snakeyes76

been running 10w30 for a few months now. haven't checked the dipstick yet but i only used to burn 1 quart every 6000 miles. is a little smoother however

DeucesALLin

I think I am gonna do it...

chaz14_9

I live in Texas so I put 10w30 in and I love the difference it made

DeucesALLin

I agree completely.

spartan99

I have the exact same oil consumption issues expressed on this thread. About a quart every couple thousand miles or so. I have almost 60k miles on it and drive like a grandma.

I am going to start adding 15 40 now when it runs low and see how things go.

Thanks for this thread it has been very informative.

azrwilkinson

I know my jeep pings so bad I let off the throttle a little, to me that is from too much heat, even though the temp gauge reads just under 1/2. Maybe this is what I need to do to eliminate this issue. Or the oil isn't holding up when at operating temperature and under load to keep lifters pumped up (are they Hydraulic lifters?)

Rubicon John

I drive 60+ miles on the highway each day and noticed that I was burning oil (~1000 miles I'd lose a quart) with the 5w20, made the switch to 10w30 and the oil burning has stopped!

The jeep is running better than ever and I did note a slight increase in MPG.

Flip94ta

I just want to add some basics here. If your crankcase vent(PVC) is moving lots of oil your rings could be worn, or your oil is so thin it's bypassing the oil control ring.

The first number, 0, 5, 10,15 or 20 is the cold thickness of the oil. You really want the lowest number. The lower the number the faster the oil reaches the lifters and bearings during start up. Ironically you'll have a louder engine with a thinner weight on a cold engine, but it's lubed and if you don't beat on a cold engine your fine.

The upper number, 20, 30, 40 and 50 of course is the hot thickness. A 20 will make a louder(ticky) motor that has more power but it could suffer more wear as the light weight oil has a low shear tolerance. The heavier weight will sap power but run quieter and last longer. Just remember, the hotter it is outside or under your hood like while towing, the less protected you are. The thinner oil will turn into mist easer as mentioned, this sends oil into the PCV, which in turn is burned again in the combustion chamber. If enough oil is present detonation will occur and the ECM will pull timing/less power.

A couple of years ago oil switched to low/no phosphorus and zinc. Older engines need those to resist wear. The Ph and Zi was especially important to flat tappet engines like the 4.0L. The 3.8L is a roller cam but it's possible the rings aren't new oil friendly. I believe the change occurred during the API change to SM from SL. On the other hand most diesels on the road are flat tappet. Diesel oil still has the Ph and Zi content to protect your engine. Also speed shops like summit racing will sell Ph/Zi additive bottles or "offroad" use oil in regular and synthetic.

It's also been proven many times that synthetic starts thinner and holds its thickness better when hot, even really hot compared to conventional.

I'd recommend 5w30 diesel synthetic or 5w40 which is easier to find in some places to any 3.8L owner, or royal purple 5w30 offroad which is what I use since summit is close.

backwoodjk

I decided to try Castrol GTX 10W-40 combined with a Purolator pure one filter. Results so far have been great, no start up rattle, no oil consumption, engine is quieter at idle.

TINMAN080

I've used Pennzoil 10W30 exclusively since 1988. Nothing else. Chevy's, Buicks, Oldsmobiles and Jeeps. NO issues, no clattering, no oil consumpsion at all. Well over a million miles total on these vehicles and NO issues. I've always used Fram base filters- No issues, no drainback, no clatter, no leakage. I've advised friends to drop their synthetic oils because of usage concerns and engine noise, and in every case real improvement has been noted. It's all in ''cling'' and film thickness of the oil being used. The synthetics are simply dyno oil manipulated to ensure same-sized molecules. Sounds good, but the thin film and low cling cause your little tics and startup noises and yes, oil usage. My '95 YJ, a 4 cylinder 5 speed had 198,000 on it when I sold it, no ticks, noises or oil usage. None. My '98 Olds had 162,000 when I sold it, no issues. My '01 Silverado had 125,000 and no issues. My '06 Impala has 130,000 now and no issues. None. I've used 10W30 in my JK (75,000) since almost new, no usage, no ticks. None. I change myself every 3000 or so. This is my real-world experience. Best of luck!