They're trying to get you to do your service exclusively at them, for powertrain issues that likely won't happen.
The odds are in their favor:
1. You're 100% guaranteeing you will do your service there (is it limited to maintenance only or everything including repairs?).
2. Your likelihood of having powertrain issues are not 100% guaranteed though.
3. Factor in the possibility you will lose the car or sell it before you have a powertrain issue.
4. Factor in the possibility something happens that they decide not to cover.
5. Factor in the possibility something happens that they decide voids your warranty coverage. A "lifetime" is a long time, any number of things can happen that they can say excuses their responsibility. Got into a car accident? Sorry, the accident must have damaged a powertrain component.
Trading 100% for odds that are far less than 100% is a rip off. It gets even worse the closer some of those odds are to zero. For example if you never have a powertrain issue at all and never end up redeeming the warranty as a result, you gave them 100% of service for 0% of warranty.
We also know that the likelihood you'll ever redeem this warranty or that they'll honor it is low. How do we know? Because they're offering it to you in the first place. If they're offering this warranty to their customer base and events that necessitate the warranty are common enough to be necessary, they'd be out of business or losing so much profit they wouldn't offer it. They're not a charity they're a business out to make money. If they're offering it to customers it's because they're making money out of it when customers bring their vehicles exclusively to them for service and the service dollars are much more than whatever they paid out for warranty. As the delta between how much they made on service and how much their paid out for warranty increases, it's better for them and worse for the customer.
They've calculated their risk out of it when they cooked this up, that's why they offered it to you. They know someone is going to be stupid enough to think it benefits them. Why would a dealer offer you lifetime powertrain warranty if it's going to cost them money and it's so good for you? They're not stupid and they haven't suddenly decided they wanted to become a charity either. They only do what makes profit for them, period. Even in the best case if they never give people a hard time about redeeming the warranty, you'd still have to redeem the warranty to actually get your moneys worth. If they scope the warranty narrowly enough then you have a decreasing likelihood you will get your months worth.
If I was you, I would decide the odds are not in my favor and not do maintenance exclusively at them.
By the way if any of this sounds familiar to you, it's because it is. It's called insurance (like auto insurance). The difference is most insurance covers things that are highly unpredictable, such as car accidents (even if you could control your behavior, you can't control other drivers or the environment), natural disasters and when you're going to die (life insurance). Compared to those, a powertrain is as predictable as it gets. It's man-made and designed by engineers to handle multiple cases and behave in a certain way provided maintenance is done.
The difference is even greater when you think about how you make payments and what for. Paying auto, homeowners or life insurance premiums aren't making it less likely you'll have to redeem those policies, but for this lifetime warranty gimmick, your "payments" are actually service on the powertrain which does make it less likely you'll have to redeem the warranty/policy in the first place! That's a gimmick.
