Tires

Absolutely so long as they are the same size tire.

A tire looses 1 psi for every 10 deg F drop in temperature. Tire pressure should be checked a minimum of every 30 days.

This is a pretty broad question so forgive my a broad response. You can get a low profile tire for just about any wheel size you want. The standard truck tire is an 11R22.5 the corresponding low profile size is the 295/75R22.5.

John -

This is too complex of a question to offer a simple number. Each P&D fleet will have a different average mileage life. The mileage is dependant on a number of issues, route factors like long runs or short runs, road conditions, and climate. Other factors such as maintenance practices and driver skill also impact mileage. The mileage distribution from fleet to fleet can vary from 5k miles to 100k miles using the same tires. So offering you an "average" number is not possible.

The G647 currently comes in two different compound options the G647 RSA which is being phased out and the G647 RSS. The RSS has a new tread compound for improved tread life which will also impact mileage.

Your best bet for selecting tires for your application is to compare different tires using similar trucks, driven on the same routes, with equally skilled drivers and you will find that the G647 performance is worthy of the Goodyear name.

Each manufacturer has their own proprietary method for calculating the footprint shape which drives even tread wear. This may explain why you have not had any luck in your quest. However, many manufacturers, Goodyear included, publish the gross contact area for their tires in their engineering data books. See www.goodyear.com/truck for a copy of Goodyear's book.

Briefly consulting the Goodyear book for the G314 11R22.5 trail tire the gross contact are is listed as 62 in^2. The gross contact area does not subtract out for any grooves.

Good Luck!