Results of switching from 5W-30 to 0W-40 in my 1GR-FE

Last year after my powertrain warranty expired, I switched from the oil recommended in the US owner's manual to 0W40.

This decision was based on a few factors. First, Toyota only recommends a singular oil weight in US vehicles. When a manufacturer certifies a vehicle for CAFE purposes in the US, they are actually not allowed to specify a heavier oil than was used for certification by the EPA.

In other countries such as Australia, Toyota continues to recommend a broad range of oil weights for the 1GR-FE and other engines all the way up to 20W-50.

20W-50 obviously isn't ideal for where I live. It gets down to -20°F in the winter quite often, with the occasional cold snap to -40°F. In the summer it gets up to 100°F routinely, and we'll occasionally see 115°F.

My oil change interval is only about every 8 months, so I don't want to run different oil in the summer and winter. Based on a bunch of research on the Bob is the Oil Guy forum I settled on 0W-40 as a good choice for my ambient temps, specifically Mobil 1 0W-40 Full Synthetic Euro Car Formula (ECF). At operating temperature it maintains very good viscosity, while also providing for excellent cold start protection.

After draining the 5W30 from my engine in June, I sent a sample off to Blackstone Labs for a Used Oil Analysis (UOA.) They use ICP spectrometry to identify, in parts per million, the metal content of oil. They also identify several other elements associated with contaminants and wear prevention additives such as Zinc. On top of this, they perform viscosity and flash point tests.

I also sent a sample of the 0W-40 I drained after changing my oil a few days ago. Both samples had approximately 5,000 miles on them.

Below you will find the results from Blackstone Labs. The first column is the 0W-40, the second column you can ignore as it's the averages for all samples, and the third column is the 5W-30.



As you can see the aluminum content dropped by 11% and the iron content dropped by 27% after switching to 0W-40.

That's all well and good, but did I incur a fuel economy hit? Not that I can tell. I have tracked my fuel economy in this truck using Fuelly since the day I bought it. The red line indicates where I changed to 0W-40.



The economy tapers off toward the end, but those are the winter months and I always get worse fuel economy in the winter because the truck gets idled more. It doesn't do as well with the winter fuel blend. I'm also past-due for an air filter change, but I didn't want to throw a variable into this test.

Subjectively, I didn't notice much other than that the engine seemed a bit quieter. This winter was milder but we did have a couple cold snaps well below 0°F, and the engine seemed to struggle a bit less turning over at those times.

Overall I'm pretty happy with my choice and at $25 for a 5qt jug, I'll continue using Mobil 1 0W-40 ECF until a better, proven choice is available on the market.

 

@Spart

Good info! Just curious, what part of the country do you live in?

 

I run my oil to 10,000 on the oil change. Your vehicle doesn't see the use mine does. I have about 104,000 on mine and run regular Mobil 1 5/30 synthetic and have since factory fill was dumped. My vehicles get pretty heavy use. My last UOA my metals are significantly less than yours at 10,300 on the used oil analysis:

Aluminum: 5
Chromium: 1
Iron: 23
Copper: 1
Tin: 0

They recommended I change the oil at 12,000 miles. I will stick with 10,000 as its easy for me to track. Thanks for sharing.

 

I thought my profile said this but I guess not, I'm in Iowa.

In addition to some occasional towing, I take lots of short trips, which means lots of cold starts. My daily commute is all of 1.6 miles! I suspect that isn't great for my engine, it's rare in the winter that I get up to operating temp by the time I get to work. My miles might not correlate to wear as well as you.

 

The short trips will contribute to oil dilution. My truck gets pretty heavy use.

 

Fellow Iowan here. Are you sure you need a 40 viscosity grade oil? My big worry about running a 0W40 motor oil (regardless of manufacturer) is that it takes something like 50% more viscosity improvers (V.I.s) to make a 10W40 than it does to make a 10W30 motor oil. (If my memory serves me correctly). I imagine the ratio would hold relatively true for the oil grades you are looking at. The V.I.s, and other additives can, and do overheat (burn) and cause varnish and deposits much more so than the base oil does. This can lead to piston rings seizing in their ring lands and other nasty things.
I know some people swear by 40 grade oils, but if it were me, I'd stick with a 5 or 10W30 grade oil IMHO. I have trusted Mobil 1 oil in all of my vehicles for more than 30 years, although I'm going to try the Amsoil Signature Series in the Taco as soon as my Toyota Care runs out.

 

Perhaps I should clarify that I'm from way down south, and I spend a lot of time in both DSM and KC.

I see a pretty good range of temps.

Regarding the varnish, I'm not sure what you're on about there. Varnish is primarily an issue with longer OCI's and conventional oil. I'm using a full synthetic with a 5000 mile OCI, and I could probably go longer but I won't.

In particular, Mobil 1 0W40 as well as other Mobil 1 full synthetics have been demonstrated to have very low varnish deposits compared to most other oils.

 

If you are using the regular Mobil 1 synthetic motor oil, it uses a hydrocracked Group III base stock. PAO or Ester based synthetic oils (Group IV and Group V) use less VIs. The quote that I have attached addresses the varnish issue I am referring to.

Quote from: http://www.upmpg.com/tech_articles/motoroil_viscosity/

Drawbacks of Viscosity Improving additives
Multi-grade motor oils perform a great service not being too thick at cold startup to prevent engine wear by providing more instantaneous oil flow to critical engine parts. However, there is a draw back. These additives shear back in high heat or during high shear force operation and break down causing some sludging. What's worse is once the additive begins to be depleted the motor oil no long resists thinning so now you have a thinner motor oil at 210 degrees. Your 10W-30 motor oil can easily become a 10W-20 or even a SAE 10 (10W-10) motor oil. I don't have to tell you why that is bad. The more VI additives the worse the problem which is why auto manufacturers decided to steer car owners away from motor oils loaded with VI additives like the 10W-40 and 20W-50 viscosities.

The less change a motor oil has from high to low temperatures gives it a high Viscosity Index. Synthetic motor oils that are made from Group IV (4) PAO base stocks have Viscosity Indexes of more than 150 because they are manufactured to be a lubricant and don't have the paraffin that causes the thickening as they cool. But petroleum based motor oils (Group I (1) & II (2)) usually have Viscosity Indexes of less than 140 because they tend to thicken more at the colder temperature due to the paraffin despite the addition of Viscosity Improving additives. The higher the Viscosity Index number the less thinning and thickening the motor oil has. In other words, high number good, low number bad. Low numbers thicken more as they cool and thin more hot. You see these Viscosity Index ratings posted on data sheets of motor oils provided by the manufacturer.

As already mentioned, VI improving additives can shear back under pressure and high heat conditions leaving the motor oil unable to protect the engine properly under high heat conditions and cause sludging. Also there is a limit to how much viscosity improving additives can be added without affecting the rest of the motor oil's chemistry. Auto manufacturers have moved away from some motor oils that require a lot of viscosity improving additives, like the 10W-40 and 20W-50 motor oils, to blends that require less viscosity additives like the 5W-20, 5W-30 and 10W-30 motor oils. Because stress loads on multi viscosity motor oils can also cause thinning many racers choose to use a straight weight petroleum racing motor oil or a PAO based Synthetic which do not have the VI additives. But only the Group IV (4) PAO based synthetics generally don't need VI additives.

(I am a retired Engineer and have no affiliation with Amsoil or any oil company.)

 

First of all I put zero stock in anything Amsoil says.

To the contrary, 0W-40 is being recommended by more and more OEMs. Most recently in my memory, Chevrolet in the Corvette.

The reason why they appear to have moved away from the higher weight oils has nothing to do with VII's and everything to do with CAFE requirements. I refer you to my earlier thread that bears this point out in detail.

Going back to M1 0W-40, check the BITOG forum and you'll find plenty of people who've cracked open engines after running on it and found virtually no varnish. I trust the real world results more than whatever Amsoil is trying to sell you on a website that looks like it was made in 1999.

 

Using Mobil 1 5/30 will be fine at 1 year 10000 miles with a normal service use. As far as varnish and wear with that interval I just replaced the valve cover gasket on my 2003 and it was like new with 218000 miles.

 

I would recommend 2 more tests to establish a reliable trend. Redline Oil makes a heavy 5W30.

 

For the record that page is not Amsoil.com and doesn't even look like an authorized page.

 

Is the giant AMSOIL banner not showing on the top for you?

 

Yes they fly a banner, but that is NOT Amsoil.com, it's "http://www.upmpg.com"

 

I suggest getting familiar with how amsoil does sales and marketing. They farm it out to a legion of "dealers" who have their own businesses, and all put up their own websites. Its not as bad now, but 15 years ago you couldn't search for anything oil without landing on an "independent amsoil dealer" page. And, it seemed ilke every forum had an amsoil dealer who would jump into any thread even tangentially related to oil and launch into an amsoil sales pitch. Seized up engine? Should have used amsoil. Bad gas milage? Try Amsoil! Wife left you? AMSOIL!!!


Yeah, I'm still not a fan of theirs.

 

Since I am an Amsoil dealer and have been for 20+ years, I can tell you that is not an Amsoil authorized web site and no way are dealers allowed to make technical proclamations about the products or make promises about MPG or even recommend products beyond what Amsoil recommends. I could have missed it but I do NOT see Amsoil authorized web site anywhere on that page. I understand the bad taste in your mouth. I assure you Al's son and son in law have been cleaning up that high pressure bullpoop. It's never been my way, I can assure you - you can check at bobistheoilguy.com . I just wanted to set the record straight. Yes dealers are allowed to have a page, like mine:

https://oilslubesandfilters.shopamsoil.com/

 

Fair enough. It has gotten better, thankfully.

As far as their site goes though, no potential customer is going to know if its a real amsoil site or not. It says amsoil on the top and they claim to be amsoil dealers on the contact page (where they also list their 4 other oil selling sites ) Guess the parent company still has some work to do.

 

I hear you. They are (now) aware.

 

OK I hear you but I constantly get 18-20 mpg maybe 17 when it's really cold with 5-30 (Toyota recommended for the 4L) and have over the last 120K. I'm not paranoid enough to test my oil I guess because my last Tacoma only had 300+K when as did the one before.