As long as the manufacturer isn't on the hook for a violation of the EPA when the owner modifies their vehicle to be out of spec.

For automobiles, this has been the case - that the owner is responsible the vehicle goes out of spec... and the owner can also do a lot of customization of their vehicle.

For heavy machinery (which tractors fall into), the manufacture is almost always on the hook for any modification that the owner makes.

https://www.farm-equipment.com/articles/18110-what-you-need-...

> Here’s one real-life scenario that Natalie Higgins, vice president of government relations and general counsel for EDA, shared during a recent presentation for the United Equipment Dealers Assn. “An Ohio equipment owner purchased a tractor and then installed a turbocharger on the engine. The tractor owner sustained injuries and then sued both the manufacturer and the equipment dealer, alleging that his injuries were the result of negligence on the part of the manufacturer and dealer. Remember, neither the dealer nor the manufacturer were involved in the turbochargers installation.”

> ...

> And, if you service equipment that has been chipped, the warranty will most likely be denied and you will not be paid for your work. “That can also put your dealership in a sticky situation if technicians in the shop are not conveying to the rest of the dealership what is going in,” says Wareham. F

> Financial consequences can be harsh for not following the law. Under federal law 40 CFR § 89.1006, the penalty for a dealer who removes or renders inoperative emissions controls is subject to a penalty of $32,500 for each violation. Wareham says that one manufacturer of chipping software was initially fined $300,000 by the EPA and then $6 million to ensure future compliance with the Clean Air Act. “The EPA has stated that their intent is to crack down on defeat devices in 2020,” says Wareham.

> A dealer may face liability issues when customers tamper with the equipment they purchased, even if a dealer had nothing to do with the modification. For example, in instances in Ohio and Oregon, customers were injured as a result of modifications and dealers were sued.

I can see why that regulation would be in place though. I don't want heavy industrial machinery coming with "here's how to make it run faster and stronger but ruin the environment, which you definitely should not do wink wink."

But did the tractor owner win the lawsuit? Anybody can sue anybody. Winning is what matters. That anecdote doesn't tell me anything, and the whole article reads as FUD. I wonder if it is paid for by John Deere?