31" tires and gear ratio

[TheGringo]

Hey guys. I have a 2005 ford ranger edge with the 3.0 in it and wanted to jump up to 31" tires. I do 50/50 street and off road (dirt) and wanted to put bfg R/T tires on the truck. The stock ratio is the 4.10 so I was wondering if that would be fine for putting on 31x10.50x15? How would that hold up and would there be a major power difference? I'm not concerned about gas mileage, I just don't want to lose very much power. Anything helps!

 

[Curious Hound]

I find this chart handy.
http://www.therangerstation.com/tech_library/gearandtirechart.shtml

There are some other good tire/gear ratio/wheel size articles in the tech library. Check them out.

 

[gw33gp]

The 4.10 gears are in general good with 31" tires. The 3.0 engine is not great on torque so it would probably benefit with lower gears. If you have 2WD there may be 4.33 gears available depending on which rear axle you have. If you have 4WD, 4.56 gears would be the next lower gear. The 3.0 pretty much like high revs, so you should be OK there. I have 4.56 gears on my 4.0 SOHC Ranger and run 31" tires on pavement. At first I didn't like the higher rpm at the highway speeds I normally run but got used to it and really like how well it accelerates.

I you are running shorter tires and switch to taller tires you will notice slower acceleration if you keep the same gears. Many people don't mind that but you may. The best approach to it is, if you want 31" tires, go ahead a put them on. If you don't like how it accelerates or climbs hills, you will then need to invest in lower gears.

I can assure you 4.10 gears will work with 31" tires. I drove an 89 STX with a 2.9L engine for many years with 4.10 gears and 31" tires. I was very happy with it. Before I switched to the 4.10 gears it had 3.73 gears. That was not a good ratio for 31" tires. I burned out the clutch in about 50K miles.