Tractor Performance: diesel vs gas

[Soundguy]

I thought somebody already dispelled the myth that diesels use 50% less fuel than a gasser...

Can't remember the page.. but someone posted the #'s of btu's per gallon of fuel. there was certaintly a difference.. but not twofold..e tc.

soundguy

 

[john_bud]

These acerbic quips are uncalled for and truly detract from the threads here.

I'm going to make an adjustment that will greatly increase the reading pleasure for myself anyway..

{click}

Ahh.. that's better.

soundguy

Somebody just got put on the "ignore" list. What a wonderful invention....

jb

 

[Matt_Jr]

I don't know the percentage of differences in fuel economy between gas and diesel but we all know there is a difference and diesel wins. Diesel wins in power too when involving tractors. Even A V12 diesel is being used in racing that is blowing away the competition. When comparing equally matched horsepower ratings of engines diesels win in torque every time.
Example. HP=torque x rpm/5252. Torque=hp/(rpm/5252).
A 22hp gasser that gets peak hp at 3600 rpm has 32 ft/lbs of torque. A 22 hp diesel that is rated at 3200 rpm has 36 ft/lbs of torque. Yes, a very small differance but still a differance. Play with the numbers when using higher and lower hp ratings and you'll see where the advantages of diesels really shine in torque. The formula used is the same formula dynomometers use to calculate hp from torque measured. The rpm's used are from Kohler, Briggs n Straton engines and kubota diesels.

Yes older diesels can be a little bit uncooperative in extremely cold weather, but that can be over come with a little upgrading and preperation. Ever had a choke problem on an old gasser? How 'bout a float stick? How 'bout a bad temp sensor on a fuel injected engine? Map sensor? MAF sensor? Coked throttle body? Bad PCV valve? Vacuum leak?

I know gas engines can be reliable if maintained properly but that's the point. When these things go bad it's when you need them most. I know, I fix'em for a livin'. Diesel engines are just plain reliable. I don't have to fix very many diesels. 99.9% of what I fix is powered by gasoline and it's not 'cause my customers don't have diesels either.

Since a diesel engine spins at rpm's that are much lower than a gasoline engine it will last that much longer. Can you get 300,000 miles out of a gasser. Sure, but how many tune ups are required. How much more fuel did it use. If I had to do it over again my truck would be a diesel. I wish my Prius was.

Yes diesel parts are more expensive. A diesel engine is the same to rebuild as a gas. The parts are just a bit heavier. Other than initial cost and having to bleed the fuel system if you run out of fuel I can't think of a single reason why a modern gas powered engine would be better than a diesel.
Time for a peanut butter and jelly sandwich.

 

[genusCastor]

Thanks for all the responses. It's been good to hear all the opinions. I think I'm gonna do a diesel, maybe mostly just because I haven't had much experience with them and I'm curious.

Plus I want to sniff some good stuff while I'm tractorin'.

- djb

 

[Egon]

Somebody just got put on the "ignore" list. What a wonderful invention....

And just for asking a question??

 

[patrick_g]

Thank God for fuel injection and electronic ignitions is my point of view, if I never see another carburetor or set of points in my lifetime it'll be too soon.

And I am quite sure there are many others who will say the same thing.

Amen. Although the highest level of automotive technology I possess as regards "tune up type stuff" is setting the mechanical valve lifters on an air cooled VW, setting the ignition advance and such after putting in new points, plugs, and condensor in the VW but I'm not as proficient with the carb.

I can do the VW. It is the highest level of automotive tuning I am proficient at. I'd prefer hydraulic lifters and pointless electronic ignition (which is available after market for VW.)

If it has to work hard, then it is diesel for me. Whether or not I can personally rebuild an engine is not an issue. I have rebuilt Chevy 6 and a Willys 4 and would be happy to not do it again. It was fun, I was young, but have better things to do now.

Pat

 

[MossRoad]

Cub Cadet. I didn't see where you had specified ag/utility.. or i wouldn't have offered that as a possibility. But CC did have a ? big scut.. or small cut as a gasser. In the late 90's I remember looking at one at an agco dealers lot... cute.. and I like things with spark plug wires... I can usually get them to run without any (high magic)..

soundguy

Cub still had a gasser in 2001 I believe. That is the year I bought my Power Trac PT425, which is also gas, although not a "real" tractor, but still outworks any diesel tractor of the same size and weight except in plowing dirt, which I do not do.

 

[MossRoad]

they start INSTANTLY

Maybe in VA... probably not in IN at -20 on the coldest day of the year when you need it to work the most.

 

[MossRoad]

Thanks for all the responses. It's been good to hear all the opinions. I think I'm gonna do a diesel, maybe mostly just because I haven't had much experience with them and I'm curious.

Plus I want to sniff some good stuff while I'm tractorin'.

- djb

I think you are making the correct decision, but not because you want to sniff the fumes.

 

[flusher]

Cub still had a gasser in 2001 I believe. That is the year I bought my Power Trac PT425, which is also gas, although not a "real" tractor, but still outworks any diesel tractor of the same size and weight except in plowing dirt, which I do not do.

Today CC offers the 5252 with a 25 hp air-cooled Kohler gas engine and the 5254 with a 25 hp liquid-cooled Kawasaki gas engine

cub cadet lawn mowers

These things have Cat 1 3pt hitch, rear and mid-ptos, hydrostatic drive and ROPS.

Are these CCs true SCUTS or glorified lawn and garden tractors? Your guess is a good as mine. My 21 hp (engine) Kubota B7510HST diesel has the same stuff and definitely is considered to be a SCUT.

 

[Soundguy]

The one I saw back in the late 90's was an actual tractor.. not a lawn mower.. I don't have the model number though.. If I had to guess it was perhaps a lil larger than a NH TC-18 frame size.. though maybee like a tc 21??.. anyway.. that size of machine.. was 2wd, with regular tractor ag tires int he back..e tc.. kind about the size of a jinma 25hp machine..e tc..

soundguy

 

[john_bud]

And just for asking a question??

Maybe for asking on too many? All I know is that it really helps keep the conflict down when you don't see the other persons posts!

jb

 

[Egon]

Yep it would John. It would also insure that one doesn't have to look at any other opinions or ideas that one may not agree with.

You should go back and read the thread more carefully!

 

[RobJ]

Injector pumps have a longer life cycle than a carb,

I have an issue with this statement, there are maybe 4 moving parts in a carb, choke, butterfly, needle, float. 99% of the time you can rebuild a carb without any gaskets if you are careful, if you are not, it's $2 for a gasket, $3 for a needle. Ocassionally a float that springs a leak.

Little water, dirt in a carb, just blow it out, in an injection pump, it'll waste it. It's a lot more complicated.

 

[RobJ]

Are you not confusing the fuel with the new emissions systems that regenerate themselves by using fuel to burn off accumulated soot?
I may be mistaken, but I think it is the engines that are less fuel efficient by virtue of their new anti-pollution devices, not the ULSD fuel itself.

I think realistically you have to put the 2 together. You can 't buy a new truck without the new emissions on it. And if you remove them, you might not get it inspected. And from I understand, tractors and other things will follow as the EPA expands the ULSD rules on diesel engines. Probably some sort of hp range, weight, etc.

 

[RobJ]

the carburetor and points, are the two things that I miss the least about old gas engines.

Make sure you put the old in BOLD here. point went away a long time ago for most engines. I have an old 1974 Merc 9.8, electronic ignition. HEI ignitions came out in GM cars around 74-75 I think.

Funny how parts for a 50yo tractor or Jeep are real easy to come by.

 

[RobJ]

That is the year I bought my Power Trac PT425, which is also gas, although not a "real" tractor, but still outworks any diesel tractor of the same size and weight except in plowing dirt, which I do not do.

Ut oh, gasser outworking any diesel tractor.....

to some thems is fight-n words!!

 

[SnowRidge]

Cub still had a gasser in 2001 I believe. That is the year I bought my Power Trac PT425, which is also gas, although not a "real" tractor, but still outworks any diesel tractor of the same size and weight except in plowing dirt, which I do not do.

From Wikipedia: A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction.

So how is a PT-425 not a real tractor? What else would you call it?

It's not large, and it's not conventional, but it is certainly a tractor.

 

[Soundguy]

I have an issue with this statement, there are maybe 4 moving parts in a carb, choke, butterfly, needle, float. 99% of the time you can rebuild a carb without any gaskets if you are careful, if you are not, it's $2 for a gasket, $3 for a needle. Ocassionally a float that springs a leak.

Little water, dirt in a carb, just blow it out, in an injection pump, it'll waste it. It's a lot more complicated.

Awe shucks.. lets not interject any reality into this opinion based thread now!

( Takes 10 seconds to solder a pinhole in a float..) I'm not sure what aprt of an injector pump I can solder to fix?? )

soundguy

 

[Soundguy]

From Wikipedia: A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction.

So how is a PT-425 not a real tractor? What else would you call it?

It's not large, and it's not conventional, but it is certainly a tractor.

Conventional seems to fit. It's kind of a crossover from light industrial to agricultural...

soundguy