I have had 4 Ventracs with no significant problems. The Diesel has the least power (24.9) of any of the engines offered for the 4500. I currently have the Kubota gasoline (32.5 hp) and love it.
JackIL
Be careful of the 4200 31hp turbo diesel they have major overheating problem that nobody is not standing behind. Mine is sitting in the shop now in pieces from this problem that I've been fighting since I purchased this piece, with the motor having a little over 500 hrs. on it!! There are 2 more sitting on the floor at the dealer that they are having a very hard time getting the warrantee even to pick up the tab saying that the it is their own fault that it over heated. This is being said from their head mechanic! I work with field equipment for over 35 years and know when something is wrong but they won't even listen/ saying the rad. is clogged to rinse it out. I would stay clear of any diesel engines in these pieces. Just don't have enough ***. I think that you will start hearing more about these in the future.
I do however like the setup and the Kubota GAS engines with the carb setup, many things that they offer, it helps out a lot with labor costs. I'm looking to get the 4500 z with 32.5 Kubota gas engine. Being that I have over $30,000 in options!! You can see a lot of changes in the new line of ventracs with fans on the hydros and a lot bigger radiator, which I think will be a great improvement! I'll let you know how things turn out. good luck!!