Prius 2010 Oil Change Interval Revised? Not yet... (closed)

I took my new Prius on a 3400 mile trip when it had about 2000 miles on it. I changed the oil before I went and I'm happy I did. I wanted an early oil change anyway and I didn't want to take a chance on an unknown dealership while I was traveling. Changed it again when I got home so now I'm on schedule again.

 

Capacity and Quality

Hours is another method of tracking run time. As you pointed out, it's often used when engines run at fairly constant speed or loads. This is still an estimation. Fleet operators will use the most appropriate of either miles traveled, hours of run time, or gallons of fuel burned. Fleet maintenance folks use 30mph for converting between miles and hours for on-road vehicles - even those that spend the vast majority of their time at 60 mph.

The 3000 mile oil change was actually gospel well after synthetics arrived. Synthetic base oils were built and used in road vehicles by Germany during WW2. AMSOIL and Mobil 1 had API approved synthetic engine oils in 1972 and 1974. European companies were making synthetics that met early Euro specs during the same timeframe. Oil performance standards have evolved steadily thru the years and oil quality has improved a great deal in just the last 5.

Engine oil is 75-80% 'base oil', and about 20-25% 'additive package'. The additive package is disolved in its own 'carrier oil'. The additive package does the bulk of the oil's work - like detergents, dispersants, acid neutralizers, anti-oxidents, and anti-wear.

Base oil is broken into groups. Group I and II are refined petroleum. Group III is refined petroleum that has been dewaxed and 'hydrocracked' to break longer molecule chains and saturate the molecules with hydrogen. Hydrocracking and saturation helps improve high-temperature performance; dewaxing improves low temp performance. Group IV is PAO - a synthesized hydrocarbon. Group V is 'all others' and includes things like Vasoline (strictly petroleum) and esters (a synthesized hydrocarbon).

In the US, Group I and II products are sold as 'petroleum'. Group III can be sold as 'synthetic'. PAO and ester are sold as synthetic. Group III cannot be sold as 'synthetic' outside the Americas.

Finished oil can be made from a petroleum base and a petroleum carrier, or a synthesized base and synthesized carrier, or any combination in between.

Synthetic base oil does resist oxidation and nitration better than petroleum, but both are subjected to physical damage from things like piston rings. Eventually neither oil will properly protect the engine regardless of base. Put another way - synthetic hydrocarbons are still hydrocarbons and are affected by the same laws of physics.

It's normally the additive package that dies first. Here's an example of when 3000 miles is too long:

Start with a dirty engine. Change oil and filter. During first 1000 miles, the new detergents get to work cleaning the engine. The new dispersants keep contaminants suspended in the oil. The new anti-wear components are plating on the engine surfaces. The new oil is almost 1/2 worn out, but we're only in the first third of the interval. The higher concentrations of wear metals and carbon particles increases oxidation and nitration. During the last 1000 miles of the interval, the oil is basically dead. The base oil is breaking down faster, there aren't any more detergents or dispersants to keep things clean, so deposits re-form and we're back where we started...or worse.

For a look at what happens - here's a paper comparing API SL/ACEA GF-3 and API SA (non-detergent). Once the additive package is dead, modern oil will perform nearly as poorly as the old API SA products. http://www.autoca.org/PDF/sa%20vs%20sl%20comparison%20110504%20final-rev121604.pdf

Take two oils side by side - one 100% petroleum and one 100% synthesized. Give them the appropriate additive package for a 5000 mile service interval. They'll both reach end of life at nearly the same time. There will be differences, though. The petroleum will have lost more volume due to evaporation (thicker). The petroleum will have higher rates of oxidation and nitration (thicker). The petroleum-filled engine will be dirtier and will have the lowest fuel economy for the interval. The synthetic-filled engine will have had a lower rate of wear, lower fuel burn, will be cleaner and the oil is likely to still be in the correct viscosity grade.

As another example, manufacturers have had trouble with specific engines, regardless of the type of oil used. VW/Audi had a turbocharged four in A4s and Passats that destroyed oil - synthetic was made mandatory and interval was cut in half. The main problem here is an oil cooled turbo and a 3 quart sump. Toyota/Lexus has a 2.2L 4 and a 2.7L 6 that destroys oil quickly. This is mainly from mechanical destruction - chains and gears turning even synthetic to pudding.

Here's a comparison of additive levels for three unused 0W-20 engine oils. All are marketed as synthetic. One is Group III, one is Group III/IV/V, and one is Group IV/V based. Two are designed for OEM drain intervals while one is designed for a much longer interval. Some performance gains come from the base oil, but most come from the additive package.

(physical composition)
Calcium 1733 / 2599 / 3376
Phosphorus 638 / 733 / 737
Zinc 784 / 879 / 892
Boron 200 / 99 / 17
(performance)
TBN 6.43 / 8.45 / 10.10

Based on this, one would expect the Toyota 0W-20 to give the shortest service, the Mobil 1 mid-length, and the AMSOIL to give the longest service.

Changes made from 2009 to 2010 help ensure longer drain intervals. The '09 oil capacity is 3.9 quarts while the 2010 is 4.5 qts. The 2009 specifies 5W-30 while the 2010 specifies 0W-20. Most 5W-30 sold is petroleum. 0W-20 guarantees the owner is using at least Group III oil. A lower quantity of petroleum will not last as long as a larger quantity of synthetic, even if they are formulated to perform the same side-by-side.

All oil change interval recommendations are based on time or mileage, whichever comes first.

Sorry...too long again.

Andy

 

Re: Capacity and Quality

Andy;

What a TERRIFIC and informative post, it seems evident you must be an Oil Representative of some sort!

On behalf of many Prius Chatters, I'd like to take the liberty of asking you which Synthetic Oil you would recommend for the 2010 Prius?

I understand that Toyota uses their own brand of 0w20 oil, which is NOT a true Synthetic, but rather a blend. How would you rate other brands of Synthetics for the 2010 Prius (i.e. Mobile 1, Amzoil, Castrol etc.), and due you honestly feel the Prius is a candidate for Oil Analysis?

THANKS for leting us borrow your expertees!

David (aka Blind Guy)

 

Hey, lube up, Andy dude!
Great work, slicker'n snott.
Oh, yes ... mucho Thanks!

 

Thanks Andy - so informative. I learned more about oil in 3 minutes reading your post than..., well ever.

Question - What's YOUR recommendation for timing of the FIRST oil change - before 5K under normal use?

 

Andy, good to have another oilhead onboard

 

Thanks for the good post Andy, now I have two oil experts I can get information from, you and Jayman.

I am using Mobil 1 0W20 is that a good choice for all seasons? Would there be any advantage to using say 0W30 for hot summers in the Southwest with most days over 100 degrees F?

 

Re: Capacity and Quality

Thank you David! I am an oil dealer; most of my work is commercial/fleet.

Toyota has raised the oil quality bar a fair amount by moving to 0W-20 as this all but eliminates petroleum and moves the car to a synthetic life.

It can be difficult to really 'get' the significance of that until one has experienced it. For example - my daily driver was factory-filled with a Group III 'synthetic' in 1997 and has had some flavor of synthetic in the engine and transmission most of it's life. Oil change intervals range from the standard 1 year/10,000 miles to my current 24 month average. She just turned 12 and has 392,000 miles. Yes - shifting is sloppy now and other parts have been replaced, but the engine and transmission have never been opened for repair.

The answer from a 'fleet management' perspective is to use the least expensive product that gives you the performance you want/need. After listing the goals for the car, some will choose highest fuel mileage first. Some will choose longest life. Some will choose the best product they can easily find at their closest parts store. Each choice is likely to return a different 'best oil' answer. But as a minimum, one can expect a long engine life if they stick with a synthetic GF-4 0W-20.

If one is getting free oil changes from the dealer and they know that the dealer is using Toyota's 0W-20, then I'd have no trouble suggesting they stay the course until the 'free' oil runs out. Just resist the marketing effort with each visit to the dealer - you don't need new air filters, wiper blades, and 'blinker fluid' each time you visit.

If one has to pay for the oil (my local Toyota dealer charged $7.85 for a quart) and couldn't get a discount from the dealer, I'd expect folks would move to M1. The local Wally-World charges about $6.22 a quart.

For those that drive a LOT of miles each year, it'll be very difficult to beat AMSOIL's long drain interval. But one would have to do the math and see when price per mile works in their favor.

With regard to product labeling, the definition of 'synthetic' in the US includes Group III oils derived from petroleum. A 'synthetic blend' is normally a combination of Group I and/or II petroleum with either Group III, IV, and/or ester. Most synthetics and blends on the shelf are Group III products, though one manufacturer, in an extreme of marketing BS, calls their petroleum-based products 'synthetic blend' because the additive package components are 'synthetic'...

Based on being made in the USA, the label saying "Full Synthetic", and the MSDS saying "Highly refined petroleum oil", I'm going to say that Toyota's 0W20 (if made by Nipon Oil USA) is not a blend but a Group III synthetic.

I think that any piece of equipment is a candidate for used oil analysis (UOA). UOA can let one monitor the oil in order to set a custom oil drain interval. It can also be used as a diagnostic tool - 'I'm losing anti freeze - where's it going?' Think of it like a blood test. Nobody needs one every week, but when something just doesn't feel right, an oil sample can save a lot of time and money.

My pleasure! I hope that the info helps everyone feel a LOT more comfortable about Toyota's 10,000 mile or 1 year oil change interval. Considering that the technology and expertise to blend oils capable of 1 year or 25,000 mile drain intervals has been around for more than 35 years, I think it's great to see OEMs moving into the 1970s.

Andy

 

A water cooled engine running around 190 degrees doesn't care if it's in Canada or Sierra Vista. Engine oil is tested, and specifications are listed, for 100ºC/212ºF.

The only time I might move to a 30 is if I had a full car, stuff tied to the roof, and was heading for the mountains. Toyota may say something about using 30 for extended high speed operation. In each instance, engine wear might be reduced slightly but it would cost fuel efficiency - and the expense of another oil and filter change.

With the CVT keeping the engine from lugging, and the boost from the electrics, it's probably not necessary to change.

 

OK.. I don't want to make your head explode Andy... but you've just qualified this thread to become a sticky IMO! Welcome to the Forum!

Not only is this extremely interesting, its quite valuable information!
Bringing this much understanding to what makes oil tick sheds a ton of light on other issues.
Its a pleasure to have another professional in the field that actually knows what he's talking about.... of course if you don't, I wouldn't know any better! LOL!

Thanks for taking the time to place your input.

BTW... do you have any input on the claim that Castrol "Edge" outperforms Mobil 1 "times 8"?

Not sure if they even make it in 0W-20W but wondering if Castrol in general is a better synthetic to choose?

 

OK, Alan, now we're going to find out whether he's also had legal training.

Regardless of how much I knew about oil, I know my response would begin with: "It depends." I might start: "Good question, Alan; and the answer depends on . . ."

Of course, an awful lot of engineers are going to have the same approach, noting the different uses for the oils and the type of load placed on the engine . . ..

If he's pretty smart, though, he'll probably start with: "Which side did your brother-in-law take on this question, Alan; and how much money did you bet on it?"

 

Your right.. I was wondering why the original question about which one to buy was never answered!

Humm... lets see.. we have to word this another way...

Let me rephrase the question since the prosecution has thrown out the original question.....

Andy, what oil do you put in your Prius?

So far, it sounds like as long as we stick with a true Group III synthetic, we're good.

[ame="http://en.wikipedia.org/wiki/Synthetic_oil"]This[/ame] is good reading too.

This may explain Andy's opinion on Amsoil

I guess when oil changes are more than twice as long as its competitors, price is justified and maybe even cheaper?

This indeed impressive...

 

I ran Mobil 1 0W-20 for most of the time I had my 2004 Prius, including summer trips to Rochester MN in hot weather. Based on UOA, it worked very well.

So, I wouldn't worry about running 0W-20 year round in a 2010 Prius. Once we get a few UOA's in, the answer will be more concrete

 

I think that pretty well sums it up!

I've seen more than one post by a PCer who has really liked Amsoil. It is great that you get a one year/25,000 mile OCI, but how many people put 25,000 miles on their cars in one year. I've had my car just under 4 months, and I have only 7,400 miles on it. At this pace, I'd have only . . . ooops. Maybe I should be looking into this Amsoil!

 

Thanks very much gentlemen. Sorry for the side-step. Vendor neutral.

My goal is to provide info that helps an owner feel comfortable when they pull five quarts of oil off the store shelf. There are plenty of 0W20 options that carry the required ILSAC GF-4 quality level. At least one of the options says it's part synthetic (a BP/Castrol product); the rest appear to be synthetic.

Oil companies have to conduct performance testing to ensure their products meet the minimum requirements, but they don't have to share the results with us. Sometimes the info their marketing folks use isn't quite correct. Sometimes they get caught, sometimes they don't.

Let's look at the Edge claim. Their website says it's based on 8 times better wear protection in the Sequence IVA test. This test is required for both ILSAC GF-4 and API SM. It's a single test designed to make sure the oil will adequately protect cam lobes from wear. Most parts in an engine are separated by an oil film, but the film is thinnest on the camshaft at 0-1 micron (thousandth of a mm). The test evaluates the effectiveness of the oil's anti wear additive(s). As reported in Jobbers World May '09, this isn't the first time a company has tried to use a statistically insignificant number to claim superiority. Seems Jimmy isn't the only one that needs to get whacked...

Bottom line - use a synthetic GF-4 0W-20 and be one of the 7% of Americans that benefit from the better fuel economy, cleaner emissions and longer engine life that synthetic oil brings.

Andy

 

I have two 2006 prius's and both have 91K on them divided by 3.5 years..... I pretty much qualify... besides it will be nice to only change oil once a year!.....
I wonder if the oil filter will suffice that long?...... sure it will if its an Amsoil oil filter but what about other brands?
The Amsoil site didn't have have 2010 Prius on thier oil filter list that I could find... besides, I've already bought a box of 10 from another vendor.

 

thanks a bunch Andy, you said all you need to say and answered everything well.... I appreciate it.

I looked at the pdf's you linked and wasn't sure what I was seeing.

Do I understand the GF-4 to be a better grade than Group III?
I don't know what the "GF" stands for unless its "group something?

And then I read the Amsoil ad and it says its Group IV.... does that put amsoil above or equal to GF-4?.....

Sorry I'm such a newbie to these terms.

 

I'm not looking for a recommendation, here, but I'm wondering why the Genuine Toyota 0W-20 is rated SM, while the ExxonMobil Mobil 1 0W-20 is rated SM/CF. Is there any real difference betwen them (I know both have the ILSAC GF-4 quality rating)?

 

Hey, a priori,

I'm just guessing here, but I think the "CF" is just the current oil classification for diesel motor applications. I remember back in the mid 70's when specification SC & SD were the currect ones for new cars with gasoline engines, my Peugeot owners manual for the diesel required one of the "D" classifications [I think they were DL (diesel light duty),DM (diesel moderate duty), & DS (diesel severe duty)]. After a while I couldn't find any quart cans with one of the "D" markings on it, so I called Castrol (the brand I was using then). They told me to start looking for cans with "CC" on the lids as that was going to be the new spec for all diesel use. So I'm guessing that the way SC & SD progressed all through the alphabet to the current SM, that CC has only made its way up to the CF that you're asking about.

So, I would say that either oil (the Toyota one or the Exxon/Mobil one) will be fine for your Prius. But if you had a diesel car also in your driveway, use only the Exxon/Mobil (or any other brand) with the "CF" on it for the diesel.

Ken (in Bolton,Ct)

 

Sorry. The GF-4 refers to a performance specification.

There are a number of worldwide groups that develop and manage engine oil performance specifications.

The European Automobile Manufacturers Association (ACEA) manages the European specs. Ax for gasoline, Bx for diesel cars, Cx for advanced emissions catalyst engines, and Ex for diesel trucks.

GM, Ford, and Chrysler products sold in the Americas are covered by the American Petroleum Institute (API) specifications. The current API specs for spark-ignition engines are SJ, SL, and SM. Cx specs are for compression-ignition (diesel) engines.

The Japanese Auto Manufacturers Association and the API coordinate joint oil specs under the International Lubricant Standardization and Approval Committee (ILSAC). Current ILSAC performance levels are GF-3 and GF-4.

The base oil and additives are like different Legos that are combined to create a fluid that can pass all the tests required for a specific performance specification.

Some products carry multiple performance ratings. The Toyota bottle only lists API SM, but I believe that API SM and ILSAC GF-4 use the same tests and test limits, so would expect this oil to automatically carry both ratings.

CF is an older but still current diesel spec. Performance is met with SM testing, so many products also carry CF.

Manufacturers sometimes have their own specifications when they want a product to have better performance in specific areas or to work around an engineering challenge. Some commonly seen examples are Ford's WSS-M2C930-A and Chrysler's MS-6395.