What rpm at 65mph ???

Discussion in 'Questions From New Drivers' started by The Wiz, Jun 4, 2020.

  1. Concorde

    Concorde Road Train Member

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  2. longhaultransport

    longhaultransport Light Load Member

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    Is that in top gear?
     
  3. The Wiz

    The Wiz Bobtail Member

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    Thank you Concorde gor the extra effort. That is a great rpm.
    Good looking tractor by the way !!!
     
  4. The Wiz

    The Wiz Bobtail Member

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    Concorde, these numbers don't add up to the formula.
    Either you have low pro tires or 3.58 roughly rear ratio ?
    Any thoughts ?
    With the configuration that you have you should be at 1275rpm at 65 mph ??
    Am I doing something wrong with my calculations ??
     
  5. bryan21384

    bryan21384 Road Train Member

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    Our trucks our governed at 65, they turned the RPMs down to where it runs 65 at 11-1200 RPMs max. It didn't effect the power in my mind, but Volvos actually pull very well even when governed. I am getting 7.7 miles per gallon as of today, my load is 39000 roughly in a slightly heavier reefer trailer. If you run 65 mph at 1400 RPMs, the sweet spot on that particular truck has to be somewhere around 60-63 mph if you're trying to get good fuel mileage. More RPMs means more power, more fuel consumption, especially under heavy loads.
     
  6. The Wiz

    The Wiz Bobtail Member

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    Yes, I agree...Volvos are a different animal and pull well on hills.
     
  7. Brettj3876

    Brettj3876 Road Train Member

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    My opinion is the 3.70s are a great all around gear esp if running a lot of hill country.

    Looking at that chart if you stay 63-65 you're looking at good overall mpg and better start-ability than the taller rears
     
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  8. Concorde

    Concorde Road Train Member

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    Yes, was in 18th on flat terrain... with 41k in the reefer.
     
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  9. Concorde

    Concorde Road Train Member

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    I have Low Pro tires..just assumed most trucks have them now.
     
  10. The Wiz

    The Wiz Bobtail Member

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    Ok, thanks for the info. Wasn't sure if the calculations were correct.