Synth 40 weights

[aquariuscsm]

Compare,contrast,and discuss these synthetic 40 weights. Tell me your experiences with these,which you feel is best,and which you`d recommend and why.

Castrol Syntec 10W40
Rotella T6 5W40
Valvoline Synpower MST 5W40

 

[tenderloin]

Valvolune 5W40 MST Ran about 6 OCI's in daughters New Beetle......Have it in there now. Quiet, good throttle response and mileage. Recommended

 

[Quattro Pete]

Originally Posted By: aquariuscsm
which you feel is best,

Best for what? What's the application and what are you trying to accomplish or what problem are you trying to solve?

Out of the three, I've personally used T6 in the past. It was the only one of the three that carried JASO MA spec which my shared sump bike needed, so it was "best" in that respect. I also ran it in our old Jetta 2.0 for 10K miles and it did fine, alas, that engine consumed quite a bit of oil, so there was quite a bit of top up along the way.

 

[Garak]

Originally Posted By: Quattro Pete
Best for what? What's the application and what are you trying to accomplish or what problem are you trying to solve?

Yep, they're not all quite interchangeable. Plus, he left some good ones out. What about RP 5w-40? I think that one might still have Synerlec.

And we all know how I feel about Delvac 1.

 

[Clevy]

Originally Posted By: Garak
Originally Posted By: Quattro Pete
Best for what? What's the application and what are you trying to accomplish or what problem are you trying to solve?

Yep, they're not all quite interchangeable. Plus, he left some good ones out. What about RP 5w-40? I think that one might still have Synerlec.

And we all know how I feel about Delvac 1.


I've got a pile of misc RP in the garage and the only ones badged with synerlec are the euro spec 5w30 and 5w-40. They might still have it in some other lines however I haven't seen any for quite some time now.

 

[aquariuscsm]

I`m just wanting to compare the *cheap* Walmart 40 weight synths for my car. I`ve read alot of raves about T6 and have thought about trying it. How different is it from the other two I mentioned? From VOA,I see it has more moly and zddp.

 

[147_Grain]

Other synthetic blends to consider are Mobil's 0W-40 which has a stronger total additive package. I consider this oil to be the leader of the 40-weight pack and an excellent value for the dollar.

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1722539


Rotella T-6 is a good product too, but the TBN is average at 9.9 versus 12.5 for the 0W-40.

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2330040


Viscosity range of both products are similar, with the 0W-40 outperforming the 5W-40 by 20*F. in the Flashpoint test and the T-6 having more zinc.

Many BITOG's are blending the Mobil 1 0W-40 with a thin lightweight oil (i.e. 0W-20 or 5W-20) to come up with a oil that's 10% thinner at startup and has a 10% stronger film strength (HTSH) at high temperatures.

 

[KCJeep]

If you want cheap Wally's has started carrying the Delo 5w40 in the last year or so, for a couple bucks less a jug than the T6 too. I would think it at least the equal of T6 if not better.

 

[Quattro Pete]

Originally Posted By: 147_Grain
Other synthetic blends to consider are Mobil's 0W-40 which has a stronger total additive package. I consider this oil to be the leader of the 40-weight pack and an excellent value for the dollar.

I would agree. It meets some of the most stringent mfg specs, yet costs no more than Rotella T6 at walmart. Actually, I think Mobil 1 0w-40 in 5.1qt containers costs less than rotella on a per quart basis.

 

[Norm Olt]

Originally Posted By: 147_Grain

Rotella T-6 is a good product too, but the TBN is average at 9.9 versus 12.5 for the 0W-40.


Does the starting TBN figure really make any difference vs. what it is at the end of the OCI? Especially if we are not talking about an extended interval?

In otherwords, for say a 7,500 mile OCI, what's the diff?

Cheers!

p.s. re: the original post, whatever's the lea$t expen$ive, IMHO. They are all good!

 

[Quattro Pete]

Originally Posted By: Norm Olt
Especially if we are not talking about an extended interval?

And that's why I tried to get more info out of OP to elaborate on his particular application. If he's not going to be doing extended OCIs, then maybe even mineral oil would work for him, and it would be less expensive still. Although, if his 300zx is turbocharged (is it?), then he may want to stick with synthetics for that reason alone.

 

[aquariuscsm]

I'ts an n/a (normally aspirated non-turbo) and I never go over 3/3000. So yeah,conventional is probably the way to go. It was just some food for thought I guess.

 

[dailydriver]

You also have the BC (Belgique Castrol) 5W-40, albeit not on the shelves at Sino-Mart, nor as good as the Mobil 1 0W-40, overall.

 

[Quattro Pete]

Originally Posted By: dailydriver
You also have the BC (Belgique Castrol) 5W-40, albeit not on the shelves at Sino-Mart, nor as good as the Mobil 1 0W-40, overall.

Castrol 5w-40 is no longer made in Belgium. However, the new Castrol 0w-40 is.

 

[A_Harman]

Originally Posted By: aquariuscsm
Compare,contrast,and discuss these synthetic 40 weights. Tell me your experiences with these,which you feel is best,and which you`d recommend and why.

Castrol Syntec 10W40
Rotella T6 5W40
Valvoline Synpower MST 5W40


I've been running RT6 in my Cummins Dodge for almost 2 years now, and my first OCI was at 24k miles with about 25% usable TBN remaining when I drained it. I'm currently getting oil consumption of about 9k miles/qt. I'm very satisfied with it in my application.

On the other hand, I also think that RT6 is the most over-recommended oil on BITOG. People want to recommend it for gasoline applications, even though it is primarily a diesel oil with a lot of Magnesium-based detergents. For gasoline applications, I prefer Calcium-based detergents, which leave behind softer deposits in the combustion chambers, making the engine less prone to preignition over the long term. If your engine has low oil consumption, this may not be a concern.

I recall that you used to run Mobil 1 High Mileage 10w40, which is a really good oil. Why did you go away from that one?

 

[A_Harman]

Originally Posted By: aquariuscsm
I'ts an n/a (normally aspirated non-turbo) and I never go over 3/3000. So yeah,conventional is probably the way to go. It was just some food for thought I guess.


Why such short OCI's? Even conventional oils are good for at least 5k miles. How about a 50/50 mix of Valvoline VR1 10w30/20w50? It would have more zddp than your engine was designed for, but that won't hurt anything.

Or here's one that's crazy enough that it may just work:
Shell Rotella T. It's a 15w40, but since you're in Texas, it would be OK for any cold starts you're likely to do. It has all Calcium-based detergency, and ~1000ppm of Phosphorous. The TBN of 9 should easily get to a 6k OCI.

 

[CATERHAM]

Mobil 1 0W-40 with 900 ppm of phos' is plenty particularly for short OCIs.

Just pick up some Mobil 1 0W-40 on sale and be done with it.
It's a much more suitable 40wt to all the other oils mentioned.

 

[dailydriver]

Originally Posted By: Quattro Pete
Originally Posted By: dailydriver
You also have the BC (Belgique Castrol) 5W-40, albeit not on the shelves at Sino-Mart, nor as good as the Mobil 1 0W-40, overall.

Castrol 5w-40 is no longer made in Belgium. However, the new Castrol 0w-40 is.


Yes, I forgot about the replacement/marketing change, thanks.

(But I still think that the Mobil 1 0W-40 is better, and a better deal, overall, than the Castrol product of the same weight.

)

 

[aquariuscsm]

Originally Posted By: A_Harman
I recall that you used to run Mobil 1 High Mileage 10w40, which is a really good oil. Why did you go away from that one?


Well,the Mobil 1 High Mileage seemed to lose its *smoothness* really fast,so I did an oci of Mobil 1 15W50,and suddenly I have a tiny valve cover gasket leak. I did an oci of Syntec 10W40 which runs VERY smooth,alot better than the Mobil 1,and the leak seems to have slowed down. Made me wonder if I'm the victim of the *once you use High Mileage oils and switch off,you'll get a leak* myth. I think my next oci coming up at the end of the month will be GTX 10W40. The Syntec is no longer carried at my closest WM. They said it's been deleted out of their system.

 

[A_Harman]

I'm recalling the reputation of the Nissan VQ engine for shearing oil and wonder what it will do to a conventional 10w40. Does this reputation also apply to the 300ZX engine of the 1990's? This may be a consideration in favor of a 15w40 over a 10w40 if you are going with conventional oil.