JD Horsepower?

Discussion in 'Lawn Mowing' started by Wayne Landscaping, May 31, 2004.

  1. Wayne Landscaping

    Wayne Landscaping LawnSite Member
    Posts: 237

    I noticed that John Deere has a rather low amount of hp for their commercial mowers like a 23 hp for the 667 & only a 25 hp for the 757. These machines seem to cut well but can someone tell me why they can have so little hp and such a good cut.

    deerelogo.jpg
     
  2. Pecker

    Pecker LawnSite Bronze Member
    Posts: 1,454

    Well, I can't speak much of the hp because I run a 757 (60"/25) with a mulch kit and haven't found it lacking power for even the toughest of regular mowing situations (2 weeks growth + wet + mulch kit).

    As for the cut, I agree that it leaves a precision cut, very smooth too. Maybe that is due to the 7-Iron deck because I believe the blade tip speed is about the same as other comparable mowers.

    Also, you could choose the JD 797 which has 29 hp with optional 60" deck, which would be much more than the competition.
     
  3. BackAcreFarm

    BackAcreFarm LawnSite Member
    Posts: 52

    I opened a thread "Mower Math" looking at blade speed and noticed the lower HP, too. The Deere's have lower blade tip speed at 16,500 than some others at 18,350.

    Apparently tip speed is not the only factor in a good cut, as many have noted here the Deere's are excellent mowers.

    I assume it takes about the same HP to just move the machines forward at the same speed.

    For example, (this is an example only, I have no idea what it really takes to move a mower) if it takes 10 HP to move the machines:
    A 27 HP machine uses 10 HP to move, leaving 17 HP for the blades, divided by 3 blades leaves 5.7 HP per blade.
    A 25 HP machine uses 10 HP to move, leaving 15 HP for the blades, divided by 3 blades leaves 5 HP per blade.

    Also, it has to take more HP to spin the blades at the higher speeds, I don't know how much.

    I could be all wrong in how I look at this, if somebody knows how it really works please let me know.

    By the way, I own a Deere 777.
     

Share This Page