In my 2.0t honda 0w-20 m1 EP viscosity @100C dropped from 8.8 to 6.5 in 3k miles, that was enough for me to switch to 5w-30. My other car that is non GDI, do not have such a big drop in viscosity, which is attributed to 5% oil dilution. So bottom line I can put 5w-30, and in few thousand miles it will look like Xw-20. If viscosity stayed close to original values, I would probably continue using 0w-20. So UOA made my decision easier to make.
Late Model Corolla 1.8L 0W20 Or Thicker OK ?
- Thread starter ChrisD46
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Problem is that most UOA's on this site are done by Blackstone, which doesn't measure fuel dilution, it's inferred from Flashpoint. And yes, there's still fuel dilution in older port injected engines, it's just typically less severe.
Since HTHS is already measured under high shear (hence, High Temperature, High Shear), viscosity loss from VII polymers permanently shearing will have a lesser effect. On the other hand, viscosity loss from fuel will be more significant.
Fuel dilution can, and does take place in port injected engines. It's just that most UOA's we share on here don't have real fuel dilution figures on them.
I mean, that's an odd tangent, but if you look at 2014, the Chrysler Town & Country, which is the SAME VAN as the Caravan, has a much lower death rate...
The Porsche Cayenne has a death rate of ZERO, followed by the Lexus GX460 at 3 and Cadillac Escalade at 6, so using your same logic, if all the people driving Odyssey's had been driving Escalade's, a lot more of those people might still be alive. Also interesting that the Toyota Sienna 4WD version has a MUCH lower death rate than the same van in FWD, same with the Ford Expedition, with the 4x4 version having a massively lower death rate than the 2WD version. Might be worthwhile to consider the variance here and what other things might be impacting these statistics beyond just design safety of the vehicle, such as cost, use by kids, income segment that owns them and looks after them...etc.
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OVERKILL
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No, they don't. I was quite sure I replied to you on this point in another thread? On top of that, these grades are RANGES, so not even within the 0W-20 grade are the oils the same viscosity at startup.
OVERKILL
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Yup, fuel dilution with certain families/brands of DI mills is wild. Honda seems to be particularly bad.
That is another concern I have about the 2018 and newer Toyotas. They use that variable prerssure electric oil pump.
I saw a video on youtube by the Toyota Master Diagnostic mechanic (The Car Care Nut) who worked for a decade in Toyota Dealers in Chicago and he has a video on the Toyota's new Dynamic Force engines.
He was trained on how these new oil pumps work. He described those new oil pumps as follows:
They stay at 10psi until about 3000 RPM's, and then they go up from 10psi to 40psi at 3000 RPMs and stay at 40psi until RPM's reach readline.
So even if you buy one of these vehicles and decide to run 0W-20 instead of 0W-16 for some added protection,
that oil pump is still going to reduce oil pressure to what it deems as adequate.
Some people say trust Toyota engineers, they know what they are doing.
But to me, using 0W-16 with HTHS=2.3 combined with an "adequate" but minimal oil pressure, might not be so great for the long term longevity of the engine.
Some may argue that because these new Dynamic Force engines are Atkinson cycle engines that the low HTHS and low but adequate oil pressure don't hurt them, but I am not so sure.
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On the Toyota oil pumps, we've previously discussed this:
https://bobistheoilguy.com/forums/t...cause-of-oil-used.358495/page-12#post-6211494
And here:
https://bobistheoilguy.com/forums/threads/toyotas-new-electric-oil-pump.355614/page-6#post-6136629
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You need to look at the 95% confidence bounds (of lowest to highest death rates) on each line, which shows the real likely range of death rates with 95% statistical certainty. A reveiw of a car for only 1 model year due to a redesign that year and having a small sample rate will have less accurate total death's and a huge range of death's in the (low, high) 95% confidence bounds parenthesis. then a vehicle with a high # of vehicles sold over a 4 year period. That is why I never look at the single # of death's, but instead look at the 95% confidence bounds in parenthesis on that same line.Problem is that most UOA's on this site are done by Blackstone, which doesn't measure fuel dilution, it's inferred from Flashpoint. And yes, there's still fuel dilution in older port injected engines, it's just typically less severe.
Since HTHS is already measured under high shear (hence, High Temperature, High Shear), viscosity loss from VII polymers permanently shearing will have a lesser effect. On the other hand, viscosity loss from fuel will be more significant.
Fuel dilution can, and does take place in port injected engines. It's just that most UOA's we share on here don't have real fuel dilution figures on them.
I mean, that's an odd tangent, but if you look at 2014, the Chrysler Town & Country, which is the SAME VAN as the Caravan, has a much lower death rate...
Might be worthwhile to consider the variance here and what other things might be impacting these statistics beyond just design safety of the vehicle, such as cost, use by kids, income segment that owns them and looks after them...etc.
Nice post about that topic of Toyota oil pumps. I'll study them.
To play Devils advocate, I’ve also heard arguments here that Honda designed their GDI such that 4-5% oil dilution is deemed normal. There are cases of people going to dealership showing their 5% fuel dilution oil analysis, the dealership did contact corporate only to be told “its normal”. I think Honda is lying about it as they have no fix for it.
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Yeah, so did you not notice:
Toyota Sienna (4WD) 0-18
Toyota Sienna (2WD) 10-31
Same van. Same year range. It's similar for the Caravan vs Chrysler T&C.
Ford Expedition (4WD) 0-36
Ford Expedition (2WD) 5-104
That's the same SUV, same year range.
As I said, I think there are other components in play, such as demographics (income brackets for example) and age. I don't recall the last time I've seen a clapped-out Odyssey or Sienna, but I probably see several clapped-out Caravan's every day.
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Yeah, it was so normal it was causing engines to stall out in cold climates and they were forced to issue a recall
They are just doing a CYA.
Only remedy is to use 5W-30 and change oil every 3k to 4k miles. Not optimal, but at least it can get the owners past a bad design.
So numbers with a wide 95% confidence range in parenthesis are less accurate due to smaller sampling size.
So in the 2014-2017 Honda Odyssey the worst it could do is 14 deaths per million registered vehicle years. The Dodge Caravan best you can get is 28 deaths and worst you can get is 54 deaths per million registered vehicle years.
My main motivation is I want my children to be safe. Don't want to buy them some frugal economy car with 100 deaths per million registered vehicle years like a Nissan.
| Vehicle | Overall death rate (with confidence limits) | Multi-vehicle crash death rate | Single-vehicle crash death rate | Rollover death rate | Model year span |
|---|---|---|---|---|---|
| Toyota Sienna 4WD | 7 (0-18) | 4 | 4 | 0 | 2014-17 |
| Honda Odyssey | 8 (2-14) | 4 | 5 | 2 | 2014-17 |
| Toyota Sienna 2WD | 20 (10-31) | 16 | 4 | 2 | 2014-17 |
| Kia Sedona | 21 (4-38) | 7 | 14 | 11 | 2015-17 |
| Chrysler Pacifica | 27 (0-58) | 21 | 5 | 0 | 2017 |
| Dodge Grand Caravan | 41 (28-54) | 26 | 15 | 5 | 2014-17 |
| All 2017 vehicles | 36 (34-37) | 22 | 13 | 5 | 2014-17 |
OVERKILL
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And that certainly applies to the Expedition 2WD (that's a really wide range) but doesn't explain the Sienna or many other examples where the vehicle is the same but the rate is very different. What does explain that is the cost of the vehicle. The 4WD models are more expensive, just like the Town & Country is more expensive than the Caravan.
Look at luxury SUV's:
Then compare the Escalade to the Yukon or Tahoe (same platform).
I understand your motivation, and I'm not dismissing your concern, I'm just pointing out that I think there's more to these numbers than one would assume at first blush and I think a significant factor is income-related.
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Yes, the Lexus GX 460 4WD looks really safe with 95% confidence bounds (0-10).
I think of it in terms of value+safety. If you can buy a 2007 Honda Odyssey for $5k on the used car market, or a new Lexus GX 460 460 4WD for $56k,
and you want to avoid a car loan due to being close to retirement age, might be better to buy the older car with low enough death rates (even if not the lowest death rate), and give the 51k difference to your child for a down payment on a house.
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OVERKILL
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The Escalade looks good too, particularly when compared to its same-platform siblings (Tahoe/Yukon):
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Also, interestingly, the GX 460 and the 4Runner share a platform, but:
And yes, I appreciate that you don't want to be in, or put your kids in vehicles perceived as death traps.
True. Toyota SUV's seem to always be safe. Maybe the Lexus has a safer and more expensive crumple zone or better air bags. I wish the same could be true of the Camry/Corolla which average out around 35 deaths even with their newest models.
The other game changer is the move to electric vehicles, where pickup trucks used to weigh 5k pounds and now with electric batteries weigh 9k pounds,
making the forces in a crash with a non electric car that much more dangerous for the lighter non electric car. Even more reason to consult the IIHS website before buying a car.
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OVERKILL
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Small cars always seem to do pretty badly.
It's also interesting to see how the safety rating "ages". Our DT RAM has a 5-star rating. The WKII (Jeep Grand Cherokee/Dodge Durango), when it was introduced, also had a 5-star rating. It no longer does, but the Durango clearly shows well in the statistics as you can see, even though the testing and the system has evolved and that platform is now "long in the tooth".
And yeah, some of the EV's are heavy, but so are the HD trucks, and they just seem to keep getting bigger.
Yes, EV's are the real threat to safety.
Sorry to have taken this thread on a tangent. Getting back to our discussion of viscosity,
It should be interesting to see how the Toyota 0W-16/0W-8 new cars with "adequate" pressue oil pumps and 10k oil changes fair over the next 15 years.
Toyota could have increased their fuel economy without going below 20 weight (HTHS=2.6) oil viscosities.
If Toyota cars break all the laws of HTHS and higher oil pressure and a high percentage of those cars make it to 200k/300k miles with little to no oil consumption in between oil changes, then I'll be impressed. But sadly I think the opposite will happen, and I'll be avoiding any Toyota >= the year 2018. Owning a car that uses an ultra low HTHS, "adequate" pressure oil pump, and recommended 10k oil changes is not something I ever want to have to deal with.
I respect those who are buying these cars and I honestly hope it works out for them.
But to me, the risk of engine wear is not worth the zero reward you get.
Sorry to have taken this thread on a tangent. Getting back to our discussion of viscosity,
It should be interesting to see how the Toyota 0W-16/0W-8 new cars with "adequate" pressue oil pumps and 10k oil changes fair over the next 15 years.
Toyota could have increased their fuel economy without going below 20 weight (HTHS=2.6) oil viscosities.
If Toyota cars break all the laws of HTHS and higher oil pressure and a high percentage of those cars make it to 200k/300k miles with little to no oil consumption in between oil changes, then I'll be impressed. But sadly I think the opposite will happen, and I'll be avoiding any Toyota >= the year 2018. Owning a car that uses an ultra low HTHS, "adequate" pressure oil pump, and recommended 10k oil changes is not something I ever want to have to deal with.
I respect those who are buying these cars and I honestly hope it works out for them.
But to me, the risk of engine wear is not worth the zero reward you get.
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