Why does xw20 and xw30 show essentially the same/similar UOA but people blame cafe?

[CharlesInCharge]

MOFT and headroom. Give me a break already. 255,000 miles on the old F150 and it runs better than new and uses no oil in 5k OCI's on 5w-20 oil. How can that be???

"Better than new" seems like an impossibility, esp at a quarter million miles, which undercuts your point and credibility on the topic of discussion.

 

[ZeeOSix]

I see cars here on the roads that are 40 years old and have no rust. Rusting out is basically a zero concern here - rarely snows and minimum salted roads when it does snow.

 

[tcp71]

The first year of ford’s 3.5 twin turbo eco boost was spec’d for 0w20. That was quickly changed to 0w30 within the first year it was used in the F150 and started towing larger loads. Why change if the 0w20 was “good enough”? Because it needed a heavier oil in that application. Thicker oils have their place.

 

[4WD]

Nobody has to believe the facts around it. People typically make decisions based on facts. But some do based on feelings and antidotes (ie, it didn't blow-up or went 200K miles and still "runs good"), but it's all good.

Seems that people who hear that thinner oil gives less MOFT and possiby less wear protection in some use conditions get upset over it.

and I did not take a position on thick vs thin - just on use of UOA’s on this site.

 

[ZeeOSix]

and I did take a position on thick vs thin - just on use of UOA’s on this site.

What was your position on thick vs thin?

 

[4WD]

What was your position on thick vs thin?

Sorry - driver was outside and left out “not” in a hurry
Updated now

 

[demarpaint]

Nobody is "blaming" CAFE for anything except to push xW-20 in OMs and on oil fill-caps in many vehicles that use to spec xW-30 weight or higher in order to make people think that their car was specially engineered around an oil viscosity. And we know that's not true from the many OMs for the same cars sold in other countries showing a whole spectrum of acceptable viscosity. And many studies show that using thicker oil can give more wear protection. It just so happens that most vehicles will last a very long time on xW-20, so it makes it even easier to push the thinner oil - rightly so in relatively benign use conditions. As you know if reading a lot here, a few manufacturers have went back to xW-30 on vehicles where they use to recommend xW-20. Ford did that for the 2021+ 5.0L Coyote V8 in the Mustang and F-150. Previous years specified 5W-20. Go figure ... could be the engineers knew 5W-30 gives more engine protection - what else would be the reason. IMO, the Coyote should have had 5W-30 since the begging ... but it took Ford 10 years to get to that point.

I recall reading a while ago that Ford had changed a few engines back to 30 grade oil from 20 grade oils because they were having problems, and to reduce warranty claims. That seems to coincide with what you mentioned earlier. I wish I could find where I read that. Perhaps the cost of the warranty claims exceeded the CAFE credits in the applications in question. Either way this turned into another thick vs. thin battle as predicted.

 

[ChrisD46]

I used to be in the thick camp but I'm not anymore. The difference between API w30 and w20 is very little, just look at the operating CST 100 ranges. Sure, theres a difference in HTHS. But for the average driver with an automatic dropping revs as fast as possible, this makes no difference. Use what they spec, unless you're hitting the track or something.

*Just curious - I believe your Kia Optima 2.4L is spec'd for 5W20 on the oil cap - yet you elect to use 5W30 (also permitted from the Kia OM) ... Why didn't you stay with 5W20 ?

 

[Odd_Ball]

You might look into what those same car companies recommend in the same engines sold in non-CAFE markets. This is the answer you seek Grasshopper.

 

[FZ1]

Do we have some uoas on the same car ,same driver, apprx miles with a 20w vs. a 30w for comparison?

 

[kschachn]

Do we have some uoas on the same car ,same driver, apprx miles with a 20w vs. a 30w for comparison?

It wouldn't matter even if you did, for several significant reasons.

 

[wpod]

most people seem to forget the oil keeps the parts separated and from sticking until the oil is too thin to keep the parts separated.

 

[wpod]

Maybe it’s the region you live in? Where I live newer cars are the norm. Older cars, say 15 years or older are becoming less and less.

I look at the UOAs and the only high mile cars are the ones bought used with the high miles as a general observation.

 

[wpod]

"Better than new" seems like an impossibility, esp at a quarter million miles, which undercuts your point and credibility on the topic of discussion.

I had a 1979 F150 with 300,000 miles when I sold it and it still hand normal oil pressure using a mechanical oil pressure gauge. And ran great . Just proper maintenance.

 

[PimTac]

I look at the UOAs and the only high mile cars are the ones bought used with the high miles as a general observation.

I missed something here.

 

[haggler]

*Just curious - I believe your Kia Optima 2.4L is spec'd for 5W20 on the oil cap - yet you elect to use 5W30 (also permitted from the Kia OM) ... Why didn't you stay with 5W20 ?

It's what I had. I'll use castrol 5w20 EP or M1 10w30 EP next or whatever else is in my stash. Thankful for some warranty leeway in Kia's OM. Makes it easier to score stashes

 

[Danh]

Assuming using a spec’d 0w-20 normally has no impact on engine life, what about when used in a DI/TGDI engine that introduces fuel dilution? There are lots of UOAs here that show 20 weights in these engines that have diluted or sheared below the 6.9 cSt 20-weight minimum viscosity. Safe to assume OEMs have factored this into recommendations and it still won’t make an engine longevity difference? Or is this a circumstance where going up a grade would be more than an emotional decision?

 

[wpod]

I missed something here.

Look at the uoas . There are not a whole lot of high mile vehicles.

 

[Silver]

Since Xw20 oils have been widely adopted over the last 10 years, maybe a better approach to address the 'Xw20 doesn't protect enough' crowd would be to look at the average age of vehicles on the road.
if the Xw20 is truly inferior, overall vehicle age would decrease because the Xw20 is not good enough to provide long life and the vehicles would be off the road.

And yet the average age of a used vehicle is the oldest it has ever been. So that Xw20 must be doing something right. No matter what the naysayers are spouting.

Or, maybe the newer x20 engines are wearing out so fast, the vehicle still has life left in it so they're just replacing the engine.

I have no idea, just offering another perspective. Admittedly a quite bizarre one but my point is we just don't really know.

 

[ZeeOSix]

Assuming using a spec’d 0w-20 normally has no impact on engine life, what about when used in a DI/TGDI engine that introduces fuel dilution? There are lots of UOAs here that show 20 weights in these engines that have diluted or sheared below the 6.9 cSt 20-weight minimum viscosity. Safe to assume OEMs have factored this into recommendations and it still won’t make an engine longevity difference? Or is this a circumstance where going up a grade would be more than an emotional decision?

I don't own any DI vehicles, but if I did and it specified xW-20 I'd certainly up it to 5W-30 for that reason along.