Any news on gas engine CUTS?

[AxleHub]

I really don't get the logic that a gas engone tractor is at all competitve with a similar sized diesel engined tractor:

1. Similar hp for gas and diesel does not equal similar power or torque. Diesel performance per horsepower in terms of torque and DURABLE power is substantially greater.

2. Use of fuel in diesel is substantially more efficient AND effective than gas.

3. A gas engine's maontenance requirements are more ftequent and more neccessary than is diesel.

4. Initial cost on a diesel engine is higher . . But its mean time to failure and fuel efficiency more than makes up on a busy engine.

5. While numbers can be run in many ways . . A gas engine under sustained load does not compare to a diesel engine under that same sustained load . . . unless that gas engine is of considerable larger size of hp, extended cooling options, and larger engine cavity/dimension.

I have a 25 horse gas in a ztt and a 25 horse diesel in my sub compact. There is no contest as far as fuel usage or continually produced power or ability to deal with enviromental stresses.

 

[batwing]

I had a 165 Massey with a gas motor for about 6 years, plenty of torque and horsepower, I would have bought a new gas tractor with hydro if there was a real gas engine available. I would not buy one with a lawnmower engine even if they said it had 50hp. it looks like most small tractors get used about 50 hours per year.

 

[GManBart]

Depends on what you are going after. Weight is often the enemy for mowing as you want as little turf damage as possible. Ditto with any kind of operating in wet areas unless you want to make big ruts. Tillage however is the opposite, you want to have as much weight for as much traction as possible. Loader work is a mixed bag. You want enough weight to remain stable (hence counterweights) but it would be better if the weight were in the rear of the tractor rather than on the front.

Sure, it's situational, but most folks aren't using a CUT on their lawn, so that probably narrows the discussion down to SCUTs...at least when we start wondering if lighter might be better.

No. Diesel engines in every other application cost more than analogous gasoline engines in the same usage scenario- generators, mowers, pumps, automobiles, light and medium duty trucks. Tractors would be no different.

There are gasoline engines designed to run at "PTO speed" all of the time- namely pump engines, commercial generator engines, inboard boat engines, and piston-powered aircraft engines. The big difference between those engines and an automotive engine is that they have a lower redline and thus a lower peak power rating. A car engine may redline at 6500 rpm but it is mainly designed to operate in the 2000-3000 rpm range. The industrial engines are simply governed at somewhere in that 2000-3000 rpm range...just like the diesel engines are.

Well, I never said diesels would't cost more, I just said the gap would narrow. Generally speaking, nobody makes a gasoline engine, with the most modern features that are required to really get good efficiency like the folks in this thread are talking about, in a package truly equivalent to the diesel engines we're using as a benchmark. If you look at the engines used in generators, or inboard boat engines, or medium duty trucks and compare gas to diesel, it's pretty much a given that the diesels are intended to last longer, and survive more difficult duty cycles. In other words, if you buy the version with the gasoline engine, you know it's not going to last as long as the diesel, and that's why it costs less. If someone wants a 40' sport fishing boat they can get it with gasoline engines, or diesel engines, but nobody expects the gasoline engines to last anywhere near as long, or be anywhere near as fuel efficient.

I would leave out references to aircraft piston engines....they're a completely different animal. They're designed to be as light as possible, and require extensive maintenance on a regular basis....and they still fail with regularity.

As has been said many times in this thread....comparing modern diesel tractor engines to pretty much any known gasoline engine is going to be an apples-to-oranges comparison. If someone decided to make an engine that could be expected to perform reasonably as well as it's diesel counterpart, and have a similar service life, the cost difference between the two wouldn't be nearly as big as we see in things like commercial light trucks, or boats, or anything else.

I see very few diesel ZTRs around here. Nearly all of them are gasser Deeres and Gravelys. Finish mowing is often the heaviest load people will put on a SCUT or CUT and it is absolutely a sustained load. You won't use 25 PTO HP doing loader work but you certainly can with a decent-sized mower. The fact that you can bog down a tractor with a mower speaks to the fact that they can take a lot of power to swing.

I see a lot of mom and pop landscape people running gasser ZTRs, but all the bigger places seem to be running diesels around here...SCAG, Farris, Hustler, Kubota and Deere.

I'm not sure what kind of finish mowing you've been doing, but I ran a 90" finish mower behind 40hp PTO and it was like it wasn't even there. Running my 87" flail mower behind 45hp PTO is far, far more heavily loading the machine, and even a 60" medium/heavy duty rotary mower put more of a strain on either machine than the 90" finish mower. I'd expect any reasonably sized tiller, snow thrower or even post-hole digger would put more of a strain on the machine. A couple of 12-24" blades going through grass shouldn't cause nearly the resistance that heavy brush, dirt, or snow would.

 

[AxleHub]

Sure, it's situational, but most folks aren't using a CUT on their lawn, so that probably narrows the discussion down to SCUTs...at least when we start wondering if lighter might be better.

Well, I never said diesels would't cost more, I just said the gap would narrow. Generally speaking, nobody makes a gasoline engine, with the most modern features that are required to really get good efficiency like the folks in this thread are talking about, in a package truly equivalent to the diesel engines we're using as a benchmark. If you look at the engines used in generators, or inboard boat engines, or medium duty trucks and compare gas to diesel, it's pretty much a given that the diesels are intended to last longer, and survive more difficult duty cycles. In other words, if you buy the version with the gasoline engine, you know it's not going to last as long as the diesel, and that's why it costs less. If someone wants a 40' sport fishing boat they can get it with gasoline engines, or diesel engines, but nobody expects the gasoline engines to last anywhere near as long, or be anywhere near as fuel efficient.

I would leave out references to aircraft piston engines....they're a completely different animal. They're designed to be as light as possible, and require extensive maintenance on a regular basis....and they still fail with regularity.

As has been said many times in this thread....comparing modern diesel tractor engines to pretty much any known gasoline engine is going to be an apples-to-oranges comparison. If someone decided to make an engine that could be expected to perform reasonably as well as it's diesel counterpart, and have a similar service life, the cost difference between the two wouldn't be nearly as big as we see in things like commercial light trucks, or boats, or anything else.

I see a lot of mom and pop landscape people running gasser ZTRs, but all the bigger places seem to be running diesels around here...SCAG, Farris, Hustler, Kubota and Deere.

I'm not sure what kind of finish mowing you've been doing, but I ran a 90" finish mower behind 40hp PTO and it was like it wasn't even there. Running my 87" flail mower behind 45hp PTO is far, far more heavily loading the machine, and even a 60" medium/heavy duty rotary mower put more of a strain on either machine than the 90" finish mower. I'd expect any reasonably sized tiller, snow thrower or even post-hole digger would put more of a strain on the machine. A couple of 12-24" blades going through grass shouldn't cause nearly the resistance that heavy brush, dirt, or snow would.

Don't forget Toro, Dixie Chopper and Grasshopper diesels in the ztr arena.

 

[GManBart]

Don't forget Toro, Dixie Chopper and Grasshopper diesels in the ztr arena.

Sure...I just don't see as many of those locally. Of those three, probably more Dixie Choppers and almost no Grasshoppers, but a few Toros here and there.

 

[AxleHub]

Sure...I just don't see as many of those locally. Of those three, probably more Dixie Choppers and almost no Grasshoppers, but a few Toros here and there.

I wss very impressed with the grasshoppers made in u.s. talk about an easy to maintain group of products with a ton of flexibility on grass or snow.

 

[buickanddeere]

Agreed. Gas would not hold up with the demands of torque requirements on tractors. Would consume a lot of fuel with little payback.
If you don't like the new engines I would look at a 5 year old tractor.

Torque requirements ? A natural aspirated gasser tractor engine has more torque per cubic inch than a diesel per cubic inch. Look at the JD 4020 specs for example . A lot of fuel? A modern direct injection gassed use a lot of fuel? Have you looked at the part load fuel consumption of Diesel engines .

 

[buickanddeere]

I really don't get the logic that a gas engone tractor is at all competitve with a similar sized diesel engined tractor:

1. Similar hp for gas and diesel does not equal similar power or torque. Diesel performance per horsepower in terms of torque and DURABLE power is substantially greater.

2. Use of fuel in diesel is substantially more efficient AND effective than gas.

3. A gas engine's maontenance requirements are more ftequent and more neccessary than is diesel.

4. Initial cost on a diesel engine is higher . . But its mean time to failure and fuel efficiency more than makes up on a busy engine.

5. While numbers can be run in many ways . . A gas engine under sustained load does not compare to a diesel engine under that same sustained load . . . unless that gas engine is of considerable larger size of hp, extended cooling options, and larger engine cavity/dimension.

I have a 25 horse gas in a ztt and a 25 horse diesel in my sub compact. There is no contest as far as fuel usage or continually produced power or ability to deal with enviromental stresses.

Are you living in 1975 or 2015 ?

 

[buickanddeere]

Sure, it's situational, but most folks aren't using a CUT on their lawn, so that probably narrows the discussion down to SCUTs...at least when we start wondering if lighter might be better.




Well, I never said diesels would't cost more, I just said the gap would narrow. Generally speaking, nobody makes a gasoline engine, with the most modern features that are required to really get good efficiency like the folks in this thread are talking about, in a package truly equivalent to the diesel engines we're using as a benchmark. If you look at the engines used in generators, or inboard boat engines, or medium duty trucks and compare gas to diesel, it's pretty much a given that the diesels are intended to last longer, and survive more difficult duty cycles. In other words, if you buy the version with the gasoline engine, you know it's not going to last as long as the diesel, and that's why it costs less. If someone wants a 40' sport fishing boat they can get it with gasoline engines, or diesel engines, but nobody expects the gasoline engines to last anywhere near as long, or be anywhere near as fuel efficient.

I would leave out references to aircraft piston engines....they're a completely different animal. They're designed to be as light as possible, and require extensive maintenance on a regular basis....and they still fail with regularity.

As has been said many times in this thread....comparing modern diesel tractor engines to pretty much any known gasoline engine is going to be an apples-to-oranges comparison. If someone decided to make an engine that could be expected to perform reasonably as well as it's diesel counterpart, and have a similar service life, the cost difference between the two wouldn't be nearly as big as we see in things like commercial light trucks, or boats, or anything else.



I see a lot of mom and pop landscape people running gasser ZTRs, but all the bigger places seem to be running diesels around here...SCAG, Farris, Hustler, Kubota and Deere.

I'm not sure what kind of finish mowing you've been doing, but I ran a 90" finish mower behind 40hp PTO and it was like it wasn't even there. Running my 87" flail mower behind 45hp PTO is far, far more heavily loading the machine, and even a 60" medium/heavy duty rotary mower put more of a strain on either machine than the 90" finish mower. I'd expect any reasonably sized tiller, snow thrower or even post-hole digger would put more of a strain on the machine. A couple of 12-24" blades going through grass shouldn't cause nearly the resistance that heavy brush, dirt, or snow would.

We have people here who do not understand the difference between light duty applications and heavy duty applications . Nor are they aware of direct injection gasoline engines, tied IV diesel emissions and glow plugs, 30,000psi injectors or pumps, egr valves, egr coolers , urea injection , particulate filter regeneration . They are thinking of carbureted gas engines with points vs an inline diesel with just a P pump and a turbo. With diesel costing 3/4 the price of gasoline .
A DI gasser will make just as much power per btu of fuel than a diesel.
Part throttle, part load applications a gasser absolutely stomps all over a diesel's part load efficiency . That is why they are used in light highway vehicles.

 

[buickanddeere]

Given the upcoming Tier V emission regulations limiting CO2 output . Fuels with more hydrogen and less carbon such as NG, LP and gasoline vs carbon heavy diesel. Equipment Manufactures will have to consider the same strategy as automotive manufactures. Build the same chassis with diesel for 3rd world no emissions countries and for where gasoline is taxed higher than diesel. Sell the same chassis with a gas engine in North America.
Right now manufactures keep their market share in 3rd world countries and over taxed gasoline countries by selling the diesel . North Americans are rich by comparison and will pay for the emissions equipment added to a diesel . Cheaper and more profitable than building gassers for the limited North American market. Many people forget that the U.S. Is not the only significant market in the world.