Hi. New here. I was wondering what I should do. I have a 2000 Jeep Cherokee. My owners manual tells me to use Mopar Gear Oil or an equivalent 75W-90 GL5 or Synthetic 75W-140 if I tow or offroad. I was wondering if I could get by with a full synthetic blend of 75W-90. I don't tow but i do occasionally offroad my stock Jeep. Because I offroad occasionally I am wondering if I should put the 75W-140? The only available 75W-140 I have found has been Quaker States. It is $20.00 a liter. The mopar stuff is $27.00 a liter. Is the Quaker State stuff good? If I go with the synthetic 75W-90 I was planning on Castrol Syntec. What do you guys think I should do? Another question. If I put the 75W-140 in, will my gas mileage be affected? Thanks!
75W-90 or 75W-140?
- Thread starter Slippy345
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JHZR2
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I went from 90 to 140 in my BMW hoping to quiet a bit of diff whine. No changes in MPG were noted, though in reality there may be a 0.1 or 0.2 MPG change overall downward that just doesnt statistically register with me.
If you occasionally do light offroading, the 90 will be fine. If youre doing a lot of wheel spinning, rock crawling, high torque, low speeed type stuff while offroading, then you might want to consider the 140. Doesnt sound like it would be worth it for you though.
Redline's 90 weight gear oils claim to have very good film strength/thickness, and might compare with, say a 14w dino lube.
Redline, Specialty formulations and Mobil1 all look like good gear oils. Ive been happy with M1 and redline, havent tried SF. Ive heard excellent things about amsoil gear lubes, but have never actually tried them. Mail order might be a good choice so you can get some top notch stuff.
JMH
If you occasionally do light offroading, the 90 will be fine. If youre doing a lot of wheel spinning, rock crawling, high torque, low speeed type stuff while offroading, then you might want to consider the 140. Doesnt sound like it would be worth it for you though.
Redline's 90 weight gear oils claim to have very good film strength/thickness, and might compare with, say a 14w dino lube.
Redline, Specialty formulations and Mobil1 all look like good gear oils. Ive been happy with M1 and redline, havent tried SF. Ive heard excellent things about amsoil gear lubes, but have never actually tried them. Mail order might be a good choice so you can get some top notch stuff.
JMH
The limited slip would not work properly in our Isuzu Trooper with M1 75w-90 even with lots of LS additive - still got chatter on turns when hot. All is well with Valvoline 85w-140 synthetic, which was easier to find than Mobil 1.
In most rear axles the axle oil is lubricating not just the diff, but also the rear wheel bearings, so keep an eye on it.
In most rear axles the axle oil is lubricating not just the diff, but also the rear wheel bearings, so keep an eye on it.
MolaKule
Staff member
Slippy,
If you decide to use a synthetic 75W140, try our HDS-5 in 75W140, GL5 and MT-1.
Have you and a friend order a box of stuff and we will discount it.
If you decide to use a synthetic 75W140, try our HDS-5 in 75W140, GL5 and MT-1.
Have you and a friend order a box of stuff and we will discount it.
I've always run M1 75W-90 Syn in my TJ's D35. I offroad hard.
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