You would need to specify which transmission you have. On the older autoshifts with the clutch pedal, you could override the automatic function to get it to downshift manually, but you couldn't override it on the upshift. Some of the modern clutch free automatics have a feature which allows you to do this.
Yes
US Xpress, PAM Transport, Maverick.
Maverick, US Xpress, PAM Transport.
Usually, it won't go into gear. If you get it into gear, you could cause serious damage to the transmission.
18 wheeler has the higher gross weight
on average you need to fuel an 18 wheeler once a day
That depends on what your rear end gear ratios are. It varies greatly. As a default, you typically upshift at 1500 RPMs and downshift at 1000 RPMs.
18 wheeler
Ernie Wheeler died on 1982-06-18.
Earle Wheeler died on 1975-12-18.
Andrew Wheeler was born on 1988-01-18.
18 Wheeler - 1979 VG was released on: USA: July 1979