I have been using 20/50 castrol for as long as i can remember from toy p-up,Tj Xj,ZJ 5.9 and all run great and when ever i open one up for one reason or the other i have no sludge. and i change at every 3k and the toy has over 300k on it, Tj 210k and the Xj 197km Zj has 156k. Oh and i use the K&n filters. This weight may to much for some but with our heat and i run them hard and it works for me.

 

I believe manufacturer recommendations are based on 1) the worst case scenario with the crappiest oil they could imagine, 2) the general belief that if they say to change the oil every xxxx miles, the average driver will go well beyond that before getting it changed, and 3) the fact that they can make more money off the buyer with shorter OCIs since when you buy a new car you'll most likely use the dealership for a while for maintenance.

They are of course based on engine design tolerances as well (my Acura TL-s has a recommended OCI of 7500miles for example)

Although the perfect OCI does vary a bit depending on engine design, age and usage, it's mostly dependent on the oil that you use, or rather the additive package that the oil manufacturer uses. Quite a few people have turned to getting used oil analysis done to hone in on exactly what interval they should use. While these results vary, every test I've seen done shows the oil has barely even started breaking down at 3000 miles, and is fully useful well into the 5000-6000 range and above (i've seen as high as 12k before). Consumer Reports did an extremely extensive OCI test in the mid 2000s as well with bunch NYC taxi cabs in an environment/service condition that most engines wont even get remotely close to, and found 6000mile OCIs to be more than adequate.

Filter changes are more important though, as most filters will only last about 5-7000 miles before it's full and transfers to bypass mode, at which point it's no longer cleaning the oil.

It's certainly your choice to change it at 3k miles, but the hard facts say it's not necessary with modern oils. Just my $0.02 - take it or leave it. If you really want to see what your engine/oil combination is good for, get testing done (www.blackstone-labs.com)

 

For $12 do they include new oil? I would be quite paranoid going to anyone that cheap. If it is new oil, what is it!?

 

Never mix oil. Yes anything will work, but it's not designed to mix with a completely different formula. Know ones a chemist here. You don't want sludge. Never put additives, they burn first. Never use fram oil filters. imo

 

It is new oil but thats just it, you don't know what it is

 

My owners manual gives OCI's and they vary quite a bit depending on driving style, temps, etc. Ive been using Gastrol GTX with Puolator, Mobile 1, K&N or Wix filter (whatever my local Car Quest has in stock at the time) and I go up to 9K on changes (yeah, I know, but my driving isnt hard core). I usually change it from 5K to 7K and Ive never had oil look remotely bad. I just picked up some Mobile 1 full synthetic and Im switching full time to it. Im using a Wix filter (never this combo before) but I havent heard anything bad. Cant wait to see the results.

 

Um, the current API service level for Gasoline Passenger cars and light trucks is SN. Deals with Higher temps better, has more MolybedenumDisulfide for increased fuel economy, more Shear resistant, blahblahblah. I wouldnt be using a 5w-30 weight any way in this heat this summer. 10w-30 would be the thinnest I would use for a 4.0. I love the HeavyDuty performance of Shell Rotella T5 10w-30. The perfect Motor oil for most any Jeep 2.5 or 4.0 most anywhere in the world. Well most people in the rest of the world would probably use a 40 weight oil of some kind. 0w-40 or 5w-40 in Europe most likely, 10w-40 or 15w-40 or 40HD in Australia. No, they use crazy weights like 25w-70!

 

You do realize that 5w-30 and 10w-30 are EXACTLY the same at operating temperature right?

 

Oil, ... schmoil.

Just change your oil (whatever it is) frequently and use the money you saved by not wasting it on "snake oil" to buy better beer (Samuel Adams summer ale would be my recommendation).

 

Heh Mudrunner, why are you taking a wizz on your rig in your avatar (whatever the *ell that little pic is called)??

 

I run Valvoline Syntec Full Synthetic 10w30 and a K&N oil filter. I change my oil every 6,000 miles/ 6 months. It saves money in the long run and i've been doing it for a long time with good results.

Since I just rolled over 79,000 miles in the 96, I will be switching over to valvoline high mileage full synthetic 10w30 with my next oil change because it has a lot more detergent to clean out your engine in it.

Good luck finding your leak, my jeep used to leak too and last oil change, I figured out that it was because of a bad seal on the drain plug! Hahaha

 

Yikes.

Bobistheoilguy.com

I use grapeseed oil and old hotdog buns for filters.

Read the info from the un-sponsored website I listed above. You will learn about oil weights and what they REALLY do for you.

(I use Mobil 1 5w-30 and pureone purolator filters)
My Suburban has 249,000 and has been mobil 1 the whole way.

I suggest finding actual research and studies performed by people other than amsoil, royal purple, Mobil 1, etc. etc.....

And asking us about oil is not a good idea either. Our history with oil is anecdotal at best. People thought leeches removed bad blood from sick people at one point. Not much different with oil and filter theories in here.

 

Let me wiegh in on this subject a little. I run my own shop, have been a technician for 16 yrs now, am an ASE Cert Master Auto/ Diesel tech with My L1/ L2, Ford Master Tech.
On that note, I have been using a non name brand oil for my customers since I opened, it's the only way I can make a profit on an oil change, point blank, unless the customer is willing to pay $50 for a regular oil change. I charge $35 for a oil filter that meets and exceeds all industry standards that is non name brand (Prime). I also use 3 different oils which are made in the same plant, same additives and all, different names, depeding on what my supplier can get cheaper that purchase.
I have 5 fleets of trucks, mostly rangers with 3.0's and 4.0's. None of the companies will change the oil any less than 6K miles, and when I first opened I though goodie, engine jobs to come, but, not yet. I, one day for my own curiosity, took a sample of one of the trucks oil and sent it off, to find that the oil still had some life left.
After 250K on the clock of a few of these trucks, the exhaust vavle seats were sinking into the heads of these 3.0's and causing missfires. So pulling the heads off I was extremely suprised to find the upper end extremely clean, and cross hatches in the cylinders.
On one other thruck the oil pan was leaking, and came in for repair, I pulled the engine out, and found the bottom end of this one looked brand new after 300K and still had cross hatches in the cylinders.
I can honestly say now, knowing what I have seen, as long as the oil you are using has the API's current certification, and you use the correct wieght oil, and use a decent filter, you will more than likely not have problems if you actually change your oil on a set interval, and check it periodically with UOA's.

Sorry for the length, but hey this is what I have seen, oh BTW, My 3 oils are Accel , Sure Gaurd, and Super S

 

Not ment to bash you in any way - Just using you as an example

Non-Name Brand Oil w/$35 oil filter - only way to make a profit
This is the reason I do my own oil changes - I may spend $35 Total to do a oil change & I know what Im getting

Agreed - regular interval oil changes keep problems from happening - period.

What it all boils down to is: Oil Changes is just a matter of personal preference on the oil & filter.

Mine just happens to be stuff that is "known" to be better for flat tappet jeep engines. Which doesnt cost (that much) more than the regular stuff. Figured might as well at that point, give it a try.
And after burying one that had 400K+ miles on it - with using this stuff - might as well keep going with it until I lose faith in it or find something better Im willing to risk my baby's life with.

 

To be honest oil changes are kind of an aggrevation for aq shop like me, I do it only for my regulars convienence, I wish I could tell them go to super lube, but know that they would screw something up and try to sell them something they dont need.

I know your not bashing, but when you buy name brand like that you have to pay for it. Think of it this way my shop's cost on a 5 qt oil change is roughly $12, now I have to write a check for my supplier for this oil, I have to also store and catalog this oil and filter, I have to pay for the electricity, phone, lights, rent, insurance, etc, pay myself, pay a counter person to handle the sale, have office equipment, and software to do the sale/ keep track of sales, and a book keeper to keep me right on my taxes and all, so $35 for an oil change is barely breaking even when you consider it. Which is why I have to use something I know will take care of my customers engine's, transmissions, diff's, but still keep me in a decent retail price. Just saying is all.....