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All you need to know about TOWING!!

Discussion in 'Gen 3 Prius Technical Discussion' started by Bryan L, Apr 27, 2021.

  1. Bryan L

    Bryan L New Member

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    I have a 2013 Prius 4 that I successfully towed 1000 pounds about 2500 miles! Here is what happened:

    after all my research and after talking to Toyota’s mechanics here is what they said, “YOU CAN TOW, it will put strain on the rear wheel bearings and the transmission. But don’t tow more than 1000 pounds.”

    so I built a Harbor Freight trailer for my Honda Africa Twin motorcycle. The bike is 510 pounds. The trailer weighs 250 pounds. Plus I put a ramp and spare tire on there. Then I had my Prius packed with luggage and a cooler and my GF riding shotgun.

    I towed my bike from San Diego to Gig Harbor, WA. It was 1200 miles each way. The two hill climbs I was worried about were the grapevine and siskiyou pass. They are steep climbs.

    For the hill climbs I’m in B mode going 40 mph. I have a OBDII reader to monitor engine temp. The engine is wound up but not too bad. Cruising 65mpg on flat surface the car handles well.

    Overall the car did just fine. It was weighed down in the back and here’s probably what you’re all wondering: what was your MPG?

    MPG: 33 mpg round trip.


    If you’re thinking of towing. Go for it. Just keep it under 1000 pounds and shift in and out of B mode and monitor the engine temp on hill climbs in the slow lane with the semis. Hope this helps someone considering towing.
     

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  2. PriusCamper

    PriusCamper Senior Member

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    Some towing pics I've gathered over the years:

    Towing3.png Towing2.png Towing1.jpg 189358_IMG_20200601_102117_171.jpg 157924125_10218509105990197_4134426705016510037_o.jpg
     
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  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    B mode going up the hill? Not sure that’s needed, helpful. The logic for doing that?
     
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  4. Grit

    Grit Senior Member

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    since you didn’t provide a disclaimer, you will be held financially liable for all damages that occurs on our Prius when when towing?
     
  5. ChapmanF

    ChapmanF Senior Member

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    What temperatures were reached? Were you also monitoring MG1, MG2, and inverter temps? What did they reach?
     
  6. Ed Beaty

    Ed Beaty Active Member

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    "The engine is wound up but not too bad."

    What does that even MEAN?
     
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  7. fuzzy1

    fuzzy1 Senior Member

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    B mode is irrelevant on the climbing side. Here, it is no different than D.

    B mode is important on the descent.

    I'm seeing both passes as having 6% grades descending northbound, or climbing southbound. While steep, that is still short of the 7% grades on numerous other roads.
     
  8. bisco

    bisco cookie crumbler

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    how can we determine if ny excess tranny wear has occurred?
     
  9. Bryan L

    Bryan L New Member

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    it drops it down a gear. I had it in D and B going up hills and B mode was much easier on the transmission temps.
     
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  10. Bryan L

    Bryan L New Member

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    The RPMs are high! The engine is not liking pulling 1000 pounds up a hill.
     
  11. Bryan L

    Bryan L New Member

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    Take a part the transmission and look. But I haven’t had any shifting issues since I did that long tow. 150k miles on my car now
     
  12. Bryan L

    Bryan L New Member

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    Go tow a heavy trailer up some long hills and you tell me what felt easier on your car. For me it was B mode. I know it’s for engine braking but they achieve that by dropping it down a gear.
     
  13. fuzzy1

    fuzzy1 Senior Member

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    But a Prius doesn't have any gears to drop down to.
     
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  14. ASRDogman

    ASRDogman Senior Member

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    An accident BEGGING to happen!
     
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  15. rjparker

    rjparker Tu Humilde Sirviente

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    The real issue with towing are the brakes that are not designed for it. Yes, the B mode on descents is exactly what the mode was made for, eg to provide engine braking when the battery capacity is maxed out. A better towing Prius is the third gen v with a lower final drive ratio, bigger standard tires and brakes.
     
  16. ChapmanF

    ChapmanF Senior Member

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    I'm still hoping to hear more about that gear it drops down.
     
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  17. Grit

    Grit Senior Member

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    which gear does it drop from?
     
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  18. PriusCamper

    PriusCamper Senior Member

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    Exactly!
     
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  19. rjparker

    rjparker Tu Humilde Sirviente

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    Technically it does have gears in the transaxle that change ratios according to load. So you can suggest it "drops" down to a lower (higher numerically) gear ratio. Maybe "changes" to another "lower" gear ratio is closer to proper language since no transmission literally "drops down" in space to achieve something.

    Any automatic transmission that can "change gears" also has a planetary gear set. You have to "drop" down to a true manual transmission before the term becomes significantly mechanically correct.
     
  20. ChapmanF

    ChapmanF Senior Member

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    At least that would bring us back to the original question of whether B mode on an uphill in fact does any such thing.
     
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