This trucks Achilles heal has proven to be its reliability of which it fails to deliver. The truck has had several recalls and some problems that should be recalled. There have been issues with the cabs actually coming off to computer updates & more. If you like the coffee at your local service shops waiting room than this is a best bet. One of the most expensive yet common failures of this truck is a cheap seal located on the cylinder sleeve, it'll fail between 50k-150k, however though the seal is cheap it will cost $7000-$12000 to replace it as it's essentially the same work as an in frame kit rebuild. Other minor mechanical faults like leaky air tanks, air brakes that lock up, transmission failures all add to the list of mechanical problems we've had with it.There have been times when driving this truck that the wiring goes wild and lights blink gauges start bouncing etc, you shut off the truck restart it and everything is good again, very strange indeed.
What seems to have happened is that they switched to more environmentally friendly materials for gaskets & the like combined with the fact that the people who designed the DT466 are probably dead or retired ( the engine is nearly 30 years old), so the new engineers don't know whats going on (speculation). International has also had a recent bad reputation for making the Ford 6.0L diesel engine. After several recalls and lawsuits in just a couple years Ford ditched the 6L in favor for their own in-house designed 6.4L, this to me speaks volumes at the current state of IH.
Some of the better features of the truck is the cabin & exterior, they're decently attractive & modern. The interior dash is especially nice when compared to the 4700 which this replaced. The ride is a bit rough on pot holed roads but that's expected with a truck like this. It's common to hit a bump too hard and fly off your chair. The radio is nice with good quality speakers, the A/C blows ice cold and there's plenty of storage above your head and around for any work related paperwork etc.
Fuel economy has been a modest 8-12mpg due to the variable vain turbo charger.
To conclude though attractive and modern, the DuraStar/4300 lacks in the most important feature of a commercial truck, reliability, the last thing you want in the portable toilet business is to leave your customers hanging, and this thing has on several occasions.