Oil viscosity

[QUOTE="

True! But, the manual recommends higher viscosity in some circumstances. For regular use, 0W-20 is certainly fine.[/QUOTE]

Then use what the manual recommends..... lol cmon man!

 

I suppose my reply was pretty pointless. I agree with you.

I'd run anything listed in the manual based on my driving style.

 

OP here. This year I ran 0W-40 all year. Where I live in Sunny CA, the winter temperatures rarely get below freezing (0*C/32*F), so I really don’t need a 0W oil. However, running a 40 weight oil in the winter is not necessary.
So, next Fall I’ll switch to 0W-20 for Winter, hopefully make up a little for our horrible winter blend gas we have to use. Then switch back to 0W-40 for Summer use sometime in the Spring.
If I lived/worked in Death Valley in the Summer, I’d be running 15W-50, or 20W-50 oil.

 

I drove through death valley last year on 0w-20. It was 115 degrees outside and we were sustained at 80mph.

My poor engine


5w-30 is a good middle ground but now I'm considering moving up to 5w-40 in the summer if I can find it.

 

Alright so roast me if ya'll need to but for summer heat over 100f should I go with
5w-30
0w-40
5w-40
10w-40
10w-50

Or is there another readily available oil I should consider?

 

I have been running 5w-30 for a year or so. I like that it takes some of the start up clatter away, and am comfortable with the 30w for the hotter days. It really just depends what your temperature variance is. My area goes from 32* to 115* but not very many 32* days so it works for me.

 

I've used 0w-40 in my 09 Tacoma for years. I just switched to 0w-40 recently in my 4Runner.

 

Lol

 

Helpful contribution thank you

 

I like that 0w40 covers all bases. You can run it year round without issue.

 

I wonder how many of these motors have succumbed to the torture of running 0w-20?

 

Under normal load/ daily driving at a reasonable temperature?

Or are you referring to the conditions that Toyota calls out in the user manual previously cited by @Thatbassguy
Toyota is pretty clear that different oils can be used when considering additional load or higher temperatures. Which many of us qualify for imo.

 

Both / either.

I guess I'm more interested in knowing the second one. Is running 0w-20 in warm weather / towing likely to cause premature failure?

 

I used the recommended 5w 20 Mobil 1 synthetic oil in my 2006 Charger RT changing it at about 10K miles for over 100K miles. The engine was mildly modified to produce 426 RWHP (just over 500 HP at the crank) I lived in Southern Indiana with many days of 90F and made countless 1/4 passes, some of them spraying up to 200 HP N2O shots. I traded the car in with 109K miles and never had any oil related issues.

https://youtu.be/T-Sbz2Etl_A?si=PzO7Uzdcvgtw4R3a

https://youtu.be/KhG0KlXEOnU?si=E9VvzaooBJRtum3c

Modern engines are built to much tighter tolerances and do not require high viscosity rated oil.

 

I'm curious honestly.

I work at an engine manufacturing plant and we see engines from many manufacturers fail within their warranty period every day. The entire company exists to rebuild these engines for the OE manufacturer. I constantly see compromises in longevity made under the guise of emissions, is this one of those compromises?

Another thing to consider is 0w-20 was spec'd for this engine to work in a wide temperature range. Think deserts of UAE, all the way to the Alaskan tundra. This oil will work in that entire temperature range, sure; but is it optimal for your region and use case?

The user manual eludes to this when saying "an oil with a higher viscosity (one with a higher value) may be better suited if the vehicle is operated at high speeds, or under extreme load conditions"

Just my two cents. For my specific use case I think 0W-40 makes the most sense.

 

Because the engine is designed to run at a specific temperature, and not vary wildly depending where you drive.

However, regarding the manual's recommendation to run a higher weight (in the second number only) in extreme conditions (desert racing, presumably), I'm wondering how to determine when you should run higher vs. just use the 20 weight.

I have a hunch that it's based on actual engine operating temp, so I'm going to check an oil viscosity chart and report back.

 

I think the 0w weight has to do with the complex VVT, which was added to wring more power out of this dog (vs. the single VVT 1GR from 4th gen). The old motor actually got better gas mileage, since it didn't open up at higher RPMs.

 

Okay, I'm feeling good about this hunch:
Under normal conditions, my 4R runs about 180 (sometimes 185), but it does creep up to around 190 when towing or doing steep grades.

I used the below chart to find the viscosity of 20 weight oil at 180, then compared 30 and 40 weights to see at what temperature they reach that viscosity. Looks like 30 weight at ~199 F is equivalent to 20 weight at 180 F, and 40 weight is the same at ~212 F. So my takeaway, is that if I'm regularly seeing above 195, that's when I'd switch to a heavier oil.

Disclosure: I'm not qualified to make a determination or give advice on what oil to use, just doing a thought experiment to interpret the OEM manual's guidance.

 

@Schlappesepple Nice. I'd be curious though what the oil temperature is when under load for a while.

The engine temperature that my scan gauge reads is coolant temp. I haven't found a code to display oil temperature (or oil pressure btw)
Obviously water temp does not equal oil temp. This is why race cars and modified cars have individual readouts for oil temp, oil pressure, water temperature, A/F ratio, EGTs, etc. Data monitoring becomes critical when pushing mechanical limitations.

 

@Schlappesepple
It is safe to say the oil temperature will be higher than the water temperature. Many reasons for this but I'll give you a personal anecdote.

My old car was a 2019 370z. It came with an oil temperature gauge from the factory. These cars were known to heat oil up when under extreme load.

On multiple track days I would see my water temperature creep up to 215-220 whilst the oil temperature was well above 240. If I continued to drive hard the water temp would remain around 220 while the oil temp would continue to climb above 250. Getting to 260 would cause the Z to go into limp mode in order to protect the engine.

Point of this story is a few hot laps would cause the 4 liters of fluid in a 3.7L N/A v6 to heat up to >250f. This would happen in a matter of minutes.

I would not be surprised if plumbing an oil temperature gauge into the 4R revealed common oil temps above 230-240 while under extreme load.

 

Thanks for the information!

How are you monitoring the temperature? Do you have a Scan Gauge (or something similar)? Or, is it displayed on the dash on the newer 4Runner? Mine just has a round temp gauge and doesn't show the actual temperature. I've considered getting a device to watch it while towing and off-roading.

 

Yeah just a scan gauge II. It won’t read oil temp or oil pressure (at least I haven’t found the correct codes to read/report this data)

Here’s an old picture of the setup.


Since this photo I’ve changed what it displays. Now I have it reporting voltage, water temp, transmission temp at converter, transmission temp at sump.

I like it. It’s a little old school but I like to see the live data. Plus it can read and clear codes when needed.

 

Something to consider is location specific oil temps. Oil temp gauges (and coolant temp for that matter) indicate the "homogeneous" or average temp. What about the specific temp at a rocker/lifter, ring/bore, or bearing/journal interface? Might specific locations see higher temps? Maybe added viscosity is cheap insurance then?

 

I think so, IF you run your 4R in what Toyota engineers call "extreme load conditions" in the manual.

The most abuse oil gets is around the piston. The oil control rings and piston are going to heat up the oil quickly. Blow-by also introduces carbon, fuel and other contaminants to your oil here. This is why oil turns black btw. Carbon and fuel contamination.

The closest thing to what your describing (that I've seen) regarding oil temp are sensors at the sump, before/ then after the oil cooler. Although typically this is racecar stuff and most builders care more about oil pressure than oil temperature.

A more common use of multiple temp sensors would be individual EGT sensors in each exhaust runner. This can allow individual cylinder fuel trimming. Which is very valuable and becoming more affordable to do.

To be clear, all this is wayy overkill for our 4Runners. I honestly would just recommend considering a 0w-30 or 0w-40 if you're in a heavy rig and feel like you might qualify for Toyota's "extreme load conditions" claim.

 

I picked 0w-40 due to running oversized tires, lower gears and heavier payload. I live in the Salt Lake area so I see a good range of temperature changes. I also take several long road trips a year. So with that mixture, I went with a thicker oil since I know it will become thinner with the increased engine temps. If I was going to choice a oil weight for a stock vehicle I drove less than 50 miles a day, I know the oil would not get up to temp and would probably run a thinner oil like a 0w-20/30.

 

My temperatures are just based off the coolant temperature, which as some you pointed out, are usually lower than the oil temps.

I have an Ultragauge unit to monitor temps, don't know if that one can pick up oil temp, but I'll see.

I'm assuming that oil temp increases 1:1 with the coolant temp, but that's probably not true. Getting a baseline oil temp, then performing the same analysis, then adding a little fudge factor (like switching to the higher oil weight at a slightly lower temp) would be safer.

Safest would be to just use the heavier oil when in doubt, at the slight cost of power loss due to added friction. I'm trying to optimize oil selection (like a good engineer), but at some point it's diminishing returns.

The way the manual is written, and common sense tells me is there's no issue running 0w-30 (or probably 40, but that's harder to find) in the normal use case. I would just stay away from the 5w-30, personally (0w to 5w seems like a much higher viscosity jump at starting temps, from the same document I used for the other comparison).

 

@Schlappesepple
If you find a code for the scan gauge to report oil temp or oil pressure please let me know. I was not able to find one.


Yes I agree 0w-30 makes the most sense if you're worried about additional load and live in an warm region.
I will be running
0w-20 in winter 15f - 70f
0w-30 in summer 70f - 120f

For reference I have 33" tires and about 450 lbs. of constant weight added. Coupled with my driving style and region I think qualifies to for Toyotas definition of "extreme load condition"

 

Plus 0W- weights are typically 100% synthetic base stock.

 

And they tend to run a little thinner than their conventional cousins do.

 

The 4Runner is sold in only North America, and the 0W20 oil is spec'd for North American conditions. More specifically, 0W20 was specified starting in the year cold-temperature operation was expanded in the EPA test cycle.

If the 4Runner were sold in Mexico, it would likely be spec'd with cheaper 5W30, with no CAFE numbers to hit. That's the case with the Tacoma - 0W20 in North America, 5W30 in Mexico.