Ford 2010 F-250 Owner's Manual page 23

Instrument Cluster
Tachometer: Indicates the engine speed in revolutions per minute.
Driving with your tachometer pointer continuously at the top of the scale
may damage the engine.
Standard instrument cluster
Harley-Davidson instrument
cluster
Engine oil pressure gauge:
Indicates engine oil pressure. The
needle should stay in the normal
operating range (between "L" and
"H"). If the needle falls below the
normal range, stop the vehicle, turn
off the engine and check the engine
oil level. Add oil if needed. If the oil
level is correct, have your vehicle checked at your authorized dealer.
23
2010 F-250/350/450/550 (f23)
Owners Guide, 1st Printing
USA (fus)