3 cylinder engine vs 4 cylinder engine

   / 3 cylinder engine vs 4 cylinder engine #1  

thunder86

Silver Member
Joined
Sep 9, 2019
Messages
139
Location
Southern Indiana
Tractor
Bobcat ct4045
I just noticed a bobcat ct 4045 only has a 3 cylinder engine. Looking at kubota's similar weight/hp class with L4701 is a 4 cylinder engine. How much power difference is this between the two?
Also I've noticed bobcat has bigger hydraulic flow which means a loader and backhoe should move faster?
I've also read where the Bobcats lift capcity on the specs is off as it doesn't include the loader weight. The lift is actually minus the loader weight. Are all tractor specs like this?
 
   / 3 cylinder engine vs 4 cylinder engine #2  
Generally all loader specs are without any attachments. So if your loader says it can lift 1000lbs, has a 200lb bucket, it has an extra 800lbs to lift. Some specs have different amounts for lift capacity at the pin and another for 24 inches or so forward of the pins-the typical edge of a bucket. This is important to consider since the loader is basically a huge moment arm.
 
   / 3 cylinder engine vs 4 cylinder engine #3  
I just noticed a bobcat ct 4045 only has a 3 cylinder engine. Looking at Kubota's similar weight/hp class with L4701 is a 4 cylinder engine. How much power difference is this between the two?

I have had three cylinder diesel engines in tractors and four cylinder diesel engines in tractors. In the simplest terms I prefer three cylinder, naturally aspirated engines simply because there are fewer parts to go wrong.

Note that Kubota uses just one four cylinder engine in the L4701 (naturally aspirated), MX series (turbocharged) and all the Kubota Grand L tractors (some naturally aspirated, some turbocharged), less the three cylinder L3560.
As one who used to study the efficiency of winery bottling lines I can tell you long production runs lower unit volume costs by significant $$. Same for tractor engines production runs.

You can easily determine the factory stated horsepower but it is difficult to determine if spec is for gross or net horsepower. All engine horsepower has to pass through the tractor transmission before it can accomplish work, which varies from 8% to 20% power loss. Therefore PTO horsepower will give go the most useful information for comparing tractor functional power output ~~~ but few consumers researching compact tractors are interested in this spec.

Deere 5075E has the most powerful three cylinder diesel engine I know of. Approximately 20% power loss from engine to PTO.

John Deere 5075E Engine​



John Deere 5075E tractor photo
2008 - 2022
Model year 2008-20122013-20142015-2022
5E Series
Utility tractor
Series:5065E5075E5083E
Engine Detail
John Deere PowerTech 3029H
turbocharged diesel
3-cylinder
liquid-cooled
Displacement:179 ci
2.9 L
Bore/Stroke:4.19x4.33 inches
106 x 110 mm
Rated Power (EC 97/98):75 hp
55.9 kW
PTO Power (Claimed)61 hp




Also I've noticed bobcat has bigger hydraulic flow which means a loader and backhoe should move faster?

I've also read where the Bobcats lift capcity on the specs is off as it doesn't include the loader weight. The lift is actually minus the loader weight. Are all tractor specs like this?


All 'regulars' contributing to T-B-N grope for accurate information.

No governement agency directly polices published tractor specs. Nor are there agreed industry standards. "Trade puffery" is legal. Fraud is not.

The comprehensive Nebraska state tractor tests show Nebraska measured results but almost all tractors tested are Big Ag tractors. Few compact category or utility category tractors are tested.


Take some time to research the service reputations for your local tractor dealers. Also research the service reputations of local welding shops.


A quality dealer, reasonably close, available for coaching, is important for tractor neophytes. Most new tractors are delivered with a glitch or two requiring correction. My kubota dealer is six miles away. I feel my local dealer continues to add value to my equipment after eight years. Dealer proximity is less important for those experienced with tractors and qualified to perform their own maintenance.
 
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   / 3 cylinder engine vs 4 cylinder engine #4  
I really prefer a 4 cyl. over a 3 cyl., but I can't say I've had any problems with the 3's...

SR
 
   / 3 cylinder engine vs 4 cylinder engine #6  
3 cylinder engines tend to be more fuel efficient relative to their torque output than a 4cyl. A 4 needs higher rpm to make up for this.


Generally
 
   / 3 cylinder engine vs 4 cylinder engine #7  
Despite several requests and starting 22 research threads I note you have yet to make your LOCATION part of your T-B-N PROFILE.

I find it difficult, sometimes impossible, to post solid information without knowing where the OP will operate the tractor.

Here are my reasons for wanting OP location.

ALTIITUDE - Tractors lose 3% of engine power output for every 1,000' altitude increase, over 1,500' Sometimes twenty posts will be made advising on tractor horsepower, then we find OP is a 6,500 feet altitude and is considering a low power, naturally aspirated tractor.

WEATHER - ESPECIALLY SNOW - Blowing snow and mowing are the two tasks that require considerable engine power. If we know an OP is in Buffalo, NY rather than Key West, FL snow needs are apparent.

WEATHER - Large swathes of the country have a continental climate, four seasons, with great temperature variations between winters and summers.
Areas near the coast have less varying maritime climates.

PRICING - Tractor and implement pricing and dealer service pricing varies a great deal. Lowest prices are usually in the south. Prices along the west coast and in the northeast higher, Alaska, Hawaii and Guam highest.

Some states exempt agriculture and forestry equipment from state sales taxes. Florida is one example of liberal ag sales tax exemptions.

IMPLEMENTS - Availability of implements brands are regional, not national. ie: CountyLine, Rural King, etc.

SOIL AND GROWING SEASON - Whether game food plots or market crops, soil and length of growing season(s) in important. Soil type influences tire selection.

USED TRACTORS - When the OP posts a location, OP is often referred to good used tractors nearby or provided local tractor listings from Craig's List, eBay, TractorHouse, Machinery Peter or other sites.

Everyone on T-B-N has a screen name, as anonymous as they like. Any other profile information is contributed voluntarily, such as age and tractor brand/model. Relative to the massive data heists reported so often, with names, address, Social Security and credit card numbers stolen, this site is nearly anonymous.
 
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   / 3 cylinder engine vs 4 cylinder engine #8  
No one-size-fits-all comment or solution!

I've got 3cyl, 4cyl and 6cyl diesels (and thought about acquiring an 8cyl one). ALL are great. Most are turbocharged (with computer controls for management [my cars are over 20 years old and 200k miles and haven't skipped a beat- turbos and computers all original]).

I'll take a bullet-proof anything cyl over a not-so-bullet-proof something cyl. Bullet-proofing happens by way of engineering and materials selection (and QA). Theory is great for conversations, but the money's on the results.
 
   / 3 cylinder engine vs 4 cylinder engine #9  
I have 3 - 3 cyl diesels, 2 - 4 cyl diesels, 1 - 6 cyl & 1 - 8 cyl. One noticeable difference is the 3 cylinders shake a lot more at low idle. Other than that, they all do their job well so number of cylinders makes no real difference in performance. In theory, 3 cylinders have lower friction loss for equal displacement but for small engines it’s hard to get info like that available in the Nebraska tests. My career was engineering, much of it engine application and testing. When I started with my last company, I installed a 4 liter 4 cylinder engine rated at 107 HP, highest power rating available for that engine. Now primarily with improvements in fuel systems, that same engine is rated up to 225 HP. Yes, the lower end is beefed to handle the load, and virtually every part has changed, but the bore and stroke remain constant. Benefit is that 4 cylinder engines are less expensive to produce than 6 cylinder engines so lopping off 2 cylinders, allows a smaller engine to be used compensating for the cost of emissions add ons. And we could raise the price claiming emissions made it so while pocketing the difference. Nothing beats taking them out and trying them.
 
   / 3 cylinder engine vs 4 cylinder engine #10  
An inline 3-cylinder is much smoother than an inline 4-cylinder due to the firing pattern and inherent balance of the engine. Power and torque would be a function of the displacement and bore/stroke. If able to get apples-to-apples with engine output, I'd choose a 3-cylinder over a 4-cylinder any day.

Kubota had a couple 4-cylinder models that were famously rough and buzzy. The B3200 was one of them, with a 1.5L 4-cylinder. If you moved up in the lineup to something like an L or Grand L, the next-size bigger tractors had 3-cylinder motors. For example, the L3200 had a 1.5L 3-cylinder, the L3560 had a 1.8L 3-cylinder. That was an upgrade in every way, not a downgrade.
 
 
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