Gearing formula question

BDAB · 09-01-2007, 08:18 PM

this is for you math wizzes. my tire size is 295/75/22.5 (39.4"). I am turning 1700 rpms @ 55 mph in what should be my direct drive gear. what are my gear ratios?

martin · 09-01-2007, 08:25 PM

would you verify that tyre size again as it works out to fourty inches, also 1700 rpm at what speed?

BDAB · 09-01-2007, 08:28 PM

I edited, I checked it with the tire size calulator, I got 39.4"...... 55mph ..... this is for my new freightliner.... no axle tag and i need to know the gear ratio.

Hahnsb2 · 09-01-2007, 08:57 PM

3.55ish, it would be a bit more accurate if you measure the tires with a tape, they usually never measure out to what they're supposed to...

BDAB · 09-01-2007, 09:03 PM

ok thanks, that would be 3.58's (common in a freightliner).

09-01-2007, 08:25 PM	#2
martin Member Join Date: Aug 2007 Location: St Bruno, Quebec Year: 1984 1991 Make: ford Model: b2 explorer Posts: 2,778 Rep Power: 20 iTrader: (0)	would you verify that tyre size again as it works out to fourty inches, also 1700 rpm at what speed?
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09-01-2007, 08:57 PM	#4
Hahnsb2 Member Join Date: Aug 2007 Location: Battle Ground WA Year: 88-95 Make: Ford-Dodge Model: BII-Dakota Engine: 4.0-5.2 Turbo Class: Real 4WD, 3WD. Used For: Going where I point it-Going fast Posts: 4,408 Rep Power: 24 iTrader: (1)	3.55ish, it would be a bit more accurate if you measure the tires with a tape, they usually never measure out to what they're supposed to... __________________ 88 Bronco II, 4.0L, M5OD, 4.56s, Aussie Locked 8.8/D35, 1354M, 34" LTBs 95 Dakota CC, 5.2, 5 Spd, 2WD,Turbo, Megasquirt, 3.55s, Locked
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