Generally, "delivery truck" is not capitalized. This is because it's a common noun describing a type of vehicle.
However, there are a few exceptions:
* If "delivery truck" is part of a proper noun: For example, "The Acme Delivery Truck" would capitalize "Delivery Truck" because it's part of the company name.
* If it's used as a title: If you're writing a book or article titled "The Life of a Delivery Truck," then you would capitalize "Delivery Truck."
Example:
* Not capitalized: "The delivery truck pulled up to the curb."
* Capitalized: "The Acme Delivery Truck was bright red."
* Capitalized: "The book 'The Life of a Delivery Truck' was a bestseller."