Question-2025 Prius in EV Mode: Reply quickly!

Discussion in 'Gen 5 Prius Technical Discussion' started by iRun26.2, Jun 13, 2025 at 6:28 PM.

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  1. Gokhan

    Gokhan Senior Member

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    That (4.4 mi/kWh) is actually dismal, let alone impressive.

    I routinely average around 6.5 mi/kWh in the city with my 2021 Prius Prime Limited. I can average 6.3 mi/kWh on the highway if I keep the speed at 55 mph or below. My record in the city was 8.1 mi/kWh (round trip, 25 mph).
     
    #41 Gokhan, Jun 16, 2025 at 8:37 PM
  2. iRun26.2

    iRun26.2 Active Member

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    I have the most advanced models and it is rated as having less range than the cheaper models. Probably the more expensive models are both heavier and more wasteful of electricity because of the added functions.

    In any case, if I can get 4 miles / kWh , that still amounts to greater than 40 miles EV, correct? I find it confusing when the battery capacity is stated like 13.8 kW-hr yet the battery is claimed only used down to 25% (how many real kW-hr do we really get)?

    I am greatly looking forward to driving to work on Wednesday. This will give me a good idea of what time I can expect in the intended use for EV
     
    #42 iRun26.2, Jun 16, 2025 at 9:01 PM
  3. Gokhan

    Gokhan Senior Member

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    The EPA formula is:

    Useable BEV battery capacity at the 240-V plug (kWh) = 33.705 kWh/ge × BEV range (mi) / mpge
    Useable BEV battery capacity at the battery output (kWh) = ~ (0.90 to 0.95) × 33.705 kWh/ge × BEV range (mi) / mpge

    0.90 to 0.95 in the second formula is the charger efficiency.

    The car displays the kWh at the battery output (not the 240-V plug).

    You can plug in the EPA numbers to the formula to get the mi/kWh on the car display. Basically it is mpge divided by 33.705 and then divided by (0.90 to 0.95).

    mi/kWh at the battery output = (mpge / 33.705 kWh/ge) / (0.90 to 0.95)

    Gen 4 PHEV is more fuel-efficient (higher mi/kWh) than the Gen 5 PHEV.

    The EPA rating for Gen 4 PHEV is 25 miles. I get around 38 miles in the city and 30–33 miles on the highway.
     
    #43 Gokhan, Jun 17, 2025 at 2:32 AM
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  4. iRun26.2

    iRun26.2 Active Member

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    Why would they go backwards (Gen 4 PHEV > Gen 5 PHEV)? And by how much?
     
    #44 iRun26.2, Jun 17, 2025 at 3:43 AM
  5. iRun26.2

    iRun26.2 Active Member

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    One thing I don’t understand, and I’m certain you do, is the usable battery charge on the Gen 5 PHEV. If they cut off the EV at 25% (I’ve read this someplace) and only let it charge to 90% to 95% (read this somewhere too), was is the usable EV kWhr available for Gen 5 PHE?. I’d like to know, based on the miles/kWh I see how far I could expect my car to go on EV
     
    #45 iRun26.2, Jun 17, 2025 at 3:52 AM
  6. Gokhan

    Gokhan Senior Member

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    You could look up the EPA mpge numbers. It's because Gen 5 is heavier and slightly less aerodynamic and has larger wheels with no wheel covers on higher trims, which makes it even less aerodynamic. 133 mpge vs. 114 mpge Gen 4 vs. Gen 5 higher trims, respectively. 127 mpge for Gen 5 SE.
     
    #46 Gokhan, Jun 17, 2025 at 5:29 AM
    Last edited: Jun 17, 2025 at 5:55 AM
  7. Gokhan

    Gokhan Senior Member

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    About 1 kWh for HEV reserve and about 1 kWh each for upper and lower buffers. So, you have about 10.6 kWh remaining.
     
    #47 Gokhan, Jun 17, 2025 at 5:33 AM
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  8. iRun26.2

    iRun26.2 Active Member

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    Do you have any information on how the 2012 PHEV worked? Were there any buffers at all? I had one and repeatedly used every little bit of EV that was available to me. I now suspect that was not good for it.
     
    #48 iRun26.2, Jun 17, 2025 at 5:47 AM
  9. Gokhan

    Gokhan Senior Member

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    I am not familiar with Gen 3, but its lithium-ion battery of half size as Gen 4's would have buffers as any lithium-ion battery, perhaps about 0.5 kWh each and a 1-kWh HEV reserve. That leaves about 2.4 kWh for BEV driving, which is consistent with the 11-mile range.
     
    #49 Gokhan, Jun 17, 2025 at 6:05 AM
  10. Trollbait

    Trollbait It's a D&D thing

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    Toyota prioritized looks and performance to help the declining sales. Seems to have worked with the numbers of new to Prius buyers.
     
    #50 Trollbait, Jun 17, 2025 at 10:35 AM
  11. bisco

    bisco cookie crumbler

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    Looking at the gen 3 and 4 form factors, it’s hard to believe gen 4 was more aerodynamic
     
    #51 bisco, Jun 17, 2025 at 12:14 PM
  12. bisco

    bisco cookie crumbler

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    It was very similar with upper and lower buffers, and hev reserve.
    Over 11 years, I did a total of more than 60,000 miles pure ev, and about 25,000 of hev.
    Battery capacity was still 80-85%.
    Why do you think that is not good for it?
    Toyota designed these cars to run ev as much as you choose, with the caveat that we not let the gas go stale
     
    #52 bisco, Jun 17, 2025 at 12:19 PM
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