Tractor weight vs. fuel consumption while mowing?

[JDgreen227]

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.

 

[xtn]

Extra weight/mass only makes a difference on fuel economy during acceleration. There isn't a whole lot of that going on during mowing of large areas, so it probably won't make any noticeable difference. Also at the speeds we're talking about wind resistance isn't much of a factor either.

xtn

PS - Okay I know weight/mass also makes a difference on fuel mileage when changing the elevation of the weight/mass. But presumably when mowing you're going to shut down in the same place you started up. So you've gone down exactly as many hills as you've gone up, in effect neutralizing any difference weight/mass would have caused.

 

[RoyJackson]

There are some good reasons to remove the FEL when mowing...

I doubt fuel economy is one of the top reasons...xtn's post gives good info, and these CUTs just don't use that much fuel (unless you're mowing some major acreage).

 

[smstonypoint]

There are some good reasons to remove the FEL when mowing...

I have the SSQA on my FEL, and I have my bucket mounted only when it is needed. I figure there will be less wear/tear on my front axle, I have better visibility, and it is easier to maneuver in tight spots. However, I don't bother to remove the FEL itself.

Steve

 

[JDgreen227]

Extra weight/mass only makes a difference on fuel economy during acceleration. There isn't a whole lot of that going on during mowing of large areas, so it probably won't make any noticeable difference. Also at the speeds we're talking about wind resistance isn't much of a factor either.

xtn

PS - Okay I know weight/mass also makes a difference on fuel mileage when changing the elevation of the weight/mass. But presumably when mowing you're going to shut down in the same place you started up. So you've gone down exactly as many hills as you've gone up, in effect neutralizing any difference weight/mass would have caused.

Thanks for your input....hmmm, one of the reasons I chose my 4210 over the 4310 was because I wanted the lightest mid-chassis model with the smallest engine, mainly because I expected the lighter model to get increased fuel economy over a heavier tractor. As I interpret your reasoning, that means I could have the additional weight of the FEL installed, and have liquid weight in the rear tires, and the rear blade and weights installed, and there would be NO real difference in the fuel consumption between 5,000 pounds of machine and 3100 pounds while mowing?

 

[MoKelly]

Maybe an uniformed question ... but ... does the FEL/loader help with stability when mowing on a slope if the bucket is kept low? Maybe it just feels that way to me because I don't know any better?

MoKelly

 

[RoyJackson]

Maybe an uniformed question ... but ... does the FEL/loader help with stability when mowing on a slope if the bucket is kept low? Maybe it just feels that way to me because I don't know any better?

MoKelly

Read this thread:
http://www.tractorbynet.com/forums/owning-operating/199464-slopes-tractor-tilt.html

You'll learn more then you want to know about slopes, FELs and stability.

 

[JDgreen227]

Read this thread:
http://www.tractorbynet.com/forums/owning-operating/199464-slopes-tractor-tilt.html

You'll learn more then you want to know about slopes, FELs and stability.

Thanks Roy...I too have wondered about the subject. My reasoning was, keeping the bucket low lowers the CG, but much of the mass of the FEL itself (at least on my tractor) is mounted high, which would probably raise the CG....always wondered if they would cancel each other out.

 

[TripleR]

We have some engineers as TBN members and I am sure if they choose to focus on it we will have several definitive answers.

The problem for most of us is the inability to measure consumption. I don't keep track of how many gallons I add per hours used mowing, FEL, hauling and empty bucket v full etc.

It seems to make sense that moving less weight uses less power/fuel. The difference is "probably/possibly" like going a bit over the speed limit, the time saved is going to be noticeable on long trips, but not so much on short ones.

Sometimes I mow with FEL and sometimes without. If I am going to mow for several hours with my L5030, I remove my FEL, but I leave it on our M8540 to knock brush down.

I am not an engineer, diesel mechanic etc., so view this only as rambling thoughts.

 

[jtheise4]

Extra weight/mass only makes a difference on fuel economy during acceleration. There isn't a whole lot of that going on during mowing of large areas, so it probably won't make any noticeable difference. Also at the speeds we're talking about wind resistance isn't much of a factor either.

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.

 

[Baby Grand]

Depending on how you have the weight distributed, removing the FEL can lighten up the front axle a lot.

This is good if you don't need the added weight to keep the front on the ground when climbing a hill with a heavy brush hog cantilevered way aft of your rear axle. I think it's also good if you are mostly using 2WD to mow, as front axle weight above what you need to steer is just creating more drag.

I'd guess a lot depends on your soil conditions, too. If the soil is firm, a little extra weight probably doesn't affect fuel consumption much, but as the tires start digging into softer soil they do get a bit draggy. Ever try to push a loaded vs empty wheel barrow through soft soil? There's a big difference between tires that are "floating" on soft soil and tires that are shearing/displacing the soil.

I chose my 4210 over the 4310 was because I wanted the lightest mid-chassis model with the smallest engine, mainly because I expected the lighter model to get increased fuel economy over a heavier tractor.

- I selected my L3240 in 2007 with almost the exact same reasonong as JDgreen227. I wasn't so concerned with fuel cost as I was about fuel availability. There are some tasks that I have to have the tractor up & running to complete. If fuel availability is sketchy, then I want to be able to get those tasks done using as little fuel as possible. Sometimes smaller is more.
-Jim

 

[MoKelly]

Read this thread:
http://www.tractorbynet.com/forums/owning-operating/199464-slopes-tractor-tilt.html

You'll learn more then you want to know about slopes, FELs and stability.

Thank you. It was helpful and de-bugged my uninformed opinion.

I am really afraid of slopes but, luckily, don't have many of concern on my place. Quite frankly, I just leave them alone on the tractor and go back using a pull behind on the 4 wheeler.

Takes more time but I am happier.

MoKelly

 

[JDgreen227]

We have some engineers as TBN members and I am sure if they choose to focus on it we will have several definitive answers.

The problem for most of us is the inability to measure consumption. I don't keep track of how many gallons I add per hours used mowing, FEL, hauling and empty bucket v full etc.

It seems to make sense that moving less weight uses less power/fuel. The difference is "probably/possibly" like going a bit over the speed limit, the time saved is going to be noticeable on long trips, but not so much on short ones.

Sometimes I mow with FEL and sometimes without. If I am going to mow for several hours with my L5030, I remove my FEL, but I leave it on our M8540 to knock brush down.

I am not an engineer, diesel mechanic etc., so view this only as rambling thoughts.

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.

 

[RoyJackson]

We have some engineers as TBN members and I am sure if they choose to focus on it we will have several definitive answers.

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 manuverability and stability on my slopes).

How many gallons are you going through in a mowing season now, JDGreen227? You've got 11 acres (per your profile). Figure 10 require mowing of some sort (finish or field). How many gallons per month? Have you kept track of that?

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

 

[DAY]

Keep the FEL on, bucket low and horizontal. It works like an Indy car air dam- it reduces aerodynamic lift.
Also, replacing the rear weight box with a spoiler will generate downforce, without the added weight. A Top n’ Tilt hydraulic link will allow adjustment when plowing long straightaways, and making tight turns at the end of the field.

The effect is not really noticible under 200 mph.

 

[RoyJackson]

Keep the FEL on, bucket low and horizontal. It works like an Indy car air dam- it reduces aerodynamic lift.
Also, replacing the rear weight box with a spoiler will generate downforce, without the added weight. A Top n Tilt hydraulic link will allow adjustment when plowing long straightaways, and making tight turns at the end of the field.

The effect is not really noticible under 200 mph.

Boy, I'm really glad you added that last comment!!!

 

[SandburRanch]

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.

 

[RobKinNH]

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.

 

[JDgreen227]

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 manuverability and stability on my slopes).

How many gallons are you going through in a mowing season now, JDGreen227? You've got 11 acres (per your profile). Figure 10 require mowing of some sort (finish or field). How many gallons per month? Have you kept track of that?

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

Roy, I mow about 4 1/2 acres of yard area plus a few miles of ATV trails in the back 5 acres. Last year I logged about 80 operating hours from the end of March to the end of October (actual records kept) Most likely some of that time was devoted to dirt and rock and brush moving....yes it is very hard to calculate hourly fuel use....I do record hours per month but that is meaningless unless I know actual fuel consumption per hour.

 

[milkman636]

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".