Prius Eco 58 MPG vs Prius 54 MPG - What's the difference?

Discussion in 'Gen 4 Prius Fuel Economy' started by cyclopathic, Nov 18, 2015.

  1. bisco

    bisco cookie crumbler

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    that what i was afraid of.:unsure:
     
  2. Netcub

    Netcub Active Member

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    It is puzzling with the weight issues... Sometimes it seems with my hatch full, and seats folded down with a few hundred pounds of weight, I can get 62 mpg on my commute. (Highway going 55) I can come home, empty the car completely, and get 52 the next day on the same exact trip...
     
  3. pmike

    pmike Member

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  4. giora

    giora Senior Member

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    How do we know Prius is becoming mainstream? Car magazines start to treat it seriously.(y)
     
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  5. cyclopathic

    cyclopathic Senior Member

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    That explains it! We just replaced Enasaves on sons Mirage with RT-43s and MPG went down from 51 to 44 MPG. Enasaves great MPG tire, better than Energy Savers, but it handles like crap. I think skidpad rating is 0.73 vs 0.8 for Energy Savers or 0.86 for TrueContact.
     
  6. GasperG

    GasperG Senior Member

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    I assure you that variation in MPG between different tires is nowhere near your preposterous 16%. I have been driving on one of the most fuel efficient tires (Ecopia EP001s) for 36k km and even if I compare MPG against fresh winter tires, the difference is in maybe in the 5% region (I'm talking about same tire size).
     
  7. cyclopathic

    cyclopathic Senior Member

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    Normally difference would be 2-3MPG, at least that what it was going from Ecopia EP20 to Michelin Energy Savers on Gen3. If you take lesser extremes you are looking at 0.5-1MPG tops.

    We do not have EP001 in US, the best LRR sold in US so far is Michelin Energy Saver (in EU label rated economy B vs A for EP001). Irregueardles I think Enasaves will eclipse Energy Savers. I can't run direct comparisons due to size availability, and could not find any EU label for Enasaves, but they will be rated C or below on grip, and likely A on efficiency. At least in Japanese rating both EP001s and Enasave 01 rated as AAA economy, and A vs C in handling.

    General RT-43 is not sold in EU but the models sold in EU are all efficiency rated F or E in some sizes, and the difference btw A and G is 7.5% in consumption. Add the effect of new tire (the difference in rolling resistance btw new and old tire ~20%), and drop wouldn't look so unrealistic.

    But I stand by my statement above: Enasaves are very efficient tires with very crappy handling, at least in 165/65 size. It may be slightly better in 195/65, but after driving them for several hundred miles in various conditions I can attest they will be off within the week of getting car. They make EP20, FuelMaxes look like ultra-performance offerings.
     
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  8. Trollbait

    Trollbait It's a D&D thing

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    The missing piece.
    The ECO loses some weight. The rear wiper delete can also help a little with aerodynamics. The Li-ion likely improves regen braking efficiency. And now tires with lower rolling resistance and higher set pressures.
    It isn't just tires. Setting the pressure 3psi higher than the other trims can have a big difference. My Sonic can lose 2mpg when the tire pressure drops below 40psi.
    It comes down to the roads on your commute. The higher momentum from the extra weight can help reduce the require energy input from things like rolling hills at steady highway speeds. But you also have to account for other daily variances like temperature and wind direction.
     
  9. GasperG

    GasperG Senior Member

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    Tires in US and EU are usually very different, we almost don't' have all season tires, the ones we do have (5 models) are more of a winter tires than US "3-season". Energy saver in EU is completely different tire, I had them on other car and they were the worst tire in the wet. EU rating is only made on tires sold in EU, and also those ratings are getting in similar direction as NEDC, if you know what I mean. Ecopia EP001s performed very good in the wet til the point where I had to throw them I logged 0.9 G braking force in the wet.
     
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  10. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Not trying to be difficult but wondering:
    What source or how was this measured against other tires?

    At one time there was some buzz about California and/or NHTSA doing some tire rolling resistance measurements but it died down (or went somewhere I've not yet found.)

    Bob Wilson
     
  11. Mendel Leisk

    Mendel Leisk Sand Pounder

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    Sounds like mpg trumped everything, the eco model is their sacrificial lamb.
     
  12. pmike

    pmike Member

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    The only thing I can think is that they need the ECO model to make their marketing claims and just throw all the others in the same MPG rating for simplicity or cost. I would imagine the best to worse gas mileage goes as follows: Two ECO, Three, Four, Two, Three Touring and Four Touring. I would think the biggest differentiation in MPGs would be 15" versus 17" and the Ni-MH versus Li-ion.

    Probably the biggest thing that caught my attention was the vastly increased driving dynamics though significantly increases structural rigidity and the change in suspension in the rear.
     
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  13. cyclopathic

    cyclopathic Senior Member

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    Looks so.
    With Gen3 we got Two and were happy with it. Now on Gen4 Two would not cut b/c of the NiMH battery, MPG and mostly IR block (lowE) windshield. Gen3 dash is sun magnet we were forced to run A/C in sunny 78-80F temps due to solar gain. If they got MPG by installing Enasaves, dropping spare tire and removing rear wiper, than no we don't want that. I wonder if Gen4 Three has lowE windshield.

    Tirerack did some testing a while back: Tire Test Results : When Round and Black Becomes Lean and Green, and they usually post MPG difference for tires tested. But most likely if you if you are trying to compare tire A to tire B it is not possible, you just need to compare A to C, C to D and D to B or something like this to get some idea on how tires stack.

    Personally I don't have opportunity to run multiple tires, but F8L ran the LRR tire list thread, check it out.

    I had used some of the "recommended" LRR tires, and some of them were true and others gimmick. For example EP422 economy was barely improvement, just above threshold. Energy Savers gave good boost, and they last longer or about what they are rated at. Their weakness is sidewall cracking after 2-3 years, cost and very mediocre snow handling. Wet handling isn't great but ok as long as there is enough thread left. Generals RT43 were tested by Consumer Reports and they found them to be better than average. They are very cheap, long lasting and good grip for all-season tire. They are very good value b/c with many LRR tires

    I wish FHWA or EPA had adopted EU or Japanese labeling system, so you could look at the label and make an informed decision on what to buy.
     
  14. Gokhan

    Gokhan Senior Member

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    Not having spare tire = Having to have your car towed when you have a flat = Not acceptable

    (Fix-a-flat wouldn't work in most cases when your tire/wheel fails.)

    So, if I bought any car without a spare tire, I would pay extra for one along with the jack and tools.

    It's a mystery why the Prius Eco MPG leaves the vanilla Prius MPG in the dust. Would any hardcore Prius fan want to get the vanilla version knowing that the fuel economy is so much worse? Then there is the dilemma that the Eco version lacks some goodies to cut the price tag.

    Corolla Eco uses an upgraded engine in comparison to the vanilla Corolla. The upgraded engine has the Valvematic technology that the vanilla engine lacks, which substantially improves the fuel economy. I don't know if this is the case for Prius Eco.
     
  15. pmike

    pmike Member

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    Guess we won't know Two versus Two ECO value difference until we get some rear world MPG numbers. If the handling difference between is a much as they say it is between the 3rd and 4th gen then that would make the Two valuable to me. The spare is the only "missing" item I would be concerned about. I am in Florida so the rear wiper is of no value to me. If I were to buy a 4th gen I would get the Two ECO just for the fancy new Li-ion. Based on the info I have found it appears what is making the MPG difference between the Two and Two ECO is the better battery and better tires that are inflated a bit more. I wouldn't value the claimed/posted number since they cover so many different models that should show a 2-3mpg difference just due to the 15" to 17" tire difference.
     
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  16. GasperG

    GasperG Senior Member

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    Fix-a-flat works in most cases but not all, it's good enough for me.
     
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  17. Zythryn

    Zythryn Senior Member

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    Tires are part of it, but don't forget the Li batteries. Additional regen is a good chunk of that in city driving as well.
     
  18. cyclopathic

    cyclopathic Senior Member

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    I will reserve the judgement until I get to drive Gen4, but I seriously doubt Gen4 is much better than Gen3 in handling department. This will get slammed but here are the reasons for my doubts:
    1) Gen3 has horrendous understeer and body roll.
    2) Gen4 had lowered CG, so body roll will be less, but once again this does not translates into less understeer
    3) Gen3 understeer issues were in front; going to fully independent rear suspension does not improve front. It actually makes understeer worse.
    4) Toyota's philosophy on suspension design is "safety first", and it is across the board and will not change from one model to another. They designed front suspension with large negative scrub radius. Safe in case of brake/tire failure, strong self-centering when hit pothole/ice, no torque steer and huge understeer.
    5) CR(?) tester drove Gen4 and found it an improvement comparing to Gen3, but still behind Ford Fusion. Needless to say Fusion is the 2nd best handling midsize car on the market, even Mazda6 (which in my opinion barely acceptable) or more premium german offerings are better.
     
  19. bisco

    bisco cookie crumbler

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    but they all have lion except pkg II.
     
  20. cyclopathic

    cyclopathic Senior Member

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    Really interesting to see detail specs. Very possible since Corolla uses the same 2ZR engine as Prius. I think Gen3 is using only VVT-i, so Valvematic, though it is tuned differently on pseudo-Atkins implementation
     
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