Extended warranties are almost pure profit.
The dealer probably gets 1/3 up front as a commission and they wouldn't do that if the manufacturer wasn't getting about the same.
So on average they pay out about 1/3 in claims. Compare that to life, health or auto insurance and it's not even in the same ball park.
Plus if you get in an accident and total the truck, decide to sell or otherwise liquidate the truck, you get nothing back (no there isn't any significant resale value for the extended warranty).
As someone else suggested, if you have a major engine failure, good chance they treat it as a totaled truck and give you a check for wholesale (ie: low ball) price and walk away with your truck.
The vast majority of time, you will be far better off to simply set the cost of the extended warranty aside and use that to pay for repairs
