What engine oil

[HunterK]

Hey guys, I got a question. the guy I bought my mj from told me to only use amsoil 10w30 because that's all he's ever put in it. That stuff is so expensive and hard to find in jersey I don't want to keep changing the oil with amsoil. Should I continue using synthetic? Or does it really matter what oil I put in it? What oil are you guys running? Thanks.

[HunterK]

Hey guys, I got a question. the guy I bought my mj from told me to only use amsoil 10w30 because that's all he's ever put in it. That stuff is so expensive and hard to find in jersey I don't want to keep changing the oil with amsoil. Should I continue using synthetic? Or does it really matter what oil I put in it? What oil are you guys running? Thanks. It's the renix 4.0 by the way

[buckwheat]

Just a tip for ya: When I try searching for something I use Google. Except I only include comancheclub.com sites. So I found the following links by searching "site:comancheclub.com what oil to use". Remember that trick for future research. In the mean time, read these articles:

 

http://comancheclub.com/topic/36262-preferred-oil-weight/

http://comancheclub.com/topic/18739-oil/

http://comancheclub.com/topic/27580-best-motor-oil/

 

That should take care of your questions.

[Eagle]

If he has been using synthetic, I would continue to use synthetic. Keep in mind that with synthetic you can do longer oil change intervals. When my '88 Cherokee weas new, I changed the oil at 2,000 miles using conventional. My brother was service manager at a BMW dealership, and he told me that the BMWs were running full synthetic and that the factory recommended oil change interval was 15,000 miles. I figured I could certainly go 5,000 if they were going 15,000, so I switched. That was probably twenty years ago.

 

At first I used Mobil-1, then I changed to Castrol Syntec.

[xjrev10]

Rotella 5-40 with a wix filter.

(Blue bottle)

[Marine1Texas]

I change oil 2 times a year and I use synthetic. I use 5w50 mobile 1 synthetic in all 5 of my trucks and can go 15k between changes, but I change all in Nov and in April no matter the miles. I have not used any other oil for 20 years.

 

In Jersey you should use low weight of 5 in the winter at least. If your over 100k use 40 weight at least since it helps with aging motor parts. I don't think you need 50 weight on high side since it does not get to hot in jersey. So would recommend 5w40 winter 10w40 summer. but 10w30 is a little better in mpg in summer.

[Minuit]

My 91 loves Rotella T6 5W-40 with a wix or Mopar filter.

[cruiser54]

Yep^^yep^^^

[gogmorgo]

Don't know why you guys are running 5w40 so far south... The last couple years I've been running synthetic 5w40 in the winter and conventional 15w40 in the summer. Diesel oil, whatever's on sale. Although those of you still running cats, the higher zinc content of diesel oils isn't good for them in the long term.

[johnj92131]

"Synthetic" oils tend to last longer in more extreme conditions than "conventional" oils.  Question is:  Do you operate in extreme conditions?  Frankly, I don't think so.  Use a full synthetic if you want to.  Or use a good conventional oil like Shell Rotella.  Change it every 5000 miles or so.  

 

Personally, I have never liked the Amsol Marketing hype.  Way too much fear mongering and a way too expensive product for me.  I do not know of a single O.E.M. that says use only Amsol products.  The large auto makers all do WAY more testing than Amsol can possibly do.  Just take a look at the oil requirements from the large German car makers.  They have no problem making specific specification requirements for certain of their engines.  None of them spec Amsol.  AND Amsol does not meet their requirements.

 

Who knows more about engines:  BMW, etc or Amsol?   Honda or Amsol?

[HunterK]

I change oil 2 times a year and I use synthetic. I use 5w50 mobile 1 synthetic in all 5 of my trucks and can go 15k between changes, but I change all in Nov and in April no matter the miles. I have not used any other oil for 20 years.

 

In Jersey you should use low weight of 5 in the winter at least. If your over 100k use 40 weight at least since it helps with aging motor parts. I don't think you need 50 weight on high side since it does not get to hot in jersey. So would recommend 5w40 winter 10w40 summer. but 10w30 is a little better in mpg in summer.

. Engines almost at 250k haha thanks for the recommendations everyone

[gogmorgo]

With that kind of mileage you'll probably want to switch to a higher weight oil than a 10w30. I'm not hugely familiar with Jersey's climate, but I'm not quite convinced it gets cold enough for you to need to run a 5W but you never know. So like, 10w40. But ymmv.

This just came out. It's a bit interesting, and illustrates why I choose to run synthetic in the winter. The test/demonstration at the end could be a little misleading, especially since there's no mention of how much use either of the oils got, and also they do compare different weights of oils in stead of direct comparison between synthetic and conventional.

[Minuit]

Don't know why you guys are running 5w40 so far south... The last couple years I've been running synthetic 5w40 in the winter and conventional 15w40 in the summer. Diesel oil, whatever's on sale. Although those of you still running cats, the higher zinc content of diesel oils isn't good for them in the long term.

 

I run 5w40 because that's what my engine likes best in my approximation. I will freely admit I have no studies whatsoever to back my opinion up. Yes, I know about the temperature-oil viscosity chart. It seems to build oil pressure a little quicker on a cold start and maintain it a little better once warm with the Rotella vs the Pennzoil 10w30 I was running before. Sounds better too.

 

Regarding the zinc, not really in the case of T6. It has almost exactly the same ZDDP content (~1250ppm) as oils of the late 80s and early 90s so it's at most as bad for the cat as oils that were around when our trucks were made. Modern oils top out at about 800ppm. Even if it did make much of a difference to catalyst life I would rather preserve the flat tappet camshaft than the easily and relatively cheaply replaceable cat. When the oil pan was off, I noticed the cam lobes didn't really look all that pretty, so I figure the cam could use all the protection it can get. Does it make a big difference? Maybe not. I'm not an engine builder or a scientist, but almost all of my research tells me it does make at least a little bit of difference.

 

The 89? Gets the cheapest 10w30 I can find. With an engine that makes single digit warm idling oil pressure, I'm not going to fork out extra for fancy oil that's just gonna drip out onto the ground. As soon as I get the time and money it's gonna get an early HO long block anyway.

[gogmorgo]

Yeah, it's not a super huge effect, given how little engine oil actually makes it's way into the exhaust on a good-running engine, but it is part of the reason most motor oils have moved to reduced zddp.

[mikekaz1]

I like 10w40 in all 3 of my current 4.0s. And rotella honestly seems to hold up better then others at that.

[mvusse]

I use Mobil 1 high mileage 10w30. It is rated API SL and still has at least some zddp in it.

[Double Six]

I talked with a  NASCAR oil analyst and he said of all the oils they had tested shell rotella T 15w-40 held up better than any of them including racing oil. That's what i've always used in my 18 wheelers,since then I started using in my autos as well and have had no problems whatsoever.

[cruiser54]

I talked with a  NASCAR oil analyst and he said of all the oils they had tested shell rotella T 15w-40 held up better than any of them including racing oil. That's what i've always used in my 18 wheelers,since then I started using in my autos as well and have had no problems whatsoever.

Used it in my fleet of trucks also. Still use it in all my stuff to this day. 

[75sv1]

^{I used to use shell Rotella 15-45, then 10W-30. Both worked good, with a NAPA Gold filter. Same as a WIX. I now use the T6 Rotella 5-40, with a NAPA Platinum. I'd run synthetics 8K to 10K or for a year. I wouldn't worry about the temps. I have switched in other vehicles between conventional and synthetics and different brands on synthetics with no seen effects. Some like the European formula Castrol Syntech. I have not tried it. Autozone sells it.}

[Megadan]

Another vote for the Shell Rotella T6 5w-40 with a small bottle of STP oil treatment (Less than $3 and has ZPPD additive)  It's all I have used on my truck after trying a couple of others. Runs the best, lasts the longest.  I still do 3000-3500 intervals, but that's because my rings are a little worn and my oil will start to get a strong fuel smell to it around that time.

[75sv1]

IP89 brings up a good point. OCI is dependent also on the condition of the engine. I have run 12K + on a Ford Contour with the 2.0 ZETEC. That engine didn't use a drop of oil at 200K+ miles. I was mainly doing 8K OCI on it from about 20K on the Odo when I got it. I ran synthetics  all or almost all that time. Also, a few different brands, Castrol Syntec (not the Euro), Shaffer for a change, Mobil 1 for a change and Pennsoil Platinum. I ran to thick of Mobil 1 for that engine.

  I'll have to see about the STP for the ZPPD.