Kubota Gas vs Kubota Diesel engine option

[buickanddeere]

The other advantage of coloured off road fuel is that it shows up in fuel system of the fuel thief’s vehicle .

 

[MossRoad]

I wish that was the case here, you can not buy off road gas any where and there is no way to get the tax you paid for on road fuel or gas.
The 4500P only turn 3200 wide open and I mostly run around 3000and I have some very steep hills but nowhere some claim to be 45 degrees that is 50% or a 1 to 1... and the 4500P is rated at 30 degrees..... better have tracks on it to be that steep....jim

45 degree slope = 100% grade, not 50%.

 

[johara1]

45 degree slope = 100% grade, not 50%.

My bad, you are right but in my line of work we use 1 to 1 slope measurements Any way most don't understand steep. To make a statement that they mow up a 45 degree slope and the machine is not even rated for 30 degrees due to lubracation issues is ridiculous . I did more slope work than anyone on this forum and when you hit 1 to 1 slope you better be on tracks. Don't get me wrong you can move around some with tires but under perfect conditions. The engine needs lubracation and these little tractors don't have the rating.... jim

 

[MossRoad]

My bad, you are right but in my line of work we use 1 to 1 slope measurements Any way most don't understand steep. To make a statement that they mow up a 45 degree slope and the machine is not even rated for 30 degrees due to lubracation issues is ridiculous . I did more slope work than anyone on this forum and when you hit 1 to 1 slope you better be on tracks. Don't get me wrong you can move around some with tires but under perfect conditions. The engine needs lubracation and these little tractors don't have the rating.... jim

The engine in my PT425 is a 25HP Kohler and it's lube system is rated at 25 degrees. The Power Trac slope mowers are rated at 40 and 45 degrees, and they have tires... a lot of tires! :laughing:

45 degrees is very uncomfortable to even stand on, let alone drive up, and even worse, across like the PT slope mowers can. I have to use my hands in front of me walking up a 45. Walking down a 45 is downright painful, as my feet slip forward in my shoes and my ankles don't bend at that angle.

 

[johara1]

Again you are limited by lubracation limits due to a particular engine, but also limited by traction and grass ain't the best thing. I had a few rides on a tractor pulling a baler and a wagon when I was a kid...... jim

 

[Tony H]

I am considering the purchase of a Ventrac 4500, but am undecided on engine option. I've narrowed it to either Kubota gas or diesel. My expected use is summertime mowing/brush hogging.

My inclination is diesel, for two reasons. One is fewer problems with fuel, such as if the unit is parked for a while while the gas ages. With a diesel unit I am more comfortable letting the machine sit for a longer period of inactivity than with gas. Such as over the winter. The other reason is perceived longer life in a diesel engine. I am not as sure about that, as Kubota supposedly uses very similar blocks for both the gas and diesel engines, and each runs at 3600rpm.

The factory tells their dealers to push the gas engine, which is more powerful at 32hp. The diesel is only 25hp and is not turbocharged. I don't have a practical way to test the diesel power for my needs, but from an earlier test drive of a gas unit plus reports from diesel owners it should be fine.

Again, I am leaning toward diesel but don't like going against what the factory recommends, which is the Kubota gas engine. Have I missed anything to consider between the two engines?

What did you decide?
Kubota 3 cylinder engines .. BOTH Gas and Diesel are great. In fact I was going to pull an old Gasser out of a tired Man lift and put it in my Cub Cadet. I don't use the Front Mule for anything so adapting only a rear driveshaft would be easy.
Gas: Ethanol gas is a toughy for long term sitting unless you put a 'Shutoff' and run the gas lines out of gas when not in use. Also buy the BLUE Sta-Bil additive as it has Ethanol stuff in it that the Red stuff doesn't have . You dont need the Sta-Bil "360". The engines start very well 365 days a year , even in cold country.

Diesel: The new Diesel fuel ( low Sulfar) presents it's own long term issues. This new fuel not only costs more then Premium gas now but also is prone to Bacteria and algae growth. You will need to buy and additive for diesel now. (Biocide). Ethanol and low sulfar Diesel. Added cost at the Pump and added cost for Additives. Thanks Gov't.
Diesels last longer not only because of the lower RPM's But diesel is a lubricant. Both sides of the Pistons are seeing lubrication at each stroke. I have 30 year old gas engines on lawn mowers and they run fine. OIL CHANGES!

my 2cents

 

[scaredychicken]

thanks plowhog - because of this post and the knowledgeable responses, I have learned a lot today. I had NO IDEA that Ventrac tractors had the Kubota engines. that's great. I looked at the Ventrac 4500 earlier last year - but was still considering usage, decided on a traditional tractor (in my case, a Kubota). Interesting post

 

[sdquick]

Not exactly true. The limit is usually set at the maximum reimbursement rate the card issuer will apply toward the merchant if the charge is disputed. In my opinion, the limit sucks and here is why:

I pull in for fuel in my motor home. At 45 ft plus 21 feet for a tow vehicle I am using 66 feet in the fuel station. So I am blocking at least one other pump and likely two others. I have 20 gallons left in the tank, so I need to add 130 more gallons to fill up. Recent price was $3.15/gallon.

I swipe my card, and add fuel until it stops at $100. At this point I've put about 32 gals in, taking 8 minutes at a flow rate of 4 gallons per minute. I still need 98 more gallons.

I re-swipe my card, taking another minute, then repeat the process. When it clicks off this time, I've been impeding other traffic now for about 17 minutes. I have 64 gallons added so far, about half way.

I try to swipe the card a third time and it is declined. Only two consecutive fuel purchases are allowed. Now I need to either: a) go into the station, standing in line to work things out, or b) use my wife's card and start all over with two more consecutive fillings. Either way I am still blocking at least three fuel pumps. If I do it using her card, with two more transactions, I'm pushing 45 minutes of tying up the fuel station until I finish.

Needless to say, I try to fuel at truck stops. But that seems to work out only about 1 time in 3 or 4.

Has anyone tried calling their card company to see if this limit can be changed or increased? A few years ago I had trouble when we would travel to "the big city" a few hours away because the card would decline a purchase due to being "out of area" without having reported travel. Of course this would always happen at a Walmart after we had run a cart of stuff through the checkout with 15 people behind us in line. After the third time a told them to either include the "Big city" in my home area of cancel the card. I have not had the issue since. I wonder if the company could up your gas limit??

 

[John Joseph McVeigh]

There's more energy in a gallon of "diesel" than there is in a gallon of gas, so I'm not buying that EFI will make your gas engine as fuel efficient as a diesel.

I have a couple EFI gas motors, they work great, but they do not sip fuel like a diesel does.

SR

There are a couple of issues here. First, as you say, a gallon of diesel fuel contains more energy than a gallon of gasoline. Second, the efficiency of any internal-combustion engine depends, in part, on its compression ratio. The higher the compression ratio, the more efficient the engine will be. The compression ratio of the Kubota diesel is necessarily higher than the compression ratio of the Kubota gasoline engine and the compression ratios of the other gasoline engines that Ventrac incorporates in its tractor. (The compression ratio must be higher in the diesel engine so that combustion will occur without the assistance of an electrical spark; so high a compression ratio in a gasoline engine would result in premature detonation a/k/a pinging or engine knock.)

It is true that the Kubota gasoline-burning engine in the Ventrac Model 4500Z produces more maximum horsepower than the Kubota diesel-burning engine in the Ventrac Model 4500Y, but for the same crankshaft horsepower, the Model 4500Z's fuel consumption will necessarily be higher due to the lower compression ratio of the gasoline-burning engine and the smaller amount of energy stored in a unit volume of gasoline.

I chose the Model 4500Y in part because I did not want to have to deal with ethanol issues. (There is no nearby source of ethanol-free fuel other than the engineered fuel whose cost per gallon is substantially greater than the cost of off-road diesel, which is comparable to the cost of gasoline that contains 10% ethanol.)

I add fuel treatments to the off-road diesel fuel that I buy, but not a biocide because the fuel does not sit long enough in the Model 4500Y's fuel tank. However, I do use a biocide (Power Service Bio Kleen) in the 1,000-gallon tank that holds heating oil for my house.

I change the in-line fuel filter of the Model 4500Y every 200 hours. From visual inspection, I have never seen any algae or sludge on the filter medium.

I do not regret my choice of the Model 4500Y.

JJM

 

[4570Man]

Would it be possible build a gas motor that doesn’t spark and instead runs like a diesel? Maybe the fact it’s never been done or at least mass produced would suggest the answer is no, but why not?