* Driving conditions: City driving will result in significantly lower average speeds than highway driving. Traffic, terrain (hills, mountains), and weather all play a role.
* Driving style: Aggressive acceleration and high speeds will lower fuel economy and thus the average speed for a given distance. Conversely, conservative driving will increase it.
* Vehicle condition: A well-maintained truck will likely perform better than one needing repairs.
* Towing: Towing a heavy load dramatically reduces average speed.
While you might see higher speeds *at times* on the highway, a reasonable *average* speed for a mix of city and highway driving might fall in the 40-55 mph range. However, this is a rough estimate, and your actual average speed could be considerably higher or lower depending on the factors listed above.
