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

[Accent Abuser]

Hmm, OK, but what if you drive your underpowered four cylinder SUV like you're on a track? Then what oil do you use? lol.

0W-40

 

[yowps3]

Let's face it for your average light duty commuter vehicle the lowest acceptable viscosity would be more than suffice, If not actually beneficial since lower viscosoties reduce cold start wear, allow quicker engine warm up, reduce peak operating temperature and allow slightly better MPG & performance.

Now if the application is ultra high speed driving for hours on end under intense conditions than higher HTHS would better serve such purpose.

 

[kschachn]

Let's face it for your average light duty commuter vehicle the lowest acceptable viscosity would be more than suffice, If not actually beneficial since lower viscosoties reduce cold start wear, allow quicker engine warm up, reduce peak operating temperature and allow slightly better MPG & performance.

The only part of that which is correct is the slightly better fuel economy. “Cold start wear” is really not the issue some people imagine it is, and even if it was then the way wear is minimized is by an adequate MOFT. All oils when cold have an adequate MOFT.

And thicker oils warm up faster than thinner ones. But it’s the film thickness when warm that counts so again an oil with a higher HT/HS wins here too.

There is actually nothing beneficial about thinner oils except fuel economy.

 

[tolian21]

UOA is not an absolute determination, it's just another input of information.

 

[yowps3]

The only part of that which is correct is the slightly better fuel economy. “Cold start wear” is really not the issue some people imagine it is, and even if it was then the way wear is minimized is by an adequate MOFT. All oils when cold have an adequate MOFT.

And thicker oils warm up faster than thinner ones. But it’s the film thickness when warm that counts so again an oil with a higher HT/HS wins here too.

There is actually nothing beneficial about thinner oils except fuel economy.

Less viscous oil flows faster.
Water certainly flows quicker than honey and demonstrates increased conductivity, allowing quicker warm up and cool down due to being less dense than honey.
Same principle would be applicable to oils?

Yes film thickness is vital, however, for your average daily drive under reasonable OCI, most 20 grade oils provide suffice thickness.

 

[nicholas]

What's wrong with added MOFT headroom/protection? The argument is nothing ... not that 5W-20 will "blow-up" your motor, but it could cause slightly more wear depending on use conditions compared to a thicker oil based on technical studies. Not trying to say using xW-20 is "bad", and I don't care what others use.

We do 90% short trip driving in cold and sometimes very cold weather.
0w-20 just makes sense for us, the oil very rarely gets to temp.
In the summer on long road trips, I'll run a 30 and 40 weight in our 2 vehicles.

 

[demarpaint]

The only part of that which is correct is the slightly better fuel economy. “Cold start wear” is really not the issue some people imagine it is, and even if it was then the way wear is minimized is by an adequate MOFT. All oils when cold have an adequate MOFT.

And thicker oils warm up faster than thinner ones. But it’s the film thickness when warm that counts so again an oil with a higher HT/HS wins here too.

There is actually nothing beneficial about thinner oils except fuel economy.

+1 That pretty much nails it.

 

[gaijinnv]

Nobody knows how marginal the MOFT headroom is in car X with xW-16 or xW-20 based on every miles it's used in variable use conditions, but it will be lower than if the oil was thicker - a tribology fact for over 100 years and that will never change. When you see statements in OMs that says to use a thicker oil for high loads and high speeds, what do you think the reason was for them saying that. It's because more viscosity gives more MOFT in the same use conditions, and therefore more headroom before MOFT could go to zero and cause wear - there is nothing "misleading" about that.

I agree.

Here's the oil recommendation for my 3UR-FE Toyota 5.7L engine here in the U.S.:

It reads as a very strong recommendation for 0W-20. But it does say that a higher viscosity oil (unspecified viscosity range) may be better under certain use conditions.

And here is the same oil recommendation chart, for the same engine, in the same vehicle, for the ROW:

Several oil viscosities are acceptable based primarily on expected ambient temperature range during use.

Since I live in the high desert where temperatures rarely go below 0 DegF, I choose to run a 5W-30 oil (Mobil 1 EP) which, I believe, will afford a reasonable balance between mpg considerations and wear resistance.

One could argue - if one has a global perspective - that BOTH 0W-20 and 5W-30 are recommended by the manufacturer which leaves the choice up to the owner based on the owner's use conditions.

I don't care what others choose - your vehicle, your choice.

HTH

 

[kschachn]

Less viscous oil flows faster.
Water certainly flows quicker than honey and demonstrates increased conductivity, allowing quicker warm up and cool down due to being less dense than honey.
Same principle would be applicable to oils?

What does flow have to do with it? The only time flow is important is when the oil has to flow to the oil pump pickup tube and not gel under shear. That behavior is described by the winter rating for the oil. After that flow is irrelevant.

And the main influence in oil heating is the shear in the bearings and a thicker oil will warm up faster.

 

[Odd_Ball]

Almost all of these car companies are global and sell product with the same engine in different markets. The biggest tell on this issue is to look at what oils are recommended in markets that do not have CAFE like fuel efficiency mandates. In general, I don't see automakers specifying 0w-20 or 0w-16 oils in those applications.

If these oils gave "just as good" protection and slightly better fuel economy, one would think they would spec the lighter oils globally.

 

[Accent Abuser]

The only part of that which is correct is the slightly better fuel economy. “Cold start wear” is really not the issue some people imagine it is, and even if it was then the way wear is minimized is by an adequate MOFT. All oils when cold have an adequate MOFT.

And thicker oils warm up faster than thinner ones. But it’s the film thickness when warm that counts so again an oil with a higher HT/HS wins here too.

There is actually nothing beneficial about thinner oils except fuel economy.

It's not so much that cold start wear isn't an issue, it's that oil viscosity has little to do with it (as long as the oil can be pumped). Cold start wear is due to part clearances being way out of spec (engine tolerances are designed to be tightest at operating temperature for obvious reasons), fuel dilution, lack of heat necessary to activate the additives, and corrosion from moisture buildup.

 

[Accent Abuser]

I agree.

Here's the oil recommendation for my 3UR-FE Toyota 5.7L engine here in the U.S.:

View attachment 80845

It reads as a very strong recommendation for 0W-20. But it does say that a higher viscosity oil (unspecified viscosity range) may be better under certain use conditions.

And here is the same oil recommendation chart, for the same engine, in the same vehicle, for the ROW:

View attachment 80846

Several oil viscosities are acceptable based primarily on expected ambient temperature range during use.

Since I live in the high desert where temperatures rarely go below 0 DegF, I choose to run a 5W-30 oil (Mobil 1 EP) which, I believe, will afford a reasonable balance between mpg considerations and wear resistance.

One could argue - if one has a global perspective - that BOTH 0W-20 and 5W-30 are recommended by the manufacturer which leaves the choice up to the owner based on the owner's use conditions.

I don't care what others choose - your vehicle, your choice.

HTH

I get virtually (ie tenths of a percent) the same fuel economy from 5w20 and a thick 40 such as Redline 5w40 (KV100 >15cst and an HTHS of 4.4) or Valvoline Maxlife 10w40 (KV100 15.7 cst and an HTHS of 4) so for me there is absolutely no reason to wear out my engine faster using 5w20. I think many others would find going up a grade or two to be the same.

 

[Slow Car Sport Mode]

Here we go.............

This is awesome. You beat me to it

 

[doublebase]

I’m at the point in my mileage where I’m thinking of bumping up the recommended 0w20 to a 5w30 (85,000 miles). It’s a 2GRFE engine, so it probably won’t matter much either way, but I can’t see the 5w30 hurting anything. But is it really helping?

I am curious if people have taken their factory recommended 0w20 oil fills up over 300,000 miles of trouble free engine performance? Not just the occasional one person that says...I’m at 500,000 miles now, all I’ve had to replace is wiper blades. I mean, real stories, lots of them. To the point where I’d feel totally comfortable leaving 0w20 in my car forever.

 

[celicaxx]

Well, one point I don't think has been brought up in the debate is most people do not do DIY oil changes. So most bulk oil is synthetic blend, and at least about 6-7 years ago when I worked at an oil change shop briefly, everything just got bulk 5w30 synthetic blend regardless of what it said on the cap, unless the owner paid for another oil. This maybe has changed now, with more use of 0w20 in everything, but maybe not.

So one thing I think is probably 70+% of cars on the road spec'd for 5w20 would probably run their whole lives on 5w30 with their owners blissfully unaware, and then maybe up to 1/3 or 1/2 of cars spec'd for 0w20 are still getting 5w30 bulk oil. Though to be fair some oil change places are charging an arm and a leg for synthetics now and I've heard of people paying $100 for a basic 0w20 change for a Corolla at say, Valvoline, and getting really upset since they're used to $20-30 bulk oil changes, but plenty of even major chains will still have a waiver you can sign for bulk 5w30 in said 0w20 cars, I believe (at least from reading reviews.)

Just something to add.

 

[doublebase]

Let's face it for your average light duty commuter vehicle the lowest acceptable viscosity would be more than suffice, If not actually beneficial since lower viscosoties reduce cold start wear, allow quicker engine warm up, reduce peak operating temperature and allow slightly better MPG & performance.

Now if the application is ultra high speed driving for hours on end under intense conditions than higher HTHS would better serve such purpose.

The thing I don’t understand, or I’m not able to place is the ultra high speed driving for hours. Because let’s say you commute back and forth to work everyday and you’re driving 100-120 miles a day, in temperatures hovering around 20 degrees, isn’t that taxing on an engine? A lot of stuff happens in a daily commute...hard accelerations, stuck in traffic, cruising along at 75 mph, then slowing down to 50, then up to 80, so on and so on. If you’re doing that everyday, depending on the actual size of your engine and transmission gearing...wouldn’t that be considered harsh? I’m not saying laps around a racetrack harsh, but harsh.

Because I swear, the last few engines I’ve had seemed to consume more oil with these longer highway daily commutes, than the days when I did these easy 20 mile country back road 40 mph drives to work. I know everyone says highway is easy on an engine, but is it really? I’m not saying it’s harder than being stuck in bumper to bumper traffic, I’m just suggesting that bombing up and down the highways every single day for mile and miles, at speeds of 75/80 aren’t exactly a picnic either. IMO.

 

[celicaxx]

The thing I don’t understand, or I’m not able to place is the ultra high speed driving for hours. Because let’s say you commute back and forth to work everyday and you’re driving 100-120 miles a day, in temperatures hovering around 20 degrees, isn’t that taxing on an engine? A lot of stuff happens in a daily commute...hard accelerations, stuck in traffic, cruising along at 75 mph, then slowing down to 50, then up to 80, so on and so on. If you’re doing that everyday, depending on the actual size of your engine and transmission gearing...wouldn’t that be considered harsh? I’m not saying laps around a racetrack harsh, but harsh.

Because I swear, the last few engines I’ve had seemed to consume more oil with these longer highway daily commutes, than the days when I did these easy 20 mile country back road 40 mph drives to work. I know everyone says highway is easy on an engine, but is it really? I’m not saying it’s harder than being stuck in bumper to bumper traffic, I’m just suggesting that bombing up and down the highways every single day for mile and miles, at speeds of 75/80 aren’t exactly a picnic either. IMO.

I think that's being helped by newer transmissions like the 8 and 10 speeds, and CVTs. Even my 5 speed Fusion, as much as I like it, would be 4000RPM at 75-80, and it's near 3000 at 65. Stuff like old Hondas would be 4000 at 65. My mom's Five Hundred with the CVT, though, can cruise at 65mph at 1700RPM or so on flat ground, thus putting a lot less strain on the engine compared to those higher RPMs, imo.

Of course it depends on your highway driving, too, obviously. If you're the type of person to drive 65-70 in the right lane and not try to pass everyone, etc, it's a lot easier than dealing with the drama of constant lane changes and passing.

 

[doublebase]

I think that's being helped by newer transmissions like the 8 and 10 speeds, and CVTs. Even my 5 speed Fusion, as much as I like it, would be 4000RPM at 75-80, and it's near 3000 at 65. Stuff like old Hondas would be 4000 at 65. My mom's Five Hundred with the CVT, though, can cruise at 65mph at 1700RPM or so on flat ground, thus putting a lot less strain on the engine compared to those higher RPMs, imo.

Of course it depends on your highway driving, too, obviously. If you're the type of person to drive 65-70 in the right lane and not try to pass everyone, etc, it's a lot easier than dealing with the drama of constant lane changes and passing.

As i was driving to work this morning I was watching my RPM's...I'm cruising at 72 with rpm's at 1,700-1,800. Not bad, but I've had some cars (because of the tranny, like you said), where they're been at 2,800. And then there are hills to consider - some hills in my area are pretty big and long, and it seems like some work to keep a car at speed going up. You hear that tranny shift into a favorable situation to handle it...the rpm's go up. It's not a big deal, I know, but for some vehicles it might be. And is it just me, or has highway driving speeds gone up this year? I can't even do 72 in a 65 without being driven off the road! It's getting crazy out there.

 

[Accent Abuser]

The thing I don’t understand, or I’m not able to place is the ultra high speed driving for hours. Because let’s say you commute back and forth to work everyday and you’re driving 100-120 miles a day, in temperatures hovering around 20 degrees, isn’t that taxing on an engine? A lot of stuff happens in a daily commute...hard accelerations, stuck in traffic, cruising along at 75 mph, then slowing down to 50, then up to 80, so on and so on. If you’re doing that everyday, depending on the actual size of your engine and transmission gearing...wouldn’t that be considered harsh? I’m not saying laps around a racetrack harsh, but harsh.

Because I swear, the last few engines I’ve had seemed to consume more oil with these longer highway daily commutes, than the days when I did these easy 20 mile country back road 40 mph drives to work. I know everyone says highway is easy on an engine, but is it really? I’m not saying it’s harder than being stuck in bumper to bumper traffic, I’m just suggesting that bombing up and down the highways every single day for mile and miles, at speeds of 75/80 aren’t exactly a picnic either. IMO.

Not the way I drive.

 

[wemay]

Are we really doing this again?