Mobil 1 0w20 SM GF4 12k oci Prius 2004

[dcoyne78]

Car is driven for fuel economy, many short trips of 10-15 miles usually make weekend trips of about 100 miles round trip. Winter is finally over (we don't get very warm here until May) so the engine won't be seeing the cold startups until October. The oil is still in the engine (the sample was pulled through the dipstick) and I will report back at 14k.

A note on the makeup oil. Initially I added only about 3.25 quarts to get the oil to about halfway between the add and full marks on the dipstick. Later TeeDub pointed out that the length of an extended oci depends in part on how much oil is in the engine. For this reason I added oil to get the oil level closer to the full mark in mid- February. I had thought a half quart would bring it to full but realized that the low mark on the dipstick is 1.5 quarts below full (I had thought this was 1 quart). So the short story is I started about a half quart low, took out a half quart for 4 samples (4 oz each) which accounts for the 1 quart added so far. The engine has burned little to no oil over 12k.

Comments appreciated.

Dennis

Code:

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Blackstone Labs Oil Analyses for 2004 Prius



All samples pulled through dipstick, oil has not been changed since

Sept 2006. Will continue to analyze every 2000 miles up to one year.

Approx 53.9 mpg over 12002 miles or 222.7 gallons 87 octane

oil filter Mobil 1, air filter is OEM

Oil Type Mobil 1 0W20 SM GF4

Oil placed in service 9/26/06 at 50455 miles



Sample Date 5/4 4/3 2/11 12/23 11/13 5/4

Year of Sample 2007 2007 2007 2006 2006 2007

Makeup oil(qt)* 0.25 0.625 0.125 0 0 * added since previous UOA

Miles on Engine 62457 60465 57983 55358 52834 Univ VOA

Miles on Oil 12002 10010 7528 4903 2379 6400 0

Aluminum 4 4 4 3 2 3 0

Chromium 0 0 0 0 0 0 0

Iron 12 9 8 5 1 8 1

Copper 1 1 1 1 0 1 0

Lead 0 0 0 0 0 0 0

Tin 1 1 0 0 0 0 0

Molybdenum 100 94 88 94 91 65 93

Nickel 0 0 0 0 0 0 0

Manganese 1 0 0 0 0 1 0

Silver 0 0 0 0 0 0 0

Titanium 0 0 0 0 0 0 0

Potassium 1 1 1 0 0 1 1

Boron 43 42 40 47 51 60 74

Silicon 13 11 11 12 12 14 3

Sodium 6 6 3 5 4 7 4

Calcium 2456 2234 2210 2273 2220 2341 2080

Magnesium 16 13 12 11 11 32 13

Phosphorus 668 636 599 631 613 628 770

Zinc 806 774 700 739 720 725 871

Barium 0 0 0 0 0 0 0

Viscos SUS210F 51.9 52 51.5 53.9 52.2 53-59 54

Flashpoint (F) 370 400 370 365 370 >355 440

Fuel %
Antifreeze % 0.0 0.0 0.0 0.0 0.0 0.0

Water % 0.0 0.0 0.0 0.0 0.0
Insolubles % 0.3 0.3 0.2 0.4 0.2
TBN 3.4 4.4 4.6 2.9 8.6 9.9



TBN of 2.9 was probably in error, 4.6 result rechecked twice (4.5, 4.7)

1/8 quart (4 oz ) Mobil 1 0W20 added 1/11/2006

5/8 quart (20 oz) Mobil 1 0W20 added mid Feb 2007

1/4 quart (8 oz) Mobil 1 0w20 added 4/3/2007

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[Gary Allan]

No matter how I try ...there's no down side to this series of UOA. TBN appears to be your limit for usage. Everything is at noise level or non-existent.

The series does tend to support the loose notion that Fe is an accumulative element, while others appear to be indicating a rate of introduction to the oil. Your silicon, sodium, aluminum, and copper are pretty flat with little deviation ..while Fe climbs (as expected).

 

[dcoyne78]

Thanks Gary. I'll wait until the TBN gets to 1.9 or less to change it out or 1 year whichever comes first.

 

[TR3-2001SE]

Excellent results. This is what I have recomended to my son who has the same car.

 

[Johnny]

One observation and one question.

The neat thing about these cars is even though the mileage indicates the oil has 12K on it, it does not because the engine is not running all of the time.

Why did you choose 0W20 when Toyota calls for 5W30 in the Prius. I have a new 2007 Prius and I plan on sticking with the 5W30.

Nice report.

 

[dcoyne78]

Thanks TR3 and Johnny. I chose the 0w20 because I am a fuel economy nutcase and I read on some of the fuel economy websites (cleanmpg is my favorite) that the thinner oil would boost fuel economy somewhat and other Prius drivers had used it with success so I decided to try it at 45000 miles (I had used synthetic 5w30 before that mostly Mobil 1). At 50455 miles I started my synthetic oil life study part 2 and so far things have looked pretty good. I hope Blackstone is not missing any fuel dilution, but the wear metal numbers look ok with the Fe at 1 ppm/1000 miles. Watch for the 14000 mile report in early June.

Dennis

 

[GMorg]

On the Prius, is there a simply way to extract data for "hours-run". This type of information may be more useful than "miles" for some drivers.

 

[dcoyne78]

There is no way that I am aware of. In the winter in Maine it is pretty hard to get the engine to shut down so most of my miles so far are with the motor running (winter is pretty much November to April where I live). This problem is somewhat similar to the difference in wear between someone who cruises lightly travelled highways and someone else who sits in stop and go traffic most of the time. The engine with the highway miles will have fewer hours on the oil. If the Prius is driven mostly on the highway where it rarely shuts down, it would be similar to a conventional car. Around town in warm (60 F or higher)weather my engine probably runs only about half the time. This is the kind of driving I do about 1/2 the time so my next 8000 miles will be somewhat like 6000 on a normal car. I agree it would be nice if I had such data, but a rough approximation is the best I can do.

Dennis

 

[deven]

I think you should try Amsoil 0w20 on your next run and see if the Fe levels come down. Not that they are not great already, I am just intrigued. Great report!

 

[dcoyne78]

Thanks Deven,

I may try the Amsoil 0w20 next run, at the same time I am going to try the Amsoil EaO Oil Filter as well because I have heard that Terry recommends them highly. I also will do fewer analyses because it is kind of expensive at $30 per analysis with the TBN. Things looked quite good early on with Mobil 1 so I will probably sample at 5k and 10k and then decide from there. Another difference is that I will fill to the full mark on the dipstick from the start rather than running .75 quarts below the full mark for the first 7500 miles. I don't really think I have seen many analyses with much better than 1 ppm Fe/ 1000 miles, when there have been it is usually a shorter interval or an engine with a bypass filter. If I am at 20 ppm Fe at 20000 miles, I will be happy.

Dennis

 

[Gary Allan]

Quote:

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I agree it would be nice if I had such data, but a rough approximation is the best I can do.

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(not rereading the entire thread) I think that tracking fuel would be the most sensible method to equate engine duty cycles. When in hybrid mode ..there will be some equivalency with charge/power operation in fuel consumption ..as there will be when the engine is powering full time (albeit different numbers). If you monitor your gallons of fuel over the season(s), I think you will get a figure that shifts between two plateaus due to differing spans of mileage ..but they will probably be equal to each other in a normalized sense.

This will tend to support Ted's fuel formula for OCI.

 

[dcoyne78]

Great idea Gary! I have the mileage data and will add it to my next report in mid June. I think the gallons of fuel used over each interval is probably the number of interest, I did report the gallons of fuel used over the 12002 miles so far, for the rest of the summer my fuel economy will probably be in the mid-sixties (last summer from 5/30/06 to 9/24/06 I got 66.6 MPG over 7038 miles using 105.6 gallons of 87 octane fuel). My fuel economy for the past 12 month period has been 58 MPG, if I manage to continue at that level for the entire oci and we assume a starting TBN of 8 for the oil(TBN was 9.9 in my VOA), the OCI formula gives about 20k:
76 Hp, 91.4 cu in, 3.75 qts with filter change ,mpg=58
So we get:
OCI=80(58)(3.75)(91.4/76)=20926 miles

I got this formula from TeeDub (Ted) who said it was TooSlick's Formula for OCI. Any chance on getting a deal on the Amsoil 0w20 and an EaO Oil filter for the Prius for the next stage of the study? Has anyone run a VOA on the Amsoil 0w20 with a TBN? It would be nice to see where it starts.

Dennis