Diesel versus gas horsepower

[presnewt]

I have read that a lower hp diesel engine has virtually the same power as a higher hp gas engine. Is that true? What are major advantages of either? I know most large tractors are diesel, most zero turn mowers seem to be gas. I am looking at a 25 hp diesel compared to a 32 hp gas, both kubota. Thanks

 

[davesl708]

Horse power is horse power. The advantage of a diesel is a higher and longer torque curve. With the better torque curve you can perform more work.

 

[Mysfyt]

And I'll add that the hp is made at a lower rpm than a gas engine which leads to a longer life expectancy.

 

[Everhard]

And less fuel burned to perform the same amount of work? (more efficient.)

E.

 

[4570Man]

I have a gas ZTR with a Kohler V-twin rated at 25 hp and a Kubota F series powered by a 3 cylinder diesel rated at 25 hp. The diesel is turning a 10" wider deck and can't be bogged down. I'd put my 17 hp diesel lawn tractor with a 60" deck as a closer match for the Kohler. The gasser is easily bogged down on anything except thin yard grass. Not only does the diesel kick the gassers as$, it burns 1/3 the fuel doing so. My Grandpa has a 3500 diesel that tows way better than my F-350 gasser.

 

[Egon]

There is no general answer to your question. It has to be looked at on an engine to engine comparison.

In recent times there have been many changes to engine design making the old standard responses applicable to only old engines.

 

[GManBart]

Oh boy, another gas versus diesel thread. Unfortunately, it won't take long before one or two of the usual suspects show up and the debate will start. :shocked:


This thread has 60 pages of that topic if you want compare/contrast the engine types in a similar application:
http://www.tractorbynet.com/forums/...-gas-engine-cuts-post4020361.html#post4020361

There really isn't an easy answer to your question, and even then we'd need to know the exact models you're comparing. If you provide that, it's probably possible to give you an idea of the relative strengths and weaknesses for both machines.

 

[prs]

The Kubota 3 cylinder 32.5 HP rated gasoline engine is very good and will last if cared for, but you can see what your manufacturer thinks of the difference given the diesel is rated lower HP, but expected to do the same job. Some of that difference is probably due to the emission control add on that would be required if the diesel HP were higher, but still there is some truth in the comparison.

prs

 

[Gary Fowler]

Diesel engines generally develop their HP with less fuel also. Years ago, diesel engines lasted much longer than gasoline engines, but todays gasoline engines seem to give diesels a run for the money as for as duration of life, albeit not usually as long, dollar for dollar invested, I think gas engines are a good buy. Unless you are routinely pulling a large, heavy trailer, I cant see the benefit of having a diesel engine in a pickup truck. They cost a small fortune over a gas engine, take triple the oil to change, hard to start in cold weather, make a heck of a racket when running and require the urea additive in addition to fuel to run, all extra maintenance and operating factors that negate any extra fuel mileage that you may get. Per claims, todays gas engines get as good MPG as diesels so unless you need the extra lugging power of a diesel, why go to the extra expense buying one!!!

One big thing in my mind for a diesel engine in things other than automobiles is the storage factor. Diesel driven equipment can set for long periods without worrying about fuel degradation which is good for things like generators that don't get used very often.

I had an old JD 332 lawnmower with 19HP diesel engine that would cut and travel just as fast as my 26 HP gas engine mower. While true that HP is HP, some of the small engines HP seems to be exaggerated and IIRC some lawsuits were involved with claims that small engine manufactures were lying about their actual HP which resulted in some settlement monies being paid out so I think todays small engines might be more accurately labeled.

 

[4570Man]

Oh boy, another gas versus diesel thread. Unfortunately, it won't take long before one or two of the usual suspects show up and the debate will start. :shocked: This thread has 60 pages of that topic if you want compare/contrast the engine types in a similar application: http://www.tractorbynet.com/forums/buying-pricing-comparisons/329890-any-news-gas-engine-cuts-post4020361.html#post4020361 There really isn't an easy answer to your question, and even then we'd need to know the exact models you're comparing. If you provide that, it's probably possible to give you an idea of the relative strengths and weaknesses for both machines.

At least this was a diesel versus gas thread. BuickandDeer hijacks a thread even chance he gets.