2002 chev. 1500 fuel milage

Over the life of my 2002 ext cab with a 5.3 auto has been 16.45. I use excel to keep track. All my driving is in city. Two trips on highway were

You do not mention what tire size and type you have which can be a BOG factor in MPG as well as the way you drive and the terrain you drive in. BTW, if you read the actual EPA test cycle for highway MPG, they never exceed 60 and the average speed for the 12 minute test is 48MPH. Nobody averages 48 on highway except maybe in a city at rush hour (if that) but it is how they weight the test to their favor for marketing. If they used a higher more realistic standard, the "ratings" would be lower. Newer test standards are in the works and while some claim could MPG with those trucks, you have a lot of weight/mass there and it take fuel to move it.

I get the EPA estimates with my 04 driving at 65mph so why can't an 02?

No two drivers are the same and the mud grips and tha average temp of

It could be normal. What you don't say is:

-has the mileage always been like this or is it slowly getting worse? (need a tuneup)

-your average highway speed is 85 mph. (probably normal fuel economy at that speed.)

-uphill in the mountains towing a boat (you're getting good fuel economy.)

Ray