There’s been confusion about why Ram put big 3.6 liter V6 as a range extender on the 2025 Ramcahrger. Surely that is terribly inefficient?

No, it’s not.

Ram states following specs: 92kWh battery pack, 145 miles of electric range and 690 miles of total range, 27 gallon gas tank.

Electric range of 145 miles with 92 kWh means electricity consumption of 63 kWh/100 miles. Full tank contains 920 kWh of energy and gives 545 miles of range. That is consumption of 168 kWh/100 miles. The electric energy needed for 545 miles is 343 kWh, so the efficiency of the range extender is 37%. The generator and electronics have some energy loss so the efficiency of the V6 engine is closer to 40%. That’s crazy efficient for a gas engine.

Why is it so high? Why not use smaller engine?

Engine efficiency is highest at relatively slow speed and nearly full load. That big V6 can produce the required power at low RPM but needs to work hard. That’s very efficient. Smaller engine would need to run very fast which decreases efficiency.

In summary the V6 is very efficient at this particular application which suits it very well.

  • feurie@alien.topB
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    1 year ago

    The F150 hybrid gets 24 MPG and has been out for a while.

    This system gets 20MPG on gas.

    • ham-nuts@alien.topB
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      1 year ago

      I agree 20MPG on gas isn’t great, but that’s not really the point on a range-extended EV, especially one with such a high EV-only range. The average driver only drives 37 miles per day, and I’m willing to bet that number isn’t much higher for light-duty pickup owners.

      I own a Volt and even with only about 60 miles of EV range I only use gas maybe 3-4 times per year. And so the fuel efficiency that I gets when I do use gas is a pretty minor concern.

      From talking with truck owners around me, the biggest roadblock to getting them to consider an EV truck is that they want ability to tow/haul something longer distances if needed (and to be fair, the range on EV trucks goes down significantly when towing). But at the same time most will admit that they only used their hitch maybe twice in the past year.