oils ain't oils

[MDK]

A what's everyone using for your oils? Imo 5 30 is too light for the 3.8. Might be OK for emissions and snowy country but not qld, even in winter.

My new to me jku is due for a service in a few k and with 130 in it and having only had it for a few months I'll do them all so interested in the lot of them and also filters. Are jeep genuine the way to go there or are aftermarket worth a look. If so which ones are good which are bad?

Any tricks or surprises I should be aware of to do the job?

[wrench]

I use 5w30 full synthetic on all our motors bar the old clunkers. If that worries you then use a 5w40.
Remember low viscosity synthetic oils protect far better than thicker mineral oils due to lots if improvements including longer molecular structure.

Most quality aftermarket filters work as well or better than OEM.

Edit: After years of believing we needed thicker oils in QLD I was set straught by an oil company tech adviser about 15 years ago. Even in our ambient temperature your motor still runs at approx 100 deg celcius the same as in snow country. This is controlled by the cooling system which warms the motor to that temp as soon as possible and then holds it there. Some exemptions such ad using oil coolers etc exist but in most cases the oil film strength is more important than the viscosity.

[SeaComms]

I use Nulon full synthetic 5w30 (about $50 for 6 litres on special at Supercheap), and use a Ryco z37 filter from memory. Almost double the size of the oem filter.

One trap - as the drain is on tje rear or the sump and not the bottom, when first undone the oil will shoot out quite a way and potentially past your drain tub....

Sent from a tiny keyboard with fat fingers, apologies for my spelling. .

[MightyMouse]

The use of these super thin oils is also about the US based "Corporate Average Fuel Economy ( CAFE - pronounce with a K ) )" legislation. Vehicle manufactures will sell their souls to gain another 0.1 ltrs/100 km, regardless of the consequences to your engine.

For them CAFE is serious stuff and can put them out of business, so long term engine protection isn't their major concern.

Also the 3.8 isn't a highly stressed engine, IMO regular oil changes with good quality oil is far more important than blowing heaps of cash on premium oil. If you want to pamper your engine change the oil more frequently.

The days of needing 20W50 minimum are over as oils have come a long way... but my choice is 10W... I'll sacrifice a possible tiny economy hit ( its a JK ffs... ) for superior protection when the engine is really working hard off road.

[layback40]

I use 5w30 full synthetic on all our motors bar the old clunkers. If that worries you then use a 5w40.
Remember low viscosity synthetic oils protect far better than thicker mineral oils due to lots if improvements including longer molecular structure.

Most quality aftermarket filters work as well or better than OEM.

Edit: After years of believing we needed thicker oils in QLD I was set straught by an oil company tech adviser about 15 years ago. Even in our ambient temperature your motor still runs at approx 100 deg celcius the same as in snow country. This is controlled by the cooling system which warms the motor to that temp as soon as possible and then holds it there. Some exemptions such ad using oil coolers etc exist but in most cases the oil film strength is more important than the viscosity.

Most engine wear occurs in the first moments after the engine starts. need thin oil then to get it to the bearings etc quick.
Oil runs much hotter in hot conditions. i know this from work with earth moving gear that has oil temp gauges. Best get your oil tech to talk to a few engine manufacturer techs. Sounds like he is reading too many books.
Do you have any data on "oil film strength"? You may find "oil film strength" is a function of viscosity.

[Rodent]

My dealer used 10w30 on my first service (3.6lt) - anyone else using this?

Local mechanic has used 5w30 on the second service, noticing a bit more noise on cold start up.

[milky01]

My first oil change in a 2013 JKU used Nulon 5w20 per Chrysler spec. Interesting that the 2012 models recommend 5w30. There are rumours that CAFE is the reasoning, but others say that 5w20 helps with the VVT valvetrain so who knows what their reasoning is for the change (maybe both?). As others have said I think using a good oil with quality additives changed diligently is the key. You can also get your oil samples sent off for analysis if you wanted to get really serious e.g. high silica levels could be from driving in sandy/dusty areas.

[Banshee]

I used 5w20 or 5w30 in my 3.8 as recommended to start with & was regularly at or below the add oil mark by the time the next service was due.

Switched to Penrite HPR Diesel 5 (5W40 and the same oil I run in my CBR1100XX). Doesn't use anywhere near as much now. I also use the z37 filters.