Tractor Sizing Rules Of Thumb For Tractor Size, etc?

[adamjthompson86]

Thanks all for your help in this thread in helping me understand why utility tractors are more expensive than riding lawn mowers and why I can't compare their horsepower numbers. I have some follow-up questions, now:

Are there rules of thumb for how much horsepower you need for certain tasks or attachments? (i.e. X HP for a 60" rotary cutter, X for loading dirt, X for towing a wagon.trailer with x pounds on it, X for digging up rocks with a backhoe, etc) (I realize that power is not the only factor - using a backhoe, for example, requires a heavy enough tractor to keep from being dragged around).

Without a point of reference, HP ratings aren't very helpful. Are their accurate ways to know if a tractor has enough power to do certain jobs, or is that something you more have to learn and guess based on your experience with different tractors?

Are horsepower ratings a reasonably accurate way to measure utility tractors and compare them to each other?

Thanks!

[eatenabean]

For me, I picked the HP for what I wanted to do. Pull a Six foot bush hog without a problem. So that put me in the 40HP range. Now I can cut my 6 acre field in 2 hours instead of about 8 hours with a Craftman 26 hp 54in cut lawnmower.

[timswi]

Honestly, I believe that you must pair the tractor to intended use. If you have a 1 acre lot, then a Grand L Kubota probably isn't a good idea.

Most of the compact and sub-compacts are very well designed in terms of horsepower and weight to impliments available for them. I've heard that rear mount mowers should be 5 hp per foot of width.

Tillers etc are going to be limited by 3pt lift capacity and HP. Although a sub-compact tiller will be weight and power matched given it's size, unless you try to push it.

Loaders and BH's have specs like break out force, digging depth, and overall weight and capacity..Those are good for comparison.

I wouldn't get too attached to horsepower. Worry more about what you intend to use it for. Do you need 4x4? What kind of trans is going to work best for your work..Etc.

Don't buy too big, and don't buy too small...

Let us know what you're going to be doing....I'm sure you'll get more opinions than you can digest.

[_RaT_]

"Do you need 4x4?"

Of course you need 4WD, even if you don't you do!

[dex3361]

I would say weight and HP and whether a tractor is 2 or 4wd sometimes referred to as MFWD (Mechanical Front Wheel Drive).

The number you will hear quoted a lot is 5(PTO)HP per foot of mower and that is a little flexible.

When it comes to a Box Blade (BB) you should get it by the width of the tractor wide enough to cover the tire tracks.

Scraper Blade is usually get it about 1 foot wider than the tire width so you can angle the blade and still cover the tire track.

I am sure others can throw in more.

[timswi]

"Do you need 4x4?"

Of course you need 4WD, even if you don't you do!

Can't argue with that

[adamjthompson86]

For me, I picked the HP for what I wanted to do. Pull a Six foot bush hog without a problem. So that put me in the 40HP range.

How did you know that you need 40HP to pull a 6' rotary cutter? Is there a chart or formula or something?

[adamjthompson86]

The number you will hear quoted a lot is 5hp per foot of mower and that is a little flexible.

That sounds helpful. I'm guessing that's 5 PTO HP, not total HP?

Are there formulas for other tasks like lifting weight, towing weight, etc?

[eatenabean]

I have friends who have tractors, and I asked the dealers what they would recommend for a 6 foot bush hog. Everyone I talked to come up with around 40HP. Oh and from reading on here. No charts, just other peoples experience.

[adamjthompson86]

No charts, just other peoples experience.

I'm gathering that buying a tractor is a little less scientific than buying a vehicle. Instead of comparing MPGs, 0-60, and crash ratings, it's more like...

"Hey Bubba! Y'reckon this here tractor'll till up that thar plot o' land?"