to work the way they want it (whatever that is, they never say exactly and certainly don't examine why) and complain when they get something different. If someone's not basing a review on at least 10K miles of driving the vehicle, it should be taken with a grain of salt. Most drivers are driving by feel rather than by data - people drive on the interstates at the speed the car "feels comfortable" rather than what the speedometer says and the combination of what their skills + the car's capabilities are.
     
  14. mmmodem

    mmmodem Senior Taste Tester

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    Maybe something is wrong with my car? There is hesitation from 0-15. Its slow from 15-30. And from 30 on, it's one of the slowest car I have ever driven. Even my friend commented on it when she drove it. I had it in PWR mode and she said acceleration was just good enough if it wasn't for the hesitation at take off, it would be perfectly acceptable.

    The hesitation from what I gather is the time it takes for the ICE to fire up to provide the boost. I hardly notice the instant torque.

    I mean if you guys think its a V8 from 0-15, then it must be a V10 with twin turbos on a PiP in EV boost mode.

    SGH-T399 ?
     
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  15. briank101

    briank101 Member

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    What helps if waiting at a red that's about to turn to green, is have the left foot on the brake, and your right foot slightly touching the accelerator, (equating to about 200 watts or 1 Amp increase on battery draw in Torque app). This ensure any slack in the system is taken up and instant off the line acceleration without any shocks in the final drive ratio gear cogs. Haven't once not been off the line first with this method, unless I was distracted. Nice thing about a Prius when doing this, unlike conventional cars/transmissions, is the minimal impact on engine/transmission longevity. For convention automatic cars to be faster, they would need to hold the brake strong while holding engine revs at a high level. For manual, dumping the clutch with high revs is required. None of which should be preformed on a regular basis if one wants longevity in their engine/transmission.
     
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  16. tpenny67

    tpenny67 Active Member

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    My weekend driver is a V-8 Mustang, and there's no comparison between the two. If you stomp on the Prius it may give a small chirp of the tires from a dead stop, but otherwise goes about acceleration calmly and without drama. It's a car that feels slower than it actually is.

    By comparison, the Mustang is rather dramatic from a stop with a V-8 snarl, spinning rear wheels and some sawing at the steering wheel trying to keep it pointed straight ahead (got one of the last ones without ABS :). It's actually a bit slow by today's standards, but if you want torque and the ability to go 80 uphill in top gear, this is where you'll find it. It's a car that feels faster than it actually is (less horsepower than a modern V-6 Camry).

    That said, the lack of drama makes the Prius better at turning onto busy roads. Spinning the back tires isn't as much fun when there's a truck doing 50mph that you're trying to pull in front of.
     
  17. lar.smith42

    lar.smith42 Active Member

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    I have a 2010 Prius ll. When I put in PWR mode and stand on it there is no hesitation. It gets up to why speed a lot faster than my 2004 Honda CRV ever did!!!!
     
  18. briank101

    briank101 Member

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    Actually the issue with conventional cars is that they're more likely to cause the wheels to spin due to their peaky power delivery. Google "Tesla Model S vs BMW M5 Drag Race" video, and you can see how the torque of an electric motor can finely stay just right below the limit of the tires' coefficient of friction, maximizing the acceleration from the limited traction. Yes having all traction from an electric motor would be the ultimate for me, but the Prius for now, is my bridge to the future when electric traction may be more widely adapted and accepted. The Tesla is helping in this regard. Now it would be nice if they had a 100kW motor option in the 4th Gen Prius or 60 kW up front and 40 kW in the back (if they happen to offer AWD), to win over those that think the Prius is a golf cart.

    Or...How about a radical idea, 2 power choices!!!!!. 60 kW for the traditional Prius buyer, and a 100 kW motor for those potential buyers that have up to now avoided the Prius for the "golf cart" image, as some portray. Hey, Toyota already have something like this off the shelf, the Camry hybrid unit. I wonder if the 1.8 engine teamed with the Camry motor, and battery pack/inverter could be made to work well.

    Anyway as I've said before I'm pretty happy with the way the Prius accelerate in city type driving which is 95% of my driving, and as far as I know I can accelerate pretty hard day in, day out with much less impact on engine/transmission longevity than regular cars. Now if they could sound proof the engine more so it's even quieter at high revs, and we wouldn't have all those journalist complaining of its noise when doing 0-60 test.
     
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  19. Agent J

    Agent J Hypoliterian

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    It's a bit of a cheat, but I have a technique that works for me on stoplights that i'm familiar with the timing sequence. The result of which will leave almost everyone behind until i reach the speed limit. I just fall back half a car's length from the line, and with careful timing from the opposite light turning red and its gap to the lights in front of you to turn green, i just do a rolling start so that as the lights turn green, i already have a head start of half a car and all that torque available for me the moment i mash the pedal. All the rest behind me are still starting to accelerate.

    I only do it especially when there's a show-off in a V8 in the other adjacent lane who couldn't see me doing the jump start. :p It just sends them backing off the moment they see a Prius out-accelerate them off the line.
     
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  20. Stratman

    Stratman Member

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    To me the acceleration is strongest between about 10 and 30 mph. From a dead stop, the hesitation of the ICE kicking in makes the Prius feel like a 4 cylinder momentarily sputtering from a misfiring cylinder or carbarator in need of rebuilding.

    There is nothing remotely "smooth and quiet" about a Prius accelerating from 0. More like hesitate, quick shutter, then slight jerk forward. Probably my biggest complaint about the car. Driving in Atlanta makes it a constant nuisance.
     
    #20 Stratman, Aug 9, 2014
    Last edited: Aug 9, 2014