Found on Cummins diesel site.....

cdlaine wrote:
Team...

Just starting to build my own "+/-" database/spreadsheet info
on the Big Three 1 ton HD Diesels.... pending purchase at some
point in the future....

as such, stumbled across this little MPG factoid sheet, and
thought it had some data points worthy of sharing...

enjoy... your mileage may vary.

Charles

from Cummins..... wrote:
Rock-Solid Rules


Every 2% reduction in aerodynamic drag results in approximately 1% improvement in fuel economy

Above 55 mph, each 1 mph increase in vehicle speed decreases fuel economy by 0.1 mpg.

Worn tires provide better fuel economy than new tires, up to 7% better fuel economy.

Used lug drive tires can get up to 0.4 mpg better than new lug tires.

Ribbed tires on the drive axles provide 2–4% better fuel economy than lugged tires.

Every 10 psi that a truck’s tires are underinflated reduces fuel economy by 1%.

The break-in period for tires is between 35,000 and 50,000 miles.

Tires make biggest difference in mpg below around 50 mph; aerodynamics is the most important factor over around 50 mph.

The most efficient drivers get about 30% better fuel economy than the least efficient drivers.

Idle time is costly. Every hour of idle time in a long-haul operation can decrease fuel efficiency by 1%.

Cummins website.....