Thickening Oil

[surfride]

If the problem is thickening oil at startup, not thinning oil. Why do manufacturers recommend oils with a flow rate at that could be better for startup? If the target is 10 at 212, and they all get there 0w30, 5w230, 10w30, 30; with the only different being flow when the engine is cold, then it seems logical 0w30 is the choice, yet none of my vehicles recommend this. Chrysler has my 4.0 liter jeep at 10w30, GM has my 8.1 liter at 5w30 and my duramax at 15w40. regardless of location (I am in San Diego) and most wear occurs at start-up, then why not recommend 0w30?

I do all my vehicle maintenance and this is provocative, raising questions... There most be another element to the equitation.

 

[SwampSurvivor]

Older oils with wider spreads used to sheer - so a 5w30 would drop itself to a 5w-20 pretty quick in a Jeep 4.0. Modern oils aren't so bad about it.

Plus, I'm sure suggesting cheap 5/10w-30 keeps maintenance and ownership costs down quite a bit over the 200K life of the vehicle.

 

[UNC017]

Its oft been contended on here that modern 0w40 is darn near a universal oil. I tend to agree, though I don't bother to use it in applications where a 5w20 or 5w30 are called for.

As others have said, older oils sheared a lot more than they do today, and especially in diesels there's just a long history of using 15w40 that has been slow to go away. More and more you see 5w40 synthetic being used, though.

So really it comes down to cost. To get a 0w30 or 0w40 that doesn't have a ton of VIIs to deteriorate, shear, and create sludge it takes a very good synthetic base stock and carefully formulated additives. For the vast majority of vehicles out there, a 5wXX or 10wXX is "good enough" and can be a lot cheaper.

 

[4wheeldog]

Actually, in temperate climates, there is no difference in viscosity at startup between a 0W/XX and a 15W/XX. It is only when you get well below 0F that the difference becomes an advantage. So.....Unless you live where it gets really, really cold, the winter number is not as important as you might think.

There are other differences (Besides winter number) that make truly premium oils, which happen to have the OW designation, worthwhile. But the OW number, in and of itself, does not make much difference in a climate where it never gets below 20F.

 

[Nick1994]

The difference between a 5w30 and 0w30 at startup at a temperature that isn't EXTREMELY cold is very minimal. Your 4.0L Jeep needs a 10w30 for shear protection, so it doesn't go down a grade. Most car manufacturers now spec 0w20 these days anyways so yes they are moving in that direction.

 

[fredfactory]

Good question. Certainly to be a 0w30 you have to be a synthetic, as we see in the marketplace. So manufacturers are not ready to specify synthetic-only. >>>> Therefore, if your car calls for a conventional 10w30 minimum, then you could run an excellent 0w30 full-syn and do better in a cold climate for startup, and the manufacturers should state that.
In the case of BMW, they always specify full synthetics, and they still have their BMW house-brand oil as a 5w30 in LL-01 form, and that is strange, as I don't know why they don't just say 0w30 or 0w-40 in LL-01 only please.....

By shear-down, is this just the Viscosity Index Improver VII chemically breaking apart as miles/heat accumulate? If thats the case, why not specify adding in pure VII chemicals half-way through an oil change interval?

 

[CT8]

Originally Posted By: surfride
If the problem is thickening oil at startup, not thinning oil. Why do manufacturers recommend oils with a flow rate at that could be better for startup? If the target is 10 at 212, and they all get there 0w30, 5w230, 10w30, 30; with the only different being flow when the engine is cold, then it seems logical 0w30 is the choice, yet none of my vehicles recommend this. Chrysler has my 4.0 liter jeep at 10w30, GM has my 8.1 liter at 5w30 and my duramax at 15w40. regardless of location (I am in San Diego) and most wear occurs at start-up, then why not recommend 0w30?

I do all my vehicle maintenance and this is provocative, raising questions... There most be another element to the equitation.







The start up wear has little to do with the oil when the proper viscosity oil is used for the start up temps. Disregard oil 101.

 

[HTSS_TR]

Honda S2000 from model year 2000 to 2009 oil spec for temp above 0F "Conventional 10W30", synthetic can be used but must stay with recommended grade which is 10W30.

But XOM recommends by order: Mobil 1 Extended Performance 10w30, Mobil 1 Advanced Fuel Economy 0W30, Mobil 1 10W30, Mobil Super Synthetic 10W30 ...

The second of several choices is 0W30, XOM is very confidence about their Mobil 1 Advanced Fuel Economy oils shear stable to recommend it above Mobil 1 10W30.

As posted by above poster, 0W30 is only available in synthetic and manufacture may recommends dino for low maintenance cost, therefore 10W30 is their choice for shear resistance.

 

[Nate1979]

Originally Posted By: surfride
If the problem is thickening oil at startup, not thinning oil. Why do manufacturers recommend oils with a flow rate at that could be better for startup? If the target is 10 at 212, and they all get there 0w30, 5w230, 10w30, 30; with the only different being flow when the engine is cold, then it seems logical 0w30 is the choice, yet none of my vehicles recommend this. Chrysler has my 4.0 liter jeep at 10w30, GM has my 8.1 liter at 5w30 and my duramax at 15w40. regardless of location (I am in San Diego) and most wear occurs at start-up, then why not recommend 0w30?

I do all my vehicle maintenance and this is provocative, raising questions... There most be another element to the equitation.





How many 0w30 brands are you aware of?

 

[sicko]

Until recently, any 0w oil had to be synthetic. So requiring 0w oil would mean requiring synthetic oil, and thus increase the cost of ownership which manufacturers are constantly trying to reduce.

Also add to it that people not understanding what 0w means, think that it's "too thin" to protect.

Plus, until recently, there weren't many 0w oils even available.

Lastly, for the vast overwhelming majority of people, there is very little difference between a 0w and 5w at start up. I know people don't want to hear that, but in most normal weather the difference isn't much. It's only in extreme cold that the difference really grows.