Toyota 4.0 v6 0w20 oil? Wtf?

DaveInDenver

Expedition Leader
Another data point, 2016 Tacoma 2GR-FKS. Notice that they changed the crankshaft oil clearance from a standard with a maximum to standard with a minimum. Just a weird change in terminology.

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shade

Well-known member
Note that oil has come a long way in the last 20 years, and most SAE 20 oils have high shear viscosity, but lower static viscosity.
I think you missed a critical e, but otherwise, yep. There's a series of articles on BITOG about the value of using lower viscosity oil at startup. The author dispelled some of the thicker-is-always-better arguments. I found the series worth the time.

I'm considering 0W-40 for a specific use case where I expect high load (towing a box trailer over mountains) and high heat (through the Southwest) for about 1500 miles with my 2012 Toyota Tacoma V6 (1GR-FE). I may just stick with the (formerly?) OEM recommended 5W-30 in synthetic, though. Depends on where the truck is on this oil change interval. Either way, I don't think anything bad will happen.
 

DaveInDenver

Expedition Leader
I think you missed a critical e, but otherwise, yep. There's a series of articles on BITOG about the value of using lower viscosity oil at startup. The author dispelled some of the thicker-is-always-better arguments. I found the series worth the time.

I'm considering 0W-40 for a specific use case where I expect high load (towing a box trailer over mountains) and high heat (through the Southwest) for about 1500 miles with my 2012 Toyota Tacoma V6 (1GR-FE). I may just stick with the (formerly?) OEM recommended 5W-30 in synthetic, though. Depends on where the truck is on this oil change interval. Either way, I don't think anything bad will happen.
I figure their recommendations and acceptable criteria are fine but since they have no skin in the game now with a warranty that has long since expired I'll follow their schedule for non-CAFE countries and continue to do periodic analysis.
 

shade

Well-known member
I figure their recommendations and acceptable criteria are fine but since they have no skin in the game now with a warranty that has long since expired I'll follow their schedule for non-CAFE countries...
Exactly. As Spart said, "It's been five years since I bought my 2014 V6, so now I am the powertrain warranty."

For light trucks & cars, are OEMs releasing Severe Service schedules any more? Doesn't seem like it. Probably a decision driven by the legal department about admitting fault or something.
 

luthj

Engineer In Residence
I doubt they would specify it for older vehicles because of federal fuel economy standards. Once a vehicle is sold, they don't matter to the OEMs. There is A LOT of engineering that goes into the bearing clearances. The engines state of tune, vehicle weight, bearing shell materials, etc. Just cause the engine number is the same, doesn't mean things haven't changed inside. Heck tighter clearances can be specified purely due to changes in thermostat temp, oil pan size, or even oil filter changes! Tighter isn't always better either!

In fact I remember one engine application, where the engine mount was moved on the block. Doing so required a looser tolerance at one bearing, because the block would distort ever so slightly under load, and it posed a binding risk.

The fact of the matter is, you trusted Toyota when they specced an oil and designed the engine, why stop trusting them now? There is no history of failures, and we lack the information to second guess the decades of experience they have at this. Its easy to think you/we have some inside information/perspective on why they did it, but the truth is we are stumbling about in the dark. Compared to true oil/bearing experts, even I have only a tiny fraction of their knowledge.
 

DaveInDenver

Expedition Leader
I doubt they would specify it for older vehicles because of federal fuel economy standards. Once a vehicle is sold, they don't matter to the OEMs.
As I understand it the CAFE law written allows manufacturers to take retroactive credit if they make a running improvement. So their current and future regulatory position can be improved. When the TSB was issued in 2006 the 1GR-FE example here could have gained them back credit for the MPG improvement on engines from 2004 and 2005.

Toyota does make changes, sometimes significant ones, to engines (many components) that share the same designation that sometimes even make them totally incompatible across years. They use production date primarily to determine this.

But the TSB and oil recommendations don't specify effectivity based on that, just generic engine designations. They have to tell you which production dates it affects to allow them to retroactively change the spec on the individual one you own regardless if they change a design or tolerances in new, ongoing production.
 
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luthj

Engineer In Residence
As I understand it the CAFE law written allows manufacturers to take retroactive credit if they make a running improvement. So their current and future regulatory position can be improved. When the TSB was issued in 2006 the 1GR-FE example here could have gained them back credit for the MPG improvement on engines from 2004 and 2005.
Thanks for the info, I just looked that up. Interesting stuff. If that is the case, it may be possible for poor decision making to come into play. Thought with some many new engines using 5w-20 oils, I don't see much cause for concern. It may be that 10+ years of service data was enough to prove that 30 weight oil was not necessary?
 

Boatbuilder79

Active member
I doubt they would specify it for older vehicles because of federal fuel economy standards. Once a vehicle is sold, they don't matter to the OEMs. There is A LOT of engineering that goes into the bearing clearances. The engines state of tune, vehicle weight, bearing shell materials, etc. Just cause the engine number is the same, doesn't mean things haven't changed inside. Heck tighter clearances can be specified purely due to changes in thermostat temp, oil pan size, or even oil filter changes! Tighter isn't always better either!

In fact I remember one engine application, where the engine mount was moved on the block. Doing so required a looser tolerance at one bearing, because the block would distort ever so slightly under load, and it posed a binding risk.

The fact of the matter is, you trusted Toyota when they specced an oil and designed the engine, why stop trusting them now? There is no history of failures, and we lack the information to second guess the decades of experience they have at this. Its easy to think you/we have some inside information/perspective on why they did it, but the truth is we are stumbling about in the dark. Compared to true oil/bearing experts, even I have only a tiny fraction of their knowledge.
That is an interesting perspective.
Your Handel says engineer in residence what does that mean exactly?
 

DaveInDenver

Expedition Leader
Thanks for the info, I just looked that up. Interesting stuff. If that is the case, it may be possible for poor decision making to come into play. Thought with some many new engines using 5w-20 oils, I don't see much cause for concern. It may be that 10+ years of service data was enough to prove that 30 weight oil was not necessary?
It's certainly possible, likely in fact, that an engine introduced a decade or so prior was highly engineered and so well manufactured that a pretty good oil then would be found that an even additionally engineered oils now would protect acceptably with new, additional benefits such as economy not found originally.

But I'm dubious that the protection of an oil is improved over the original design weight.

I approach it the same way do I with most stock things. Toyota (or whomever) gained a lot of experience and spent a lot of money designing something so it's the baseline for changes. They have a reputation (and personal experience) of high quality vehicles, so that baseline is not taken lightly. But their criteria even brand new isn't perfection, it's compromise of performance, price, regulation. If we were talking about a Porsche or Ferrari then it would be harder to argue that what they did needed to be questioned. A car like that is less constrained from the get-go to be built for performance not value. Everything Toyota does is "good enough" to work at the price they sell it. They might be slightly better (although personally I think Toyota is only average now) than other brands but it's not perfect.

I don't feel their choice of bumpers or suspension are ideal. They are fine for 90% of people but don't anticipate how I use it and so I don't feel compelled to stick with the OEM design or components. Not to mention they issue tons of TSB to repair design and manufacturing issues, several of which are very serious corrosion, safety and performance. One thing Toyota has had a history of is engine oil sludge in engines. So I see that like their frame rot, accelerator sticking, steering wheel clocking harness recalls - signs that what they built and said originally isn't the gospel.
 
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luthj

Engineer In Residence
The other question, is how many of these engines are retired due to oil related wear? I don't have any data on this. If its anything like other engine types I have done deep dives on, its other failure regimes, or the chassis wearing out that causes an engine to be retired.
 

FordGuy1

Adventurer
I can't speak for Toyota, but in regards to Ford, yes, its for fuel economy only, and yes, we see more wear. Vehicle manufactures are in the business of dong two things....Selling new cars/trucks and selling parts. If anyone thinks that any manufacture cares if your engine last 200k or 300k, you are fooling yourself. Also, If you look at component failure on vehicles that stick to 10k intervals, its way more than the 5k. We do turbos all day long, rarely do we ever replace one on customers that use good oil and service every 5k.
 

DaveInDenver

Expedition Leader
Selling new cars/trucks and selling parts. If anyone thinks that any manufacture cares if your engine last 200k or 300k, you are fooling yourself.
This is the main point. Unless a company expects you to only buy the one vehicle you can't ever assume it will last one day beyond the warranty. While they want a reputation of good cars the fact is if most people don't keep a car more than something like 100,000 miles there's no reason they should build one that lasts to 200,000. OTOH they are required (either by market demand or regulation) that the car to get good mileage from mile zero.

So it should be of no surprise to an engineering mind that those are two of your main design variables that go to fitting your curve. If Toyota has done the calculations for what it takes for the population of 1GR-FEs to hit their median and mean targets it's then my individual goal is to do whatever I can to hopefully be a right tail outlier.

In this case following their recommendations to the letter I don't think is going towards that goal. My feeling is 0W20 isn't about finding the right weight for conditions but a blanket spec that gives them the best chance to meet CAFE and its due to their ability to make good engines that they won't seize or wear out too fast.

Perhaps I'll be proved wrong in a decade but I doubt we'll ever have extensive data since the fact is most people don't keep their cars past 11 years and of the ones who do most are probably already questioning the recommendation or won't do the detailed analysis (assuming they even rebuild their own engine at all and not just slap in a reman or used one) to determine if oil weight factored into the demise of their engine.
 
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