What do y'all think of 5W-20?

Yes, that is an oft-repeated rumor.

Lemme tell a funny story. When I was at the dealership sitting in my new car, with the salesman giving me the mandatory rundown on all the gizmos, there happened to be a new Prius parked nose-to-nose right in front of me. As we discussed the transfer case lever I joked that the 4Runner could probably drive right over the Prius. The salesman raised a finger and said that we 4Runner owners should be thanking the Prius on blended knee. He explained about the CAFE standard, and that the fuel consumption target was fleet-wide, and that it was thanks to the high mpg and high sales volume of the Prius that the 4Runner doesn’t have the idiotic auto-stop-start. Now, I gotta believe that the fuel savings from the auto-stop-start is much greater than just running thinner oil, and if Toyota needed to wring another .001 mpg out of the 4Runner they would have added an auto-stop-start. As the auto-stop-start remains absent, I’m not sure the rumor about thinner oil being spec’d to satisfy CAFE standards is valid.

 

I thought everyone already knew that it was fleet average, hence the F in CAFE.

Just because we don't have auto start doesn't mean that fuel economy wasn't a factor in the decision.

 

First off, engineers make recommendations. Executives make the decisions.

Second, even the engineers are weighing multiple and competing priorities. There’s no single ideal viscosity for any engine.

Every choice involves compromises. Like with tires. You want maximum braking and cornering performance? Well then the tire will suck in the snow. You want good snow performance? Well then the tire will suck in rain and dry braking, and will wear out quickly when it’s warm.

The drivetrain engineers have to weigh longevity against performance. And MPG. And economics. And environmental concerns.

Anyone who really believes that 0-20 produces the greatest longevity in the 1GR should have their heads examined. Doesn’t mean it wasn’t a sound choice by the engineers (or the executives). But it’s just silly to conclude that it’s recommended because it makes the engine last longest.

It’s recommended by the manufacturer because it was judged to yield the best overall compromise between the manufacturer’s competing priorities.

Owners are entitled to have different priorities. Some of us prioritize longevity over MPG.

 

What we know:

• In the owners manual of a 4Runner in Chile there is more latitude given regarding oil viscosity. (although on the chart it says 0-W20 is “preferido”.)
• In the U.S., the manual says to use 0-W20, or 5-W20 in a pinch.

What we don’t know:

• Why did Toyota choose 0-W20?
• Was it engineers or somebody else at Toyota who made the choice?
• Did CAFE have anything to do with the decision?
• Does 0-W20 provide inadequate protection?
• Does 0-W20 actually offer improved mpg over heavier oils?

I’m not telling anyone which oil they should be putting in their vehicle. What I am saying is that if you are going to deviate from the manual’s specification, that choice should be made on solid information rather than assumptions and guesswork.

 

Agreed.

To add to your point:

Here are some pictures from the 2019 manual.

Note that it mentions 0W-20 being the best choice for fuel economy and cold starting, not protection.

Also note that the Puerto Rico section recommends 0W-20, 5W-20, and 5W-30 for ANY temperature range, and only suggests that 10W-30 not be used below 0°F, and 15W-40 not be used below 10°F. There is no maximum ambient temperature recommendation for any viscosity.

It also states that an oil with a higher viscosity may be better suited if the vehicle is operated at high speeds or under extreme load conditions







@Captain Spalding , this isn't guesswork or an assumption. This is right in the manual.

 

Exactly.

 

Off topic, but the lack of direct injection on our 4runner (and the lack of engine oil smelling like gasoline) is a big reason I like mine so much. I had a 2011 Kia optima with direct injection…otherwise a fine car, but that oil was nasty at 4000miles.

 

Where in the manual does it say that 0-W20 provides lesser protection to the extent that using it will affect the longevity of the vehicle? This, sir, is your assumption.

Edited to add: @Thatbassguy: I’m not trying to pick a fight with you at all. I consider you to be one of the anchors of this forum, and find your many posts to be helpful and generous. I’m just pointing out a logical flaw that pervades this thread.

 

Where have I ever said that??

All I have said is that oil with higher viscosity is recommended in some circumstances. And that the manual states that 0W-20 provides the best fuel economy and cold starting. It doesn't specify that any viscosity provides better protection than the other.

But, it does say that a higher viscosity might be ideal for high speeds and extreme load conditions. That suggests to me that I might get better protection from a higher viscosity, based on how I drive.

 

I like the way this post makes me feel. Good enough for me lol

Since I have a 21, my owners manual indicates 0w20 as recommended. It has the disclaimer that higher viscosity oils may be better when operated at high speed (what’s that anyway), or other conditions. It doesnt even mention what those higher viscosity options might be either.

I find it curious the disclaimer is mentioned in a mumbly kind of way, and with shifty eye contact. Kinda like “nothing to see here, move along”. Hmmm….I think there is (italics!!!) something to see here! Thank you very much! I’ll take liquid ball bearings please

 

I don't know what they consider "higher speeds", but I usually keep mine in S4 when I have the MT's and the roof rack on. So, I'm hanging around 3,000 RPM's on the freeway. This feels like abuse, even though the engine doesn't seem to mind at all.

 

Got the manual just to make sure I wasnt misremembering. Precisely as I recalled!

 

320K miles on a 2014 using 0w20 synthetic at 10K mile change intervals. Nothing imprudent about that.

 

Disclaimer: I am not an oil expert. I found this blog recently and have spent quite a bit of time learing. I understand the chemistry of polymers and why a PAO and Polyester provides better film thickness during cold start ups but did not understand the critical role additives play in performance until reading this blog.
Here is a clip from the many pages of oil performance discussion.
"So, as you can see, this is absolute PROOF that viscosity does NOT determine an oil’s wear protection capability, even though many people mistakenly believe it does. As mentioned above, an oil’s wear protection capability is determined by its base oil and its additive package “as a whole”, with the primary emphasis on the additive package, which contains the critical extreme pressure anti-wear components. And the additive package has nothing to do with viscosity."

It is a very long read but you can skip to his oil rankings or any other interest by following the instructions below. The writer is a mechanical engineer and hobbyist engine builder. He seems to really know his stuff. He has ranked many oils based on compression strength and has a long list. See where your oil ranks.
540 RAT - Tech Facts, NOT Myths (wordpress.com)

HOW TO SEARCH ON THIS BLOG:
Press the F3 key, or press “ctrl F“. Type in what you are looking for, in the FIND window at the top, and it will show the number of matches found, at the top. It will highlight those matches in yellow, and will take you right to the first match.

Here is a clip from his blog:


Also, I am not advocating Amsoil btw, but here is a good overview of additives, base oil, etc. for those who have not seen.
Additives in Motor Oil: Everything You Need to Know - AMSOIL Blog

 

Interesting stuff. He also says this:

"Ford Motor Company changed the motor oil spec on their 2021 High Performance V-8 Mustangs from 5W20 which had been the spec for years, to 5W30 which readers of my Blog know that I have been recommending for most water-cooled, gasoline engines for years. So, Ford has either been reading my Blog, or they independently arrived at the same conclusion I did years ago."

 

@Captain Spalding , I think you misunderstood what I meant here:

What I meant was that it only says that 0W-20 is best for fuel economy and cold starts, and doesn't specify that it offers the best protection. I probably could have been more clear.

I appreciate your contributions to this forum as well!

 

This internet is an amazing place. Hang in long enough and you'll become famous.
540 RAT started his oil testing on a Corvette forum. I remember when he started and has since changed his conclusions and reasoning numerous times. He started using a simple pressure friction test which largely subjective and very non scientific.
Here is a link to the latest iteration of his results. AFAIK he is simply a Corvette hobbyist.
https://www.corvetteforum.com/forum...56-motor-oil-wear-test-and-lab-test-data.html
You could do a search on his name and get all the original posts. There was a lot of controversy.

There was also a paper written by a chemical engineer in the oil biz that gave some decent results on viscosity testing and yes he claims it does make a difference and I can attest to a part of that.
Years ago I bought a C3 Corvette that came OEM with a Gen1 small block. As with any of those engines when new to me, I always adjusted the valve lash along with other tune items. With the engine cold and the valve covers off, I started it and waited for it to warm up to operating temp. To my astonishment NO oil was reaching the valve rocker arms until the engine was at full operating temps. This was easily 10 minutes. Not good. Before going any further, I dumped the oil and put in M1 0w-40. This time with the engine cold, upon startup, oil reached the rockers within a couple seconds.
Needless to say ever since I've been using M1 0w-40 in everything else, with the 4Runner M1 0w-20, might go to the new M1 0w-30
The key is to use 0w for cold startup especially in sub freezing temps. This guy claimed it would reach full lubrication over twice as fast as the next grade up, 5w. I have a Ford Lariat V8 with 280k miles using the M1 0w-40. Uses no oil with no issues.
Another viscosity issue is the hydraulic VVT on the original Ford engines. Put too heavy an oil in and they would simply not run right. Correct valve timing was inhibited.

Those are the only items I'll bore you with.

 

I'm a retired engine engineer and I run Mobil 1 in my vehicles at the manufacturer's recommended weight. Totally agree that you want the 0W for cold starts since you want pressurized oil to get to the moving parts as quickly as possible. As far as 20 weight not being thick enough for a 4Runner I think that all of the design validation done by the manufacturer was done using the recommended oil weight (manufacturers run brutal durability testing on dynamometers that a customer cannot duplicate, then they run brutal durability testing in real vehicles under all loads and temperatures that the vehicle may experience). Then quality is monitored throughout a vehicl's productin and design tweaks may be made if needed. All of the data behind the 4Runner's outstanding reputation is for vehicles with the recommended viscosity. If you try to outsmart the manufacturer you are at risk of unintended consequences; perhaps heavier oil will gum up your piston rings sooner or create more soot and mess up your valves or catalyst or screw up the hydrodynamic lube of your main bearings that have clearances optimized for 20 weight or cause your lash adjusters to fail sooner or or or or or. I wouldn't get too excited about seeing a higher viscosity called out as OK for Puerto Rico or super severe use because under those unique conditions the oil will always be hotter than "normal" so the effective viscosity of the oil is lower and you end up being basically where the manufacturer intends.

 

Well said, now can we please put this thread to rest?

 

For the millionth time, nobody is taking about using a higher viscosity oil than Toyota recommends. Look back a few posts and read the text in the screenshots directly from the manual.

 

this comes across as legal-speak for using higher RPM's and under greater load for extended periods. i strongly doubt their legal department would authorize them being able to call out a specific speed (too many variables, or in the event it lead to an accident) but what the engineers are aiming at here is if you put more strain on the engine, a higher viscosity is a reasonable option.

on an aside, i always found the Puerto Rico thing hilarious. As if there aren't multiple areas of the US that are far more extreme in climate (both hot and cold), altitude, steep grades, and humid marine air.

 

Agreed. This is why I figured I could benefit from higher viscosity. Mine lives at ~3000 RPM's for hours at a time in the summer, on top of being constantly loaded down and on oversized tires.

 

I see your manual calls for ILSAC GF-5 oil but 2022 manuals call for much better ILSAC GF-6A oil which I believe is also backward spec'ed.

 

I'm in S Florida and the temps here are brutal. At least the same if not hotter than Puerto Rico. City driving here alone is severe use, with higher rpm and towing even worse. As I said I'll likely switch to M1 0w-30

FYI
From the FJ Manual (same engine) in the Gulf states (Persian Gulf), not CAFE limited.

"For temperatures from 20F to 100F+, 20W-50 is recommended"

 

trust me man i know how miserable it is. east GA here. we hit 101 degrees in October in 2019.

FWIW, i did 1700 straight miles last spring with the T4R loaded down and pulling a camper (just like what you see in my avatar) over 3 days in S4 exclusively. 3000 RPM for full days. after i got back i ran an analysis on the run of 0W-40 i used and the results came back stellar, essentially no difference in wear metals to normal daily driving. you're good to go.

 

I did read the owner's manual stuff and I do understand your point. Maybe that's the key bottom line, that the engine is tolerant of a range of oils. The data shown by Foothills suggests that there's significant variation across brands and my Mobil 1 0-20 may be a bit thicker than Genuine Toyota 0-20. All I'm saying is that the vast majority of testing behind the 4Runner and the quality checks still done in the engine and vehicle assembly plants every day are going to be with 0-20 so I believe 0-20 is "most proven".

 

Good points. I just think that, if the manual recommends higher viscosity for high speeds and extreme load conditions, I might qualify for it.

 

Wow! Certainly not imprudent. Did you take it in for oil changes, or do it yourself? After that many miles, have you noticed any increased oil consumption?

 

Couldn't find any 0-20 at walmart so went with 5-20. Havoline had the best deal on 6 quarts for $22. Came in a bag that was in a cardboard box.