Welcome to the SR20 Community Forum - The Dash.
SR20 forum logo

Thread: Got rod knock? What oil were you using?

+ Reply To Thread
Posts: 21-30 of 114
2009-05-24 15:28:50
Originally Posted by Dudeman258
There is a problem here because most users here use Mobil One. Therefore the likely hood of getting rod knock will be grater then most other brands regardless of the cause.


Well said.
2009-05-24 21:10:28
Originally Posted by Dudeman258
There is a problem here because most users here use Mobil One. Therefore the likely hood of getting rod knock will be grater then most other brands regardless of the cause.


So everyone here must be completely ignorant to the wear results in the IVA test then?

I disagree with your assertion that Mobil 1 has always done well in UOA (user oil analysis), as bobistheoilguy.com forums has seen a lot of people complain about excessive iron (Fe) wear using Mobil 1 for a long time. At one point recently, I saw a list somebody had of about 100 or so UOA results showing the Fe wear figure, and Mobil 1 tended to have the worst wear of any of the oils there, including conventional oils on the list. (There are so many variables in any one UOA, but if you have a lot of them, across many cars, and you see Mobil 1 almost always having excessive wear, then that is probably a trend result.)



General UOAs for Mobil 1 come back with around 30-50ppm iron wear on mostly stock engines. Here is a Castrol 0w30 wear test after a lot of miles: Only 9ppm iron in 8000 miles of use!


I'm extremely impressed with my oil analysis results using German Castrol 0w30, so I'd have to recommend that one. In fact this oil has impressed the guy who interprets my oil analysis results and he is now running it in his vehicles too! He has been interpreting oil analysis results for almost 25 years now, so if he's impressed with an oil, that says a lot.

Now this could all just be a bunch of rubbish, or these guys who are dissappointed with their Mobil 1 wear results could be on to something?

If I ran ANY Mobil 1 it would be the high mileage 10w40. From what I understand it is still SL rated and is the old formula 15w50 racing oil.
2009-05-25 13:38:34
I always run castrol. One of my friends fathers is the quality control and oil testing person. Whatever he does hes been doing it for about 25yrs and hes very high up. He makes custom oils for all kinds of race cars and everything like that. I asked him about all the different types of oil and he very scientifically explained to me why castrol is the best. Its a long 30 min phone conversation but, I will always use castrol until I spin a bearing. I've been running it on my boosted sr daily for 3 years. I just switched to the new castrol edge and that has been great so far. I will let you all know the day castrol fails me. Even then it will probably be my extremely hard driving style that may do it also.
2009-05-25 20:44:11
i personally think mobil 1 is a little thin for older engines, it isnt really doing them any favors. I
2009-05-26 03:14:03
A ton of people are raving about the Castrol 0w30 german blend and the Edge. The Edge has a very stout additive package! The good stuff overseas is better though. 0w30 and 0w40 are supposedly good for 30K miles! :O
2009-05-26 09:17:07
Originally Posted by Coheed
A ton of people are raving about the Castrol 0w30 german blend and the Edge. The Edge has a very stout additive package! The good stuff overseas is better though. 0w30 and 0w40 are supposedly good for 30K miles! :O

yeah a few people have raved about the edge. I havent used it yet though. Wouldn't mind trying it out. In all honesty for your average de/ve set up i would probably run a shell helix semi syth over mobil one and change more often.
2009-05-26 21:44:43
What weight is recommended for boosted and track use then?

I use Pennzoil Platinum right now 5w 30 (no spun bearings tho).
2009-05-27 02:55:12
The pennzoil has a high shear strenght. Um I would go with a 5w40 or 15w40 to start. Only run the 50 in the summer time when it is 75*F+
2009-05-27 03:29:25
Originally Posted by Coheed
Rotella synth is has amazing bang for buck!

+1. Extensive UOA on our VQ35DE motors showed M1 was pretty good, but has shown some serious issues with shear and wear, not just a little, either.

This is prob a repost in part here, but good, good stuff here:

VQ Oil Analysis and Info - MY350Z.COM Forums

then check here for a few year's worth of results distilled down to oil good, oil not so good:
MY350Z.COM Forums - View Single Post - VQ Oil Analysis and Info

Red bad, green good. Guy who did the crunching does not have an interest in nor works for any of the companies producing the oils. Testing was done completely voluntary contribution of sample data over time by Z/G owners with all kinds of driving, climates, etc. the only constant being the general type of motor.

Bottom line:

Of all the M1 blends, M1 10W-30 has the least amount of PAO base stock, and is in my opinion, the worst formulation they sell. The issue lies in the fact that people still demand an antiquated grade of oil such as 10W-30. ...This is why I say the M1 0W-40, which costs the same as the 5W and 10W blends, is the best option for the money if you want to use M1 products.

The problem with current formulation of M1 10W-30 is it is a thin 30W to start with, and under extreme conditions (heat, etc.) seems to be prone to TBN breakdown - that's in short when your oil runs like water out of the motor.

On the VHR motors Nissan actually throttles back the revs when the oil becomes too thin. In other words it assumes from oil temp that the oil is becoming less viscous, and starts dialing back the revs you have on tap. These have a very complex valve and cam setup, but ironically the major problems have been bearing wear and in earlier motors, ring wear. If ring wear gets bad in a FI motor, then you potentially have gas in the oil thinning it further, and about 5 minutes more use of the motor.

...I'm not at all surprised the M1 10W-30 looks like complete ass in your engine. This oil had the bejeezus sheared out of it, and is nowhere near a 30 weight oil anymore. It's actually thinner than most 20 weight oils I've seen. This is a real issue for you, since an oil's ability to resist shear under extreme pressure is a function of its viscosity. This is why the new VHR engines reduce revs and power when the oil temperature becomes too high, since an oil becomes less viscous with heat.

These are def generalities when applied to SR20 motors, but the resistance to shear is where an oil and your motor lives or dies. TBN is one measure, and 10W-30 M1 is not a good choice for shear resistance under heavy use.

The fuel dilution isn't a good sign, either. Chances are, your rings are wearing and you've got fuel getting into the crankcase from excessive blow-by. The cheaper base stock used in the 10W-30 is not going to handle fuel (which is a solvent) very well. The fuel dilution only makes the oil shear issue worse.

Drive it the same with the Rotella in as you did during this sample, if you can. Change the T-Syn at 4500 miles and get a UOA. Let's see how much improvement we can get with just the oil. I predict a MUCH better UOA with the T-Syn.

I'm running the Rotella with 0W-40W, hard track use and heat, so far so good, it's my second change so this round I'm snagging a sample for Blackstone UOA. I'll have about 4000 miles and 3 full track days on the oil when I send it in. Edit: from my SR20, not my VQ.

If you don't test the used oil, then you really don't know until it's too late. Take a lot of test info combined with a little sound stats and math, and we already figured out that M1 wasn't the best solution for protecting the VQ35DE. I don't know anyone who has done anything close to Will's work for SR20's, but you can learn a lot from what he's done on another forum.
2009-05-27 03:41:14
Forgot to mention the downside: Rotella 0W-40W is a thicker hot oil than M1 10W-30, you will likely see lower mpg and maybe even slightly lower peak hp on a dyno, but that's not worth much to me if I toast my motor. I'm still running 25 mpg around town and close to 30 mpg hwy, only off about 2-3 mpg. Motor dyno'd out clean sustainable peak hp from about 6200 to 7500, 141 whp with basic bolt-ons, etc. Much more concerned about holding the motor together than whether I see 145 whp vs. 141 whp or 32 mpg vs. 28-30.

Running a little rich up top so the peak drops flat, but look how it holds from 6200 to 7200 - steady. Not big numbers by any means but this is motor with bone stock internals. For classing reasons I haven't put in cams (C2's in a box, kills me on track days) or any other mods inside the motor. So if Rotella T-syn is costing me any peak hp, which I doubt, I can live with it. More likely the half tank of race fuel in the car pooched the top end with slower complete burn of 100 octane race gas, not a good thing when it's tuned for 91 octane in the JWT ECU.
+ Reply To Thread
  • [Type to search users.]
  • Quick Reply
    Thread Information
    There are currently ? users browsing this thread. (? members & ? guests)

    Back to top