UOA : 2002 Toyota Prius with 200k - OCI 6000 Miles

[macarose]

Hi there. My name is Steve Lang. A few of you may know me from The Truth About Cars. Hopefully, that's a good thing. My wife has kept a 2002 Toyota Prius for about a year and a half now. It received a new battery shortly before we bought it, and I'm more or less planning on keeping it for the forseeable future. It has recieved OCI every 6k using Castrol Syntec and a Wix filter for the last 24k. Before that it was serviced at the Toyota dealership. I am looking at extending the OCI to 9k using a P1 filter and conventional oil, or a Mobil 1 filter / EP Oil every 15k. These are the comments and the UOA results... STEVE: 200,000 miles? Please! This engine's still a spring chicken. Metals look great here, so assuming she's still running well and you're not having any problems, then there's nothing about this sample that seems troublesome at all. Averages are based on about 7,600 miles on the oil. You could run your oil a bit longer, for sure. The TBN is kind of getting low (it's down to 1.4 and 1.0 or less is low), but the TBN tends to drop more slowly the more use an oil sees, so it might hang on at this level for a while. The viscosity was fine, assuming you used a 5W/20. Try 9K miles.

Code:

MI/HR on Oil    6,200
MI/HR on Unit 200,000
Sample       04/17/14

ALUMINUM    3
CHROMIUM    0
IRON        4
COPPER      0
LEAD        0
TIN         0
MOLYBDENUM  20
NICKEL      0
MANGANESE   0
SILVER      0
TITANIUM    86
POTASSIUM   0
BORON       47
SILICON     7
SODIUM      4
CALCIUM     2224
MAGNESIUM   18
PHOSPHOROUS 685
ZINC        784
BARIUM      0

SUS Viscosity @ 210°F 53.2
cSt Viscosity @ 100°C  8.25
Flashpoint in °F     375
Fuel %       <0.5%
Antifreeze %  0.0
Water         0.0
Insoluble     0.4
TBN           1.4
  

Everything looks good from what I can see. But the Titanium is a bit high and the TBN is possibly getting to that borderline level within the next 50k miles. If any of you have any thoughts or insights, it would be very appreciated. All the best!

 

[simple_gifts]

One does not see 1st gen prii in these parts too much; I understand the engine is a variant of the engine I have in my !echo!; needless to say, 200K is about "1/2 done"

 

[FetchFar]

Iron at 4 ppm with 6200 is great! Amazing that this car stops/starts its engine every time its at a stop sign, interrupting oil pressure, and iron is still low.

 

[macarose]

Do I have anything to be concerned about with the Titanium and TBN levels? I don't think I do, but if there is a special oil/filter combination that would help extend the longevity, I'm certainly open to that idea.

 

[Garak]

Which version of Syntec are you using? The high end version uses titanium as an additive, if I recall correctly.

 

[macarose]

Strike that. It's actually a Kendall synthetic blend.

 

[walk23]

The titanium is an anti wear additive and a good thing. It is protecting your engine.

 

[buster]

Some of these Japanese engines are remarkable. Ti is part of the additive package. I would use Mobil 1 EP 0w20 or 5w20/30. You could use 5w30 without a problem. If you're looking to extend the drain intervals, a good rule of thumb is to go with a brand that has done extensive field testing with the product that is claiming extend drain capable. You could probably go 2 yrs on Mobil 1 EP or Amsoil without an issue. What I've always questioned is how are the other compoenents of the oil holding up such as seal conditioners etc.? Tbn is really a vague measurement and not the end all be all for OCI determination. Mobil 1 has historically always been very oxidation resistant over long drains and XOM has the resources to test the [censored] out of it.

 

[macarose]

My wife averages about 15k a year so I was thinking about sticking to a once a year Mobil EP / M1 Filter set-up. It may also be able to handle conventional for 9k as well. My wife does a lot of in-town driving that consists of 40 to 50 mph on one lane roads, and about 6 to 25 mile drives on average.

 

[gregk24]

Originally Posted By: FetchFar

Iron at 4 ppm with 6200 is great! Amazing that this car stops/starts its engine every time its at a stop sign, interrupting oil pressure, and iron is still low.

Chalk another one up for Japanese engineering.

 

[cptbarkey]

Originally Posted By: simple_gifts

One does not see 1st gen prii in these parts too much; I understand the engine is a variant of the engine I have in my !echo!; needless to say, 200K is about "1/2 done"

yeah if thats the case, then this thing will last to the next century.

 

[FetchFar]

Originally Posted By: gregk24

Originally Posted By: FetchFar

Iron at 4 ppm with 6200 is great! Amazing that this car stops/starts its engine every time its at a stop sign, interrupting oil pressure, and iron is still low.

Chalk another one up for Japanese engineering.

You could say Japan engineering is great, and its basically true, but remember Ford Escape Hybrids have been running for 10 years now, stopping and starting, and they last a heck of a long time, just ask NY city taxicab companies. Actually makes me re-think what I "know" about loss of oil pressure at start-up causing bearing/ring wear in excess.... hmmm

 

[FetchFar]

Originally Posted By: macarose

Strike that. It's actually a Kendall synthetic blend.

Man, that UOA looks so good, don't change oil. You've got me thinking I need Kendall with its titanium anti-wear additive package. Great UOA. Really, 4 ppm iron at 6200 miles is perfect.

 

[OneEyeJack]

It's not the start ups but the run time from cold to warm where the wear is experienced. To reduce wear during that period the Prius has a thermos that stores hot coolant and releases it back into the system as needed. The oil system is modified to support having oil pressure available and to keep some of the pressure in the system on shutdown for the next start up. It's a really clever setup. There's a lot more to the Prius that you would guess. There is no fan belt to wear out or adjust and the transmission does not shift, it's a planetary gearbox that's always engaged and there is no reverse. You backup on the main electric motor while the small one spins just enough to keep the planetary gears moving enough so the gas engine does not move. It's not a CVT and it never shifts, just one of the many reasons that a Prius is so reliable and all the complication is in the computers and software and not the mechanical parts.

 

[zerosoma]

So glad I'm a prius owner. The above post is just fantastic oneeyejack, and the results look good op!