Same engine, different year, different oil grade

[Jake54]

05 tucson 2.0L 4cyl, specced anywhere from 5w-20 (only very cold conditions) to 10w-40, oil cap says 10w30.
07 Spectra 2.0L 4cyl, specced at 5W-20 to 10w30, oil cap says 5w-20.
Why the rather big difference in grades that are "acceptable" to use with practically the same engine?

 

[mehullica]

C.A.F.E standards

 

[bbhero]

I agree one hundred percent. My car was specd for a 5w30 all weather or 10w30 or 10w40 above 0°F the generation before mine. Then my generation was specd for a 5w30 only. It does make sense to me that this would lead to a slight increase in fuel economy.

 

[zach1900]

What will it take to convince most bitogers that engines aren't as fragile as most think they are?

 

[cjcride]

I agree with (most)previous posts. I'll add that thinner oil should fill the oil journals quicker and reduce start-up engine wear.

 

[Leo99]

Originally Posted By: zach1900
What will it take to convince most bitogers that engines aren't as fragile as most think they are?


Exactly. And transmissions, too.

 

[bbhero]

I do agree with you on these points. I do find it curious though that everywhere else in the known world that the specifications are different for many of the EXACT same cars than in the US.
Thinner is better but up to a point. If that notion was totally right than every vehicle application should run a 0w-16. Which is not the case just yet

Newer motors are certainly being made much stronger and tighter to make it very plausible for lower viscosities to be able to be run in them safely. I ran the specified 5w20 for 60k plus miles in my Ford Fusion with no issues up until a deer didn't like my car being in the road at 121k miles.

 

[KitaCam]

The Camry I4 is spec'd for 5w30, 5w-20, and 0w-20 for different model years...I'm sure that the engines aren't identical, but....

I thought about this last week when I saw 5w-20 Penn Platinum Plus on sale and unable to pass up a really nice deal, I decided to mix a frankenbrew of 1qt 20w to 4qts 5w30 PP...

Kitacam is spec'd for 5w30, though that was conventional oil, so I have no worry or fear using 5w-20 as the synthetic is I'm sure superior to the dino....

 

[Lapham3]

Some fellas will say 'follow the manu rec' but, yes in most cases the engines are unchanged internally, so cafe and lube improvements/offerings are involved.

 

[fdcg27]

Originally Posted By: zach1900
What will it take to convince most bitogers that engines aren't as fragile as most think they are?


+1
Most engines will run for very long lives on a wide variety of grades.
If you look at the range of SAE grades allowed across various markets for any given engine, it becomes pretty clear that grade is not all that important in the longevity of an engine.

 

[Jake54]

I don't think engines are fragile, I was just wondering about the discrepancy between grades with the same engine, I know 20 grade's film strength is very tough and it can be put through some torture for sure.
It just kind of surprise me that my brothers tundra is rated to use a thinner or oil then my fiances Tucson

 

[Hootbro]

Originally Posted By: Jake54
I don't think engines are fragile, I was just wondering about the discrepancy between grades with the same engine, I know 20 grade's film strength is very tough and it can be put through some torture for sure.
It just kind of surprise me that my brothers tundra is rated to use a thinner or oil then my fiances Tucson


If you ever want to know if a particular engine sold in the USA weight is for CAFE standards, just find a vehicle with the same engine in either the Asian, Africa or South American markets and see what the manufacturers recommend there. If heavier, you know the USA is more about CAFE than actual protection.

 

[TiredTrucker]

Or that the American market is more receptive to lighter oils. Still wanting to see actual data that modern produced motors are suffering any kind of addition wear using a lighter grade of oil, or that the oil is not holding up just fine. Sure, there is the EPA CAFE stuff going on, but that has no correlation to decreased engine protection. It is going to take a long, long time to change the general perception that thicker is better.

 

[Robenstein]

Well in the USA for instance the 2AZFE Toyota engine is speced for 5w30 and some backdated via a TSB to 5w20. However, in Australia, they allow 40 and 50 weights even above 20 degrees Fahrenheit. They don't even mention anything lighter than 5w30 in many manuals.

I think it has to do with CAFE and EPA standards and they are walking right up to the line where going thinner will hurt the protection significantly. When the EPA is mandating pretty big gains in the not distant future for car makers, 1mpg here and there may make the difference between compliance and non compliance.

 

[TiredTrucker]

I don't buy into the lighter is more detrimental idea. When modern 15L diesels are now being factory filled with 10w30 and it is the recommended grade by the same OEM's for use in those bigger engines from the Rio Grande to the Arctic Circle, year round, coast to coast. I know several fellow heavy commercial truck owners and even full fleets that are having great results using 30w oils, where 40w oils were always considered the norm. And as a side note to all of this... there is no CAFE standards or regulatory requirements for heavy commercial class 8 semi trucks. So that argument about CAFE standards determining all of this is pure poppycock. Lighter does not equate to lower protection. Maybe in a 1958 Chrysler flathead 6.

 

[Robenstein]

I don't consider 30wt oils as "thin" considering for many years they made 30 weight racing oils for high performance gasoline engines. Not to mention Rotella has made SAE30 HDEO for years before they made 10w30.

I am talking about 20wt oils becoming the norm in gasoline engines.

 

[super20dan]

my friend seems to have solved his oil burning use in his pos equinox. he switched to 10-30 from 5-20 and its stopped using oil-even on long highway trips.

 

[Jake54]

I just might buy bulk 5w30 for all the gas engines I'd be changing the oil in and call it a day,20wt can protect well too,I've gotten my answer as to why oil grades have differed, it makes sense ig... but, can thicker oil last longer that thinner oil when used in the same engine?