Tractor weight vs. fuel consumption while mowing?

[JIGBUILDER]

I mow my 40 acres several times a year. Midland bermuda/fescue/red clover/blackbery vines and just about every weed that is native in my area. My FEL weighs 1500-1800 lbs so the tractor can definatly tell the difference when I'm mowing up a hill with the 50 hp tractor and a 7' mower. My loader stays off all mowing/haying season. If its needed it goes on easy. My tractor/FEL/mower weighs 7200-7300 lbs.

I remove the loader in mowing season as its just more weight beat'n on the tractor and carrying around more unnecessary weight plus the big thing is mowing in close quarters. With my Rhino/tractor/loader its close to 24' long.

Lots of variables as we all don't use the same size equipment or mow the same type materials and on different terrain/soil types/etc. The tractor operator can tell what his equipment is doing. A engineer woud be clueless.

 

[JDgreen227]

Yanmar lists a newer version of your engine with the same displacement at approximately 0.057 gal per hp/hr @ 2600 rpm.

For an example:

If your engine is hypothetically perfoming 20 hp of work mowing with the loader on at 2600 rpm, it is consuming roughly 1.14 gal/hr. If dropping the loader reduces the amount of hp the engine needs to produce to maintain desired pto speed to 19 hp, your consupmtion drops to roughly 1.083 gal/hr.

At $4.25/gal, the savings equals about 25 cents per hour for each one hp reduction.

The only way to know what the difference actually is, and to figure out how much work the tractor is actually doing is to "do a little experimenting".

Thanks for that information...if my Yanmar is only burning about a gallon per hour while mowing (I run it about 2400 rpm) I am happy to learn that. My older mowing tractor, a Deere 318 gas engined Onan, burned a gallon of fuel an hour spinning a 50 inch deck, and it weighed just over a half ton with the deck installed. According to your numbers, I am running a tractor/mower combination that weighs 3X as much, with a 20% wider cut, for basically the same fuel cost per hour as my older one required. And it cuts grass a lot faster in the process, which further reduces fuel expense.

BTW, I can easily tell the engine is not working as hard to spin the mower when the FEL is removed. The weight reduction makes a difference, probably because the Deere 4210 is sometimes considered underpowered.

 

[TripleR]

My way of thinking, too, is that less weight would mean less power (and therefore less fuel) needed to keep operating at a steady speed. Back when I was working, we had a selection of cargo vans ranging from a half ton model with a 350 V8 to a one ton model with an inline 292 cubic inch six, with one of the heaviest one ton vans using a 350 V8. In both city and highway driving, the lighter half ton/V8 models got several more mpg than the heavier one ton models fitted with a six cylinder, and the one ton models with the 350 V8 got 5 mpg less overall. Overall gearing had them all running about the same rpm at any given freeway speed. I figured the increased weight HAD to be the cause of the decreasing fuel mileage.

Agreed, I can tell the difference in performance on my pickup hauling or towing additional weight. I don't see how anyone can say that in general significant additional weight does not affect performance and fuel usage. The only question being by how much.

Hmmmmmmm....

Anyway, dropping the FEL would likely save some fuel...but maybe a gallon or two over the course of a mowing season? That wouldn't be worth the trouble of dropping the FEL. Not that there aren't good reasons for dropping the loader off (I did for my old 790 and I will for my 4400 (as soon as I figure out a place to park the 430 loader)...but that's for maneuverability and stability on my slopes).

TripleR has a really good point about the accuracy of measuring fuel consumption. Typical fuel gauges (automotive or tractor) are good for ballpark estimates of consumption, but that's about it.

Agree completely, while we put several hundred hours a year on different tractors mowing, we remove the FEL primarily for maneuverability, "stability" etc., fuel saving is just a by product and up until now really never thought much about it.

The amount of fuel your burning idling the tractor taking the FEL on and off more than likely negates any weight savings. Plus the added wear and tear on the FEL mounts, and your added time. IMO its like spending dollars to save dimes, just not worth it.

It takes me two to three minutes to remove my FEL with the engine running less than a minute.

I suspect, though I can't prove it that my pins etc. get more wear bouncing around on my tractor for several hours/days than it will sitting in the barn for an equal amount of time.

Just my opinion and won't apply to everyone.

A engineer would be clueless.

:laughing:

Seriously though, we run similar equipment in the hills and there really are too many variables for any kind universal answer. I just do what seems to work for me.

 

[piller]

Usually in these type of threads I'll see Art post about the importance of a tractor that is properly ballasted for the job which provides the best fuel economy.

For me when mowing I prefer to remove the bucket and loader because:
1) they are big and reduce maneuverability
2) they are heavy which causes more stress on the tractor front end (I don't need the added weight for traction when mowing)
3) the extra weight is causing more ground compaction.
4) better fuel economy
5) the FEL is not needed for the mowing job
6) better visibility
7) I think my tractor is more stable on slopes without the FEL

I think the tractor will get better fuel economy while mowing without the weight of the FEL in all situations except if the tractor is too light for the situation; the mower is too big and heavy and is pushing the tractor around, the tractor does not have adequate traction for the job conditions, etc.

 

[xtn]

Unless you're referring to the technical definition of accleration and not how people commonly define acceleration, I assure you even at a steady speed, if your yard has any slope to it, you will certainly burn more fuel if you are towing extra weight up a hill vs not having that extra weight.

I agree and did address elevation changes in my original post.

xtn

 

[xtn]

To determine if there is different energy requirements by weight, push a tractor that weighs 100 lbs. 5 miles on level ground. Now push a tractor that weighs 5,000 lbs. over that same trail of level ground. I think I know which one would make my tongue hang out but I'm no enjineer.

If you truly had flat, level ground the whole way... If you had the same rolling friction (might require a lot higher air pressure in the tires of the heavier unit, and makes assumptions about axle bearing loads, etc.)... Then it shouldn't make any difference.

It would take more energy to get the heavier unit rolling. But that unit would coast further at the end of the run giving back the energy lost in the beginning. Maintaining a constant speed only requires matching the energy lost to friction. That's regardless of weight/mass.

xtn

 

[SandburRanch]

If you truly had flat, level ground the whole way... If you had the same rolling friction (might require a lot higher air pressure in the tires of the heavier unit, and makes assumptions about axle bearing loads, etc.)... Then it shouldn't make any difference.

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For all practical purposes let's look at it just as we use them and not with an eye for engineering friction formulas and 6 cylinder words.

 

[xtn]

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For all practical purposes let's look at it just as we use them and not with an eye for engineering friction formulas and 6 cylinder words.

Sorry. I am prone to that stuff.

In the real world a big tractor can probably mow an acre using less fuel than a push mower thanks to greater efficiencies despite the fact that it might be a hundred times more massive.

Is that better?

xtn

 

[kday64]

I was thinking about disassembling my neighbors neon and mounting its spoiler on my ROPS with zipties. I hear those improve fuel millage.

 

[Snaker]

I was thinking about disassembling my neighbors neon and mounting its spoiler on my ROPS with zipties. I hear those improve fuel millage.

Your question is very difficult to answer accurately due to widely varing conditions. I believe that fuel usage in tractor design has been oriented more towards performance rather than the rate of fuel burned. If one tractor burned more fuel but pulled a greater load, it could be considered more efficient than another. If that tractor wasn't pulling the maximum load, then it could be less efficient. I have a Nebraska Tractor Test book that covered that. They went to great lengths to test and rate the fuel used to work done ratio under controlled conditions and still had critics of their results (mostly from manufacturers that didn't show well).

Older tractor manuals would often have instruction on proper pulling setup to include a wheel slippage percent. They intended for the tractor to be spinning slightly for best operation. The key was to match the power to the load.

I had a tractor that was having trouble pulling a 5/14 plow in wet clay one year. I switched to a 3/16 (70" down to 48") and it seemed like I was using less gas per acre although I never was sure.

PTO operation has issues of its own because of the rpm requirement. A tractor running at PTO speed will burn more fuel although the load will have some effect. Old gas carbs often had a thumbscrew for a "pulley load" adjustment. You could richen or lean for the amount of load applied at the high rpm.

As far as the loader goes, if your willing to remove it, it has to have some benefit for the reasons others here have stated. Can't say if you will notice it in the wallet.

Sorry. I didn't mean to do a quote.

 

[Snaker]

If you truly had flat, level ground the whole way... If you had the same rolling friction (might require a lot higher air pressure in the tires of the heavier unit, and makes assumptions about axle bearing loads, etc.)... Then it shouldn't make any difference.

It would take more energy to get the heavier unit rolling. But that unit would coast further at the end of the run giving back the energy lost in the beginning. Maintaining a constant speed only requires matching the energy lost to friction. That's regardless of weight/mass.

xtn

I don't buy your science XTN. In space you might get a free ride on coasting but not on planet Earth. I bet a trucker would have a good idea on the difference in milage from pulling an empty trailer vs one thats full.

 

[xtn]

I don't buy your science XTN. In space you might get a free ride on coasting but not on planet Earth. I bet a trucker would have a good idea on the difference in milage from pulling an empty trailer vs one thats full.

An enclosed trailer that is empty versus an enclosed trailer that is full; on flat road and maintaining a constant speed it will take the same amount of fuel.

If a heavier load won't coast farther, why are bigger breaks required to slow it down?

xtn

 

[gordyy]

[QUOTE=Snaker;2372677could richen or lean for the amount of load applied at the high rpm.

As far as the loader goes, if your willing to remove it, it has to have some benefit for the reasons others here have stated. Can't say if you will notice it in the wallet.

thats really the only place I notice it the butt cheek the wallet is under the extra bounce about drives those credit card into it
I swear you could etch the top credit card on my *** cheek after an hour of mowing witht the front end loader on
mines off just for the bounce

 

[Nightrain1]

Lol @ anyone who thinks a full box trailer will pull as easy as an empty one.

 

[mx5guy]

My tractor seems to get better gallonage (if there is such a word) at around 1500 RPM than 2000 RPM, fuel consumption has to with work being performed, and cost is relative to the ammount of work being done.

 

[art]

Usually in these type of threads I'll see Art post about the importance of a tractor that is properly ballasted for the job which provides the best fuel economy.

For me when mowing I prefer to remove the bucket and loader because:
1) they are big and reduce maneuverability
2) they are heavy which causes more stress on the tractor front end (I don't need the added weight for traction when mowing)
3) the extra weight is causing more ground compaction.
4) better fuel economy
5) the FEL is not needed for the mowing job
6) better visibility
7) I think my tractor is more stable on slopes without the FEL

I think the tractor will get better fuel economy while mowing without the weight of the FEL in all situations except if the tractor is too light for the situation; the mower is too big and heavy and is pushing the tractor around, the tractor does not have adequate traction for the job conditions, etc.

I have been away from the computer for a couple of days and I see that I've been covered!! It takes more power to move more weight which in turn burns more fuel!

For some of the comments here I think a combination of front and rear spoilers that could be used as solar panels would help the most.

 

[houstonscott]

I think there are a few things you could do to improve fuel economy while mowing. First is to select a tractor that is not to big for what your doing. All the newer high pressure common rail diesels will out perform diesel with a governor on fuel economy. Make sure you mow at speed/gear that puts the engine near max torque, as long as the mower is working fine if that is less then 540rpm who cares. Pull a mower that maximizes your tractor too, less passes means less fuel. Less weight will help, no one can deny that but how much will it change things. I think speed and gearing will effect your economy more than that FEL weight. Adding a few cetanes with an additive will improve economy too.

 

[jenkinsph]

With diesel currently selling for $4.25 per gallon locally, I have begun removing the 420 loader fitted to my 4210 when not using the loader. Most of my operating hours are mowing time, and while I always removed the 61 inch HD bucket before mowing, I thought pulling the entire FEL was too much bother...UNTIL diesel fuel got so expensive.

We are told that removing excess weight from our car trunks will increase miles per gallon, but has there ever been a study as regards tractor weight and fuel consumption? My MFWD Deere weighs about 3100 pounds when fitted with the 60-inch 7-Iron deck. Removing the loader probably means 450-550 fewer pounds for the Yanmar to move around. Is there any way to calculate the reduction in fuel consumption by removing the extra weight of the loader? Thanks.

This is the original post

I know I can cut my back yard with the X749 using a little more than a gallon of fuel, approximately 1.25 acres. Savings? Were really talking nickels and dimes here.:laughing:

 

[Farmwithjunk]

OK....Thought about skipping this one, but decided to throw in my $.02 worth...


I own and operate a commercial mowing business. We mow (among other things) highway right-of-ways. As part of the fleet, I have 3 IDENTICAL John Deere 6430's. They all 3 pull 15' Bush Hog batwing mowers. One 6430 is used occasionally at my farm or my sons farm. That tractor has cast weights, and a loader (only the subframe stays on while mowing). The other 2 DON'T..... Long story short, that tractor packs 1880lbs more than the other 2 6430's while doing the EXACT SAME JOB.

They all three use (within drops) the same amount of fuel in an 8 hour day. So.....from the hard evidence I have, and "theories" be damned, there is no measurable difference in fuel economy while mowing with any REASONABLE amount of weight added/subtracted from a tractor.

 

[TripleR]

I doubt this will ever be resolved to everyone's satisfaction. My father in law traded trucks every two years and they were all configured the same, but fuel mileage varied. I had two identically equipped Camrys that got different mileage.

Take the first five cars, trucks, tractors, guns etc. off the assembly line on any given day and you may get different performance.

I find it hard to accept that added weight does not affect performance to some extent, but find it easy to believe the difference could be so small as to be inconsequential.

Just my :2cents:minus change.

Facts are meaningless. You could use facts to prove anything that's even remotely true! --Homer Simpson