New Motor Oil Geek: Transmission and Gear Oil Analysis at 5000 miles on Tacoma

[IDontWorkForTheWaterCo]

See.................this is what happens when you run too thick of an oil.

I had to keep looking up at the top banner to remind myself what site I was on. Literally ever oil thread on every forum reads the same

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[IDontWorkForTheWaterCo]

One thing that usually gets overlooked in the 0W-20 vs. 5W-30 debate is that OW-20 is more resistant to shearing in these close tolerance engines. That fact should account for something.

Believe it or not, engine clearances (not tolerances) have changed very little in the last 40 years or so. Some bearing surfaces have become wider to cope with lower viscosity oils, but the clearances are about the same.

What makes 0w20 have the potential to be more shear stable is the fact that it needs less friction modifiers to achieve its spread between 0w and 20. In general, the smaller the gap between the first number (W) and the second number, the more shear stable an oil is. That's why 5w20 is often sited as being very stable.

Nevertheless, that doesn't negate the fact that 5w30 will have more film strength than 0w20. And even if it falls out of grade due to shear or fuel dilution, it's likely to be at least as viscous as 0w20 in grade, maybe more.

I'm awaiting Lakespeed's info as his Tacoma continues to gain mileage. Though I currently have 0w20 in my rig, I won't hesitate to step up to 5w30 if data shows even a little benefit.

 

[BLtheP]

One thing that usually gets overlooked in the 0W-20 vs. 5W-30 debate is that OW-20 is more resistant to shearing in these close tolerance engines. That fact should account for something.

Don’t know where you came up with that but no, that is not true. First, the word you’re looking for is clearances, not tolerances. Clearances are the tight areas that the oil passes through. Tolerances are how accurately of a degree they can build the clearances to. Second, clearances have barely changed in any engines since the 70s. Clearances don’t determine oil spec, generally speaking.

 

[32spoke]

Believe it or not, engine clearances (not tolerances) have changed very little in the last 40 years or so. Some bearing surfaces have become wider to cope with lower viscosity oils, but the clearances are about the same.

What makes 0w20 have the potential to be more shear stable is the fact that it needs less friction modifiers to achieve its spread between 0w and 20. In general, the smaller the gap between the first number (W) and the second number, the more shear stable an oil is. That's why 5w20 is often sited as being very stable.

Nevertheless, that doesn't negate the fact that 5w30 will have more film strength than 0w20. And even if it falls out of grade due to shear or fuel dilution, it's likely to be at least as viscous as 0w20 in grade, maybe more.

I'm awaiting Lakespeed's info as his Tacoma continues to gain mileage. Though I currently have 0w20 in my rig, I won't hesitate to step up to 5w30 if data shows even a little benefit.

And changing the oil more often than the factory service interval would help reduce the potential an oil falling out of spec, from shearing and fuel dilution.

 

[IDontWorkForTheWaterCo]

And changing the oil more often than the factory service interval would help reduce the potential an oil falling out of spec, from shearing and fuel dilution.

100%. 6 months or 5k miles is a more reasonable approach for most people. While some folks might have little issue in the long run using a 10k interval (I have a friend's Camry that proves that), most people's driving habits and conditions lean more towads severe duty even if they don't realize it. Lot's of stop and go, idling, short tripping, delivery use, etc all wound generally fall into Toyota's severe duty schedule which cuts the time and mileage interval in half.

Also, it’s interesting that Toyota began recommending 10k intervals at about the same time Toyota Care was introduced. I'm certainly not a conspiracy theory guy, but if someone in the "chain of command" said, "10k mile oil changes will basically be ok for people", well, that literally cuts the oil change numbers in half. The bean counters certainly jumped on that. Read what you want to into that.

In 2009, Toyota introduced the 2ZR 1.8 engine for the 2010 MY. It was the first engine in N. America to recommend an LV oil (0w-20). It had a factory OCI of 5k/6 months. Shortly after that, Toyota Care dropped and that interval doubled.

 

[32spoke]

100%. 6 months or 5k miles is a more reasonable approach for most people. While some folks might have little issue in the long run using a 10k interval (I have a friend's Camry that proves that), most people's driving habits and conditions lean more towads severe duty even if they don't realize it. Lot's of stop and go, idling, short tripping, delivery use, etc all wound generally fall into Toyota's severe duty schedule which cuts the time and mileage interval in half.

Also, it’s interesting that Toyota began recommending 10k intervals at about the same time Toyota Care was introduced. I'm certainly not a conspiracy theory guy, but if someone in the "chain of command" said, "10k mile oil changes will basically be ok for people", well, that literally cuts the oil change numbers in half. The bean counters certainly jumped on that. Read what you want to into that.

In 2009, Toyota introduced the 2ZR 1.8 engine for the 2010 MY. Initially it had a factory OCI of 5k/6 months. Shortly after that, Toyota Care dropped and that interval doubled.

Oil is lubricating and engine and a turbocharger for the T24a-fts engine. Running oil change intervals out to 10k is a concern, especially if towing or hauling some weight..

 

[IDontWorkForTheWaterCo]

Oil is lubricating and engine and a turbocharger for the T24a-fts engine. Running oil change intervals out to 10k is a concern, especially if towing or hauling some weight..

I tend to agree with you. But for me, the concern is more the potential for fuel dilution. If that's an issue, then there's really just one option to mitigate it and that's a heavier weight.

 

[24tacoman]

I tend to agree with you. But for me, the concern is more the potential for fuel dilution. If that's an issue, then there's really just one option to mitigate it and that's a heavier weight.

During the winter I frequently do short trips in -35C weather where I live, but also regularly do 8 hour non stop drives. For that reason I do oil change intervals at 5000 km (3000 miles), and run 0w20 in the winter and 5w30 in the summer when it gets to +30C

 

[BLtheP]

I tend to agree with you. But for me, the concern is more the potential for fuel dilution. If that's an issue, then there's really just one option to mitigate it and that's a heavier weight.

That, plus shorter intervals to get the diluted fuel out more often. So far it seems like most of the 10k analysis samples from this truck/engine are in bad shape by then.

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