Do you know how much your tractor should weigh?

[bdog]

I was doing some reading last night and came across a very intersting article on tractor weight, traction, efficency, etc.

According to the article 2wd tractors pulling ground engaging implements should weigh between 110 -160 lbs per pto HP. 4wd tractors should weigh between 95-140 lbs per pto HP. these numbers are based on extensive testing and if you go lighter you will have excessive wheel slip and heavier you will have excessive rolling resistance.

The lower weight numbers in the range are for travel speeds of 6mph and the higher numbers in the range are for 4 mph.


According to this most of us need to add some weight or at least I do. I guess it does not really matter unless you are plowing a lot, but according to the article you are wasting as much as 20% of your HP by not having your tractor the proper weight.

 

[Bob_Skurka]

I am guessing that this is a farming related article you were referring to? For AG purposes it makes perfect sense given the amount of ground engaging work that can be done with those machines.

Without bothering to check on my machines, I know I use a very light unit and a mid-weight unit. As very very little of what I do is ground engaging, I would favor the higher HP to weight ratio over the higher weight to HP ratio. I don't doubt the accuracy of the article, but I am more concerned with blowing snow, cutting grass, tilling the garden and running a PHD than I am with attempting to pull a two bottom plow.

Regarding the whole issue of traction = weight . . . What I know is that a 30hp tractor will pull a 5' box blade, and maybe a really heavy 30hp tractor might pull a 6' box blade, but most are limited to 5' box blades under most circumstances. I can pull a 5' blade with the ultra-light B2910 and I doubt if a heavier tractor like a TC30 could pull a 6' without a major struggle.

I believe there are some "practical" applications for us CUT users where higher HP to weight ratios make more sense than high weight to HP ratios do. But I also believe it really depends on the TASKS you ask a tractor to do. If you do a lot of ground engaging work, then a heavier tractor will be a better choice. But if plowing, logging and box blading is a small % of your work, and tilling, mowing, snow blowing & PH digging is a large % of your work, then I don't think it makes sense to buy heavy machines. For FEL work, I think a balanced & ballasted tractor is better than either a light or a heavy tractor.

 

[MessickFarmEqu]

I question how meaningful these things are on a CUT. I recently bought a load cell and in a few weeks I am going to do some testing to see how much weight really does play into things.

 

[Bob_Skurka]

Neil, that would be very interesting to see. As my experience is with sub 35-hp tractors, I've often questioned the purpose of extra weight for most rural homeowners. It would be nice to see if a B3030 and a TC29 use the same implements given the weight difference between the two. I suspect that for the most part, the TC will pull a 5' box blade easier than a B3030, but I doubt it would pull it well enough that you'd want to jump up to a 6' box blade. That said, from the "practical" application standpoint, they both might be limited to the same implements, although one probably should pull the implement a bit easier. Then again, with a finish mower, tiller or snowblower, there should be no real reason why heavier would be better that I can think of.

Now when it comes to folks who do things like pull logs for a living, tote around large round bales of hay, etc, then I totally believe in a heavy tractor.

Don't get me wrong, I do agree that weight = traction, I just tend to think that if you do things around the home like landscape and property maintainence, mowing, tilling, blowing, etc then it really doesn't matter if the tractor is heavy, as long as it is ballasted properly.

 

[frank_f15]

For the most part i think the HP to weight on my tractor is about right. There are times i wish i had more weight (traction) but that is usually when i am trying to do something at the upper end of my tractors limits.

 

[txhawg]

</font><font color="blue" class="small">( According to this most of us need to add some weight or at least I do. I guess it does not really matter unless you are plowing a lot, but according to the article you are wasting as much as 20% of your HP by not having your tractor the proper weight. )</font>

Shouldn't the manufacturers know this? I know for a fact that they spend millions of dollars a year on R &D. I would hope that they have discovered this fac long before the article was printed, and corrected any flaws in the wieght/horsepower ratio long ago.

 

[bdog]

</font><font color="blue" class="small">( Shouldn't the manufacturers know this? I know for a fact that they spend millions of dollars a year on R &D. I would hope that they have discovered this fac long before the article was printed, and corrected any flaws in the wieght/horsepower ratio long ago.)</font>


I think they do know it. I mean it is simple physics. More weight equals more traction. As stated above most people who are shredding, digging post holes, rototilling, landcape rake, etc are not doing anything where they need all the traction. Lighter tractors are cheaper to build. Lighter tractors are cheaper to ship, easier to haul, etc. I am sure there are more compact owners want their tractors light so that they can haul them with their small trailers and 1/2 ton trucks than there are who want a heavy tractor that gets the most traction possible.

The manufactures make wheel weights, front weights etc. They know they do increase traction and some people need them.

I guess what I am saying is that not everyone needs the extra weight, but if you want to be able to get the most pulling power possible out of your tractor then follow these guidelines.

By the way if any of you want to read this article here is a link. http://www.oznet.ksu.edu/library/ageng2/mf588.pdf

 

[KiotiJohn]

At approx. 124# per PTO HP, mine is right in there. I could even use a little more weight when pulling my disk bedder as it tends to pull me off a straight line. John

 

[willfick]

My two older tractors are weigh over. (Nice pun, eh?)
The '46 Farmall H is about 200 lbs/ hp. The Ford TLB is 263. I guess the TLB is more like construction equipment, so data on plowing wouldn't really be relevant. As for the H, I've heard it said that the horses were bigger back then. /forums/images/graemlins/wink.gif
Wm

 

[Slamfire]

I solved my traction and roll over issues with one modification. /forums/images/graemlins/laugh.gif