Would it be better to run in HV mode before Charge Mode

Discussion in 'Prime Main Forum (2017-Current)' started by schja01, Aug 19, 2020.

  1. schja01

    schja01 One of very few in Chicagoland

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    I'm at the point where I need to burn off some soon to be stale fuel. I figured Charge mode would be an alternative than just tooling around in HV mode as the engine will run until LOC reaches 70% 80%? The engine definitely sounds louder in Charge Mode and I suspect because of the additional load. Would it be easier on the engine if I ran in HV mode long enough for it to warm up and then switch to Charge Mode? Or am I overthinking it? Looking at the MPG I get about 20+ in Charge Mode at 30-35mph so I suspect it burning a decent amount of fuel which is what I want to do plus I do get some energy captured to the battery which is better than just putting miles on the car to burn the same amount of fuel. Thoughts?
     
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  2. Trollbait

    Trollbait It's a D&D thing

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    My first thought is how do you know the gas is going to be stale soon? Did you get the warning to add fresh gas?
    Car gas tanks are better sealed than the cans for power equipment to keep the fuel 'fresh' longer, and PHEV tanks usually take a couple more steps for that. The car knows when you last added enough gas, the engineers know how long the fuel can safely be left in the tank, and the monitoring system should warn you long before there is a risk from the gas going stale.

    If you got the warning, adding 3+ gallons will be enough to freshen the tank gas back up.

    Tank still full. HV mode will make more efficient use of the gas. If you need gasoline for something else, and have the means for siphoning, that would be better than burning it in charge mode in terms of resource use.
     
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  3. jerrymildred

    jerrymildred Senior Member

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    +1 to @Trollbait's response. It takes a long time for the Prime's gas to go stale. I just filled up after 5-1/2 months. It was doing fine.

    But if you do think you should burn off some gas, it might be slightly cheaper to do it in HV mode. Or it might be a wash. In HV mode at 60 mph or slower, the car pretty much alternates between EV and Charge modes all by itself. On a 50 mph road I often drive, it'll go about 1-/12 to 2 miles in HV and then the same in EV and the back to HV. This should keep the engine warmer than it would if you ran in Charge mode since it doesn't stay off for as long.
     
  4. schja01

    schja01 One of very few in Chicagoland

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    I have gas that is 75% a year old. No warning indicator yet. Looking for a way to use up the gas at low speed (eg. Less than 40 mph) and charge mode seemed the best way to burn it off per hour at those speeds.
     
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  5. Trollbait

    Trollbait It's a D&D thing

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    You probably won't see any message from the car for another 3 months then. If the tank gauge isn't already at 3/4ths full, I'd start using HV mode more often, and only go with charge mode when closer to the one year mark.

    Or don't worry about. With other PHEVs, the car would soon starting using the engine more often after the warning message and no fresh gas was added. Even not allowing EV use. I don't think anyone here as actually had a Prime get to that point yet, so its actual behavior is unknown.
     
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  6. schja01

    schja01 One of very few in Chicagoland

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    Another factor for me a nonessential (retired) individual is I do much less driving with the COVID situation as it is. I did add a few ounces of STABIL to the tank as a protective measure.
     
  7. Tideland Prius

    Tideland Prius Moderator of the North
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    I was gonna say, just drive it in HV mode like a regular Prius but I guess if it's short enough distances, it may still take a while. But then again, CHG mode only charges to 80% and you still have to drive that distance in EV mode.

    I guess it wouldn't hurt to turn on HV mode, let the engine do its warm-up cycle before putting it into CHG mode.
     
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  8. Tips

    Tips Member

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    I don't believe we should ever fill our tanks unless we know we will burn it , such as on a road tip! Otherwise just keep a gal or so in the tank!

    Posted via the PriusChat mobile app.
     
  9. Salamander_King

    Salamander_King Senior Member

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    How many miles of driving say per week are you currently doing? I am driving around 50miles/week since mid March, but still needing to fill the tank once every 4 months. This is doing mostly EV/HV mixed drive. I only charge the traction battery to 30-40% since the car sit idle for most of the time.

    I guess what I am suggesting is what you always recommending... That is "Just drive it." LOL ;)
     
  10. schja01

    schja01 One of very few in Chicagoland

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    Currently 5 to 8 miles per week max. The other car of ours about the same but it gets 15 mpg.
     
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  11. Salamander_King

    Salamander_King Senior Member

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    OK, you are really not driving much. It will take years before you can burn 3/4 tank of gas. Even if you use CHG mode for that 5 miles, I don't think you are going to make a dent with that little of driving you are doing. Besides, what would you do when you have 80% SOC in traction battery? That would be 4 weeks worth of your driving, you will not be using any gasoline.

    My recommendation is "Get out of the house more often, and just Drive It". You don't have much to worry if you are not stopping at shopping malls and bars. Take a nice drive on the LSD and back to your safe home. You are all set. Here are other fine drives around Chicago.

    9 Most Scenic Drives in Chicago
     
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  12. schja01

    schja01 One of very few in Chicagoland

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    I figure at worst case I have 600 HV miles in the tank. It would take 11 miles per week in HV mode to burn off most of it in one year. So if I alternate between EV and Charge Mode do I burn the same amount of fuel as just running straight HV mode? Math wizzes here is your chance to impress me. :)
     
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  13. eatriceyo

    eatriceyo Junior Member

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    put your car in power mode and have some fun
     
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  14. schja01

    schja01 One of very few in Chicagoland

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    Alas, that would kill my State Farm “Drive Safe and Save” 30% discount. Fast Acceleration is one of the metrics that causes you to loose points.
     
  15. jerrymildred

    jerrymildred Senior Member

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    My recommendation, too, unless you're under house arrest. I average about 200 miles a week and that's just routine stuff without pleasure trips. It's really unhealthy to stay cooped up in the house all the time. You need sunshine, variety, fresh air, etc. for physical AND mental health.
     
  16. Trollbait

    Trollbait It's a D&D thing

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    Are you still in the trial period, or does State Farm monitor you always?
     
  17. schja01

    schja01 One of very few in Chicagoland

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    Always. Required to run the smartphone app whenever driving and odometer confirmations twice a year.
     
  18. m8547

    m8547 Senior Member

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    I wouldn't tolerate that invasion of privacy (even if it's a voluntary program).

    If you're really only driving less than 600 miles a year, insurance should be inexpensive from any company.

    And if you're really worried about saving money or helping the environment, you might be better served by a vehicle that isn't an almost brand new car. The Prius is meant to be driven, and it will do the most good for the environment if it's in the hands of someone who drives more than average, as opposed to them driving a less efficient vehicle. The safety features of new cars are great, but with low miles driven your chances of a dangerous crash are very low.

    Hopefully this comment doesn't come across as too negative. It's just the thought process I would personally follow.
     
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  19. MTN

    MTN Member

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    Take a nice long drive, have a picnic at your destination, go for a walk, etc, then come home. Find somewhere to avoid people and try to avoid public restaurants/restrooms too.
    My 2 cents.

    Oh, and I feel like if you floor a Prius, it won't be accelerating fast enough that your insurance company would care!
     
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  20. schja01

    schja01 One of very few in Chicagoland

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    Definitely wrong especially in EV mode. Firsthand experience on that one.

    In our age group the bladder becomes a distance limiting factor. No public restrooms for us.

    Even with our low mileage we save about $300 total per 6 mos for both cars combined. Definitely worth it to me.

    Here are the scoring factors considered in the app:
     

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    #20 schja01, Aug 20, 2020
    Last edited: Aug 20, 2020
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