I drive mainly on the street with little to no towing. Some occasional off roading.

For street use they recommend 75w-90 in the rear diff and 75w-140 if towing/off-roading.

So what's the downside to using 75w-140 if your not towing/offroading? gas mileage?

_________________
2006 Jeep Liberty Sport 4x4 3.7

Yup, a slight mpg hit. No need to mess with the 75-140 for you I bet.

_________________
05 CRD: H.D.S2 stat,WW Ironrock trilink&LCA's, OX rear,ARB front, 4.10's, ARB bumper, Suncoast,OME 3.5, JBA UCA,rock rails, Moabs&265/75 Duratracs, GDE tunes ,FFD fan,ARP's, 2 micron fuel, new valves,sasquatch battery tray & grid heater, tensioner relocated
Mech fan, VH & AC delete

Ran it in my 04 for the last 2000,000 miles, and swapped over the 03 when I bought it a few months back

_________________
MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

I'm hoping it will stop my minor pinion leak until I can afford my Ox locker. Before I knew any better, I put synthetic in, and sure enough, it leaks. Fingers crossed it will hold out for 6-12 months with thicker dyno...

_________________
05 CRD: H.D.S2 stat,WW Ironrock trilink&LCA's, OX rear,ARB front, 4.10's, ARB bumper, Suncoast,OME 3.5, JBA UCA,rock rails, Moabs&265/75 Duratracs, GDE tunes ,FFD fan,ARP's, 2 micron fuel, new valves,sasquatch battery tray & grid heater, tensioner relocated
Mech fan, VH & AC delete