Logic behind using 0W30 in a 0W20 vehicle

[demarpaint]

Originally Posted By: 4WD

And too many OEM are now pushing a brand - we have enough marketing bull without that ...


Good point, I forgot about that.

 

[Jetronic]

Originally Posted By: Nickdfresh
Originally Posted By: Jetronic
Originally Posted By: dblshock
nothing worse than another sheeple adding a qt. of 0/20 1200mi. into his OCI.


Cars with such a consumption get a new engine under warranty, or get scrapped, here in Europe. I doubt you'll get it through the inspection anyway. Leaks aswell as poor combustion will get you a ban.


And it doesn't actually happen. Just sheeple trolling on about anecdotes that are rarely seen here...


That consumption isn't normal, period. I'm not saying it's caused by to xW-20 use but half the world doesn't accept that kind of consumption.

 

[bluesubie]

Originally Posted By: SubieMovie
I have a Crosstrek that requires the use of 0W20, but I wanted to know if it is recommended and safe to use 0W30 in the Crosstrek engine?

What are the pros and cons of such a move?

I'm a huge fan of going thicker than recommendations when necessary, especially in a turbocharged Subaru, but I don't think there would be much to gain by switching to a 0W30 in a 148 hp Crosstrek. I know some of the earlier oil burner 2.0 owners experimented with thicker oils, but we now know that was more of a manufacturing problem. It probably won't make much of a difference either way, but give it a shot if it makes you sleep better at night and your dealer won't give you warranty hassles.

 

[fdcg27]

Most makers have recommended but one grade for at least a couple of decades now.
Doesn't mean that a thinking man can't use something else. We just have to consider conditions and what we hope to accomplish. Going up or down a grade isn't likely to harm any engine, although I'd be hesitant to go down a grade in a vehicle used for towing or in extended drives during hot weather just as I'd be hesitant to go up a grade for a commuter car during the depths of a Northern winter.
There was indeed a day when every OM had a temp/visc chart that allowed for the selection of a grade based upon expected ambient temperatures. Makers probably learned the hard way that offering choices would inevitably lead to inappropriate ones for the weather conditions encountered. The OM of our '09 Forester even allows for the use of HD 30, HD 40 or 20W-50 under extreme conditions.
Can you imagine some numbskull putting one of these grades in his 2.5 in December in Ohio? I'd bet a beer that it's happened.
The manufacturers have little faith in the mechanical savvy of today's buyers with good reason. The reason that the recommended grade is emblazoned on the oil fill cap is that the makers know that most of their customers won't trouble themselves to read the OM and also to preclude the use of some wildly inappropriate grade by the local Quicky Lube that most owners will use since they're too clueless and lazy to do their own maintenance and too cheap to use a real shop.
People do cheap out in maintaining the vehicles they depend upon to keep a job and to keep food in the house, but that's a whole different topic.

 

[BrocLuno]

I think we've all been left to ourselves... The OP has not been back in 7 pages and the rest of us are going over long standing arguments...

 

[4wd]

Well, I once mixed a 7w25 ... let's go with that and shut this down ...

 

[aquariuscsm]

Originally Posted By: BrocLuno
I think we've all been left to ourselves... The OP has not been back in 7 pages and the rest of us are going over long standing arguments...


Haha you're right! He hasn't responded a single time

 

[JHZR2]

Originally Posted By: dblshock
and if you love 0/20 just have the engine rebuilt at 80k, so what.


hmmmm... https://bobistheoilguy.com/forums/ubbthreads.php/topics/4259719#Post4259719

 

[JHZR2]

Originally Posted By: Shannow
Originally Posted By: JHZR2
I agree that a fuel diluted 20wt could be a concern, granted Ive seen those and its not that bad in terms of viscosity. Im not yet concerned that a sheared 20wt oil is a big concern these days.

IIRC, one of the arguments early on in the 2000's wave of 20wt oil specs, was that the typical (at the time) conventional 5w30 would shear to the high end of the 20wt range, while the new 20wt specs tended to produce a lube that was in the more viscous end of the 20wt range, with better specified shear stability (which drove to other base stocks, etc).

Meanwhile, cross the manufacturing element. Bearing clearances have changed little over the years but the asperities have been minimized allowing thinner oils to be used.


If you recall also at the time, the 20s ALWAYS stayed in grade, as the grade at the bottom end was ridiculously low, based on the original method of "time through a viscometer" of defining grades.

Fixing that with the introduction of 16, 12, and 8 has seen lots of 20s out of grade, and mostly fuel diluted as you suggest...boundary additives and polymeric coatings are the new world, replacing hydrodynamics for much on a bearing's life.


"much" of its life? Sort of doubt that.

If manufacturers decide they can back-spec 0w-16 to 20 wt vehicles, I suspect that it will imply that the 20wt oils going out of grade is OK.

However that is achieved, assuming it ensures economical performance over the engine's lifecycle, is essentially the same. If boundary lubrication 50% of the time allowed 200k worth of life and higher MPGs, would/should anyone really care?

If DBW ensures that the transient conditions are tempered so that bearing loading is maintained at a better regime, does any of this retain the same importance? IIRC, a fairly blocky vehicle cruising steadily at 60 MPH, requires about 60 HP. Far from high load in an engine rated at 150+, which is the norm these days. Then it may come down to transient behaviors and their effects.

I agree that they will go out of 20wt grade. I have a fuel diluted 0w-20 used oil analysis to show that. But is it really a reason for concern? Especially if the engine can remain operating well and with low fuel and oil consumption prior to the body rusting out?

 

[tig1]

Originally Posted By: dblshock
and if you love 0/20 just have the engine rebuilt at 80k, so what.


That hasn't been my history with 0-20 oil.

 

[Shannow]

Originally Posted By: JHZR2

"much" of its life? Sort of doubt that.

If manufacturers decide they can back-spec 0w-16 to 20 wt vehicles, I suspect that it will imply that the 20wt oils going out of grade is OK.

However that is achieved, assuming it ensures economical performance over the engine's lifecycle, is essentially the same. If boundary lubrication 50% of the time allowed 200k worth of life and higher MPGs, would/should anyone really care?

If DBW ensures that the transient conditions are tempered so that bearing loading is maintained at a better regime, does any of this retain the same importance? IIRC, a fairly blocky vehicle cruising steadily at 60 MPH, requires about 60 HP. Far from high load in an engine rated at 150+, which is the norm these days. Then it may come down to transient behaviors and their effects.

I agree that they will go out of 20wt grade. I have a fuel diluted 0w-20 used oil analysis to show that. But is it really a reason for concern? Especially if the engine can remain operating well and with low fuel and oil consumption prior to the body rusting out?


Note, "much of" isn't "most of"...

the new engine tests explore the mixed regions more, as that's where the OEMS are putting their engines for more of their operating life.

Start stop technology is by definition in boundary every time the engine stops...and the OEMs and bearing manufacturers are making polymeric coatings to improve life under these conditions...if they were in full hydrodynamic, then there would clearly be no reason...there's no contact.

Your final point is one that I've been suggesting for years...sacrificing the life of componentry for the 100,000 mile AFTER they have been junked, for better economy for the operational life is a sound trade-off.

It's just that Consumers (and a lot of BITOGers) don't want to admit that these trade-offs are being made.

edit...Solarent had a good thread on industry moves
https://bobistheoilguy.com/forums/ubbthr...mp;#Post3929056

Again, if you are relying on chemistry and tribofilms rather than hydrodynamics, then you have reduced the hydrodynamic film thickness to the point that contact is being made...

 

[BrocLuno]

There is no 100,000 after junking in my yard. Everything starts life (for me) at 100,000 so I care about late life sacrifices and trade-off's.

I don't live in the rust belt or near the ocean. I've got two 1970 chassis in the yard. They never would have gotten here on that sort of trade-off.

I'd a got p*ssed off and sold them long ago and never gone near another from that MFG if I knew they were making the trade-off (unless it was a good running Porsche for under $5K

) ...

 

[Yah-Tah-Hey]

Meme pool

 

[Nickdfresh]

Originally Posted By: Jetronic
Originally Posted By: Nickdfresh
Originally Posted By: Jetronic
Originally Posted By: dblshock
nothing worse than another sheeple adding a qt. of 0/20 1200mi. into his OCI.


Cars with such a consumption get a new engine under warranty, or get scrapped, here in Europe. I doubt you'll get it through the inspection anyway. Leaks aswell as poor combustion will get you a ban.


And it doesn't actually happen. Just sheeple trolling on about anecdotes that are rarely seen here...


That consumption isn't normal, period. I'm not saying it's caused by to xW-20 use but half the world doesn't accept that kind of consumption.


It also never happened!

 

[Shannow]

So there was really no reason whatsoever for the OEMs to define woeful consumption rates as "normal", and cut back the phosphorous to protect the cats with such consumption ?

Why go to the effort then ???

 

[turboseize]

Not everything makes sense.

Just look at VW: they required very low-SAPS to protect DPF. Mercedes on the other hand allowed mid-SAPS, but required much better NOACK. Seems like the guys in Stuttgart figured out that you can get away with higher Ash content when they make sure less oil gets to the DPF in the first place...

 

[Swifty]

0W30 in a vehicle spec for 0w20... because you can or choose to, and it is your vehicle, best logic of all. Not everyone buys into the CAFE bandwagon. The difference in MPG may very well be measurable but it is not really that significant. I tracked my fill ups for 6 months on 0w20 and then 0w30 on the next 6 months using the Fulieo app. and the difference was .2 mpg in favor of the 0w20 over the same amount of fill ups on each.

Regardless of which choice you make your vehicle will go many, many miles on either.