Power(hp)/weight ratio?

[GeauxLSU]

Not really sure where to post this so hopefully this is the spot.
My question is, is there some type rule of thumb for a workable power/weight ratio? My issue is I'm leaning towards a very small tractor (Like a Kubota B7800 with 30hp and 1,741 lbs) in both stature and weight and can see how you can get similar power in a tractor that weighs significantly more (Like a Kubota L2800 with 29hp and 2,600 lbs). Could they both pull the same size implements for example?
I realize a LOT of this theoretical question deals with soil type/condition and tire type but this is a 'all things being equal' question.
My desire to have a lighter smaller tractor deals with the obvious transporting and manuevarability advantages but I realize there is probably a trade off somehwere.
What is it?
Thanks in advance.

 

[Soundguy]

Lots of variables here. Are you talking ground engagement? or pto powered. A light but powerfull tractor can power a larger pto powered load than a large, but less powerfull tractor.

When yuo are looking at drawbar hp.. you have to look at traction. Hp is useless if yuo can't get it to the ground and keep it there.

If you look at apples to apples comparison, generally a heavier tractor of the same hp will pull a ground engaging implement a bit better than a similar hp yet lighter tractor. Tires will make a difference... 2wd/4wd will make a difference.. ballasting will make a difference.. etc.

For instance.. you can get a lighter 4wd tractor to do similar tasks as larger 2wd tractors. Ever see big ag tractors with dual rears , rear rim weights, and 400-600-800# of weight on a front bracket? That's for traction... so he can get his 70-150 hp to the ground without spinning.. 4wd would help getting that traction down as well.. It's a tire contact area issue. That's why dual rears are better than single rears in some cases. Also helps with flotation.. etc.

Soundguy

 

[GeauxLSU]

Talking about drawbar and everything else being equal.
My specific issue is I plan to get a 4wd tractor and am looking at multiple models, but for example the two models I mentioned are the same in every regard that matter to me except weight and dimensions. I'd like to be able to have a smaller tractor for transport reasons but not at the expense of losing real utility. I plan to use it for primarily rough cutting but will be planting 3-4 acres hopefully twice a year and will need to do some ground turnover initially and then at least disc work going forward.

 

[ronjhall]

I have a B2910. Same tractor as the B7800. But with some premium features. It would have problems with a plow. But I have a 3PH Tiller for my ground working jobs. Even with the tiller I have to be in 4WD to properly till a garden.
These size tractor are designed to cut lawn first. Then by adding weight they can do the other projects that we like to do with our tractors.
To compensate I have purchased heavier weight attachments to get the landscaping jobs done that require a heavier tractor.

 

[roxynoodle]

Just remember you can always add weight when you need it, but you can't really remove it.

 

[bbse]

Talking about drawbar and everything else being equal.
My specific issue is I plan to get a 4wd tractor and am looking at multiple models, but for example the two models I mentioned are the same in every regard that matter to me except weight and dimensions. I'd like to be able to have a smaller tractor for transport reasons but not at the expense of losing real utility. I plan to use it for primarily rough cutting but will be planting 3-4 acres hopefully twice a year and will need to do some ground turnover initially and then at least disc work going forward.

I had a L3010 with R4's. I will say it was fine for brush cutting. When I tried digging or dragging in soft ground the R4's just won't cut it. Also when I went to cut on unlevel ground I found the taller height of the L series raised the Center-of-gravity and it was scarier. I now have a Kioti LK3054. It is about the same size as a B7800, weighs 2974 pounds, has R1 tires and seems much more stable on the hills. I can say I learned the hard way. If I could start over I probably would have started with the B2910 (B7800 was not available in 2000) for the hydro tranny and got R1 tires. I could have added weight for digging. If I was starting from scratch today I would have to throw in Kiotis CK30 HST for a tractor that is B size, has hydro and a lot more weight (3055 LBS).

 

[3RRL]

GeauxLSU
I'll throw in my 2¢ worth.
I don't think rough mowing with a heavier tractor is going to kill you, nor will it for transport reasons (I think). If I were you I'd consider what that extra 859 pounds will do for you. I've read many threads that hover around this topic. What I've noticed is that most users end up adding weight to their tractor for various reasons as discussed above. Rarely do you come across a thread that reads " how do I remove weight from my tractor, I'm getting too much traction?". Not trying to be a smart a$$, but most posts address the opposite problem...

My observation from this (and IMO) is that it's got to be better to have that extra weight, all other things being equal. You read about guys (and gals) hanging extra weight on the front, wheel weights, liquid filling their tires and hanging ballast boxes on the 3 pt all the time. Why do they do this? Ever think about that? I think the tractor would perform better if properly weighted through heavier castings, axles, frame etc. (designed that way) than hanging stuff on it. Consider having to add that stuff everytime you need it and it might become a PTIA. Why not get a jump on it from the get go? It is after all a tractor. If you need something super light weight, like finish mowing so you don't jack up your lawn, consider a machine designed specifically for it. If this not an issue, I'd opt for the heavier tractor. I'm confident that you will end up using your tractor for more things in the future (if not right away while plowing) where "more weight" and (associated benefits) becomes an issue. Like I said, just my 2¢ worth...

 

[Doc_Bob]

In general, heavier tractor is a better tractor and more HP is a better tractor.
Bob

 

[meledward23]

[/quote]
My desire to have a lighter smaller tractor deals with the obvious transporting and manuevarability advantages but I realize there is probably a trade off somehwere.
What is it?
Thanks in advance.[/QUOTE]

Given your desire, I should think the heavier tractor should not be that big of a problem. I suppose that all depends on what you use to tow the machine. Otherwise, weight is the third concern to me for transporting and manuevering.

Turn radius comparisons, wheel base length and width, and machine overall length and width. Also good points of access for using a chain to secure the tractor to a trailer. These are all things I would look at.

My 55 is 83" Outside wheel to wheel on the rear. Means I can only use a deck over tire trailer since the cut off is right at 82" if I recall the numbers correctly. My TC-30 is so small my car hauler is just fine. Very big difference compared to what you are looking at, but the point is for me wieght is not as big a deal as the other factors, width, length, etc....

(DISCLAIMER: I dont worry about weight as much because I have a 1 ton diesel and sufficient trailers)

 

[cisco]

As per prior posts, it depends on what you want to do. If it's just for ground dragging attachments (e.g., box blade, FEL), or just for pto stuff (e.g., brush cutter), fine, the tractor choice is easier, but if it's for both then you'll have to compromise unless you've the rut-making, trailering, garaging and purchase price tolerance for something sufficiently large for any task (which means overly large for most tasks). Yes, a 150 hp 4WD monster with duallies will do most anything, but it'll tear the heck out of you lawn, and you better have a very large trailer and truck.
Me, I've an L3410 GST with 4WD and R-4s, which is pretty well situated in the raw HP/pto HP/weight region of Kubota's medium to small sized stuff. When my box blade is loaded with heavy stuff, my wheels spin; when my 72" Woods cutter is in really heavy and tall stuff, I can only cut 3/4 widths or the diesel will stall; heck, it's a compromise. Sure, I can load tires, add weights and so on (and I've tried), but nothing is perfect for all tasks.
Take your best guess, and live with it (just like a marriage, unless someone out there has found the at all times, and any situation, and over decades of time, absolutely perfect mate).