WHATS THE BEST OIL? 0W20? GOOD?

I fully agree. I've never been comfortable with bulk oil from anywhere. I can be comfortable boarding an airliner because I know that the whole process is so carefully regulated and controlled that the chances of a fatal error are pretty small, if not zero. By contrast, who's there to make sure that a dealer that's having a tough month (or a supplier) doesn't fill the bulk tank with some substandard swill. I'll galdly pay a few extra bucks for retail-packaged oil to maximize my chances that I'm getting exactly what I want, and what I know is really the right thing for my engine. Better still, I almost always put it in myself.

 

Yep, what the hell is the world coming to when we have to go through all of these PITA steps??

 

ok so i ordered a 12 case of 1L/quart of 0w-20 of Toyota oil (Unfortunately they don't have the full syntheic version of this vesocity). I'm going to change my current 5w-30 full synthetic Toyota branded oil into this 12 case i got here. I will run towards the toyota recommended service interval (8000 km or 6 months) and then grab 3 quarts/liters for oil anaysis. I live in Canada so what choices do I have that do great anaysis although there were a few here on prius chat that had some interesting data stats that I surely would be interested in since my engine has 200,000 km soon and they say as the engine age you should use a higher vesocity oil. Hm so I can't reap the fuel economy benifits?

My last few oil changes I had 3000-4000 km intervals with mobil 5-30w once and toyota full synthetic 5w-30 twice before switching back to 0w-20 toyota branded oil (non-synthetic). The reason for the short intervals is because I go to work (4 km) and it hurts the oil as I abuse EV_mode with block heater combo, but on the way back I have no access to a plug so I'm force to start with a cold start for the 4 km way back (but huge hill, gets my coolant to open up the thermostat that's for sure! (83C) but poor indication if the oil is truly warmed up... so see if non syntheic can take the abuse!)

However I may have a new route soon, that involves more highway driving with some more hills covered almost 1/3 of the driving! The true test of normal toyota 0w-20 will speak for itself, as this test will debunk a lot of myths.... can't wait!!!

I will be using toyota oem filter as well!

 

Caterpillar heavy equipment dealers will sell you an oil sample test kit, called SOS.

Toromont CAT : Oil Analysis Services S·O·S

Manitoba and East, it's Toromont. In BC it's called Fining

Online Services - Self Service Applications - S.O.S. Online

If you ran this motor its entire life on a synthetic motor oil, why would you need a heavier oil? Using a quality synthetic oil means the piston ring land area, piston crown land area, should be clean. Unless you already have oil consumption issues, try the 0W-20

Do an oil analysis on the 5W-30 you're now using, to establish a baseline. You will see trends in wear metals, TBN, nitration, etc, when you compare it to the 0W-20

Contrary to popular belief, running an oil thinner that recommended will not cause a motor to instantly explode. If you run an oil thicker than recommended, especially below the rated MRV BPT, then you can expect immediate and catastrophic engine damage

For example, I run Mobil 1 0W-20 year round in my Prius with excellent used oil results, pushing 16,000 km oil/filter change intervals. With my FJ, I have better results running Mobil 1 0W-40. You will only know which viscosity and brand is appropriate by running oil analysis

 

unfortunately jayman the car has ran on bulk oil for all its life, up until 170,000 km mark is when I made the switch to synthetic (it was a taxi before but i got the service records, they always changed the oil on time at 8000 km). I don't drive my car that hard (2300 rpm is considered my "redline") so I wanted to make the switch to 0w-20 for the fuel eco boost. How much is per anaysis? since I"m a pretty cheap guy I just wanted to get away with one anaysis... hm.....

no oil consumption issues to date prius keeps all the oil!

 

Well, that might change the equation. Do a sample of the oil you're currently using, to determine if there are issues. Eg, if there is already blowby from sticking rings, the oil analysis will uncover that

Then try a run with the 0W-20, and do an analysis after that run. This will establish a baseline for comparison.

I pay $20 for the analysis. You should specifically request they check TBN, Nitration, and viscosity

 

Please see the attached Prius owner's manual from Japan.

On page 390, it shows 0W-20 is OK to use across all temperature ranges - not just in the winter.

Also, Toyota recently announced they will move to 0W-20 across the board:
FLASHPoint - 07/01/2008

 

My Universal Translator appears not to work on Japan PDF files .....

I can get the gist of the comparison scale. Its time for Synthetic, and I was not sure about 0w20. Seems its OK!

Thanks for the posting!

Pat KK6PD

 

I just switched to Toyota 0W-20 synthetic, and so far it seems to have improved my mpg ~10%, from mid-40s mpg to 50 mpg. So count me on board for this.

Since TMS USA hasn't yet approved 0W-20, those owners living in the Nevada or Arizona desert should exercise caution using this viscosity in the hot summer. Its true that the JDM owners manual shows 0W-20 covering the same range as 5W-30, but the scale stops at 40 degrees C (104 degrees F) - and since high temps in Japan are moderate, who knows how effective 0W-20 will be at 120-130 degrees F.

 

I'll stick with 5W-30 synthetic. We are coming up to strings of 40C+ days soon.

 

Wow, that's a big increase. I suspect that part of it is due to factors other than using 0W-20 rather than 5W-30 oil, but certainly some of it is, no doubt, due to the oil especially during this cold winter.

I switched to 0W-20 oil (Amsoil ASM in my case) in early November and I added grill blocking to my 2007 Prius and have much better mileage so far this winter than last. Here in New Jersey I'll be running 0W-20 year round.

Rumple

 

Well, I guess that means I'll have to try it. Since it is approved for the Prius elsewhere and in winter lower viscosity is king, I'm inclined to go lower than 5W-30 anyway.

The only time I ever had trouble with oil was at -26 F in winter...and it wasn't because it was too thin...

 

I've driven 7,000 miles on Toyota 0W-20 full synthetic oil. With the benefit of this experience I would say that I had overestimated the mpg benefit of that thinner viscosity in my post #189. Might be ~5% mpg increase although its hard to be precise given ambient temp changes over the past few months.

Normally the engine oil level will hold pretty constant between oil changes. However, with 0W-20 the engine used ~ 0.75 quart over 7K miles, during relatively mild winter weather here in southern CA. With hot summer weather approaching, I decided to go back to 5W-30 synthetic.

 

Patrick, I'm surprised by that amount of oil blowby, and I strongly suspect that your measurement is accurate. Garage floor is not spotty, right?

In a 2001 through several cycles of 0W20 my 'dipstick level' never went down.

 

Running Mobil 1 0W-20 in my 2004 Prius, in summer I couldn't detect any difference in fuel economy. In winter, perhaps 10% if the temps were -30 C and colder

However, even going 16,000 km, the oil level went down no more than 2mm. Patrick, I'm wondering if perhaps your rings/seals are already getting worn?

If you need to run a somewhat thicker oil to control oil consumption, consider Castrol Syntec 0W-30. This is rated as a "thick" xW-30. This oil has a very good reputation

 

Hi Doug, no engine oil leaks at all, engine is totally dry. Nothing on driveway where car is parked.

Here's my method of measurement: Back in January I had 4 qt of 0W-20, added 3.75 qt when filling the crankcase (since I was using the longer Toyota filter with slightly greater capacity), and then added the remaining 0.25 qt some time later when I noticed the oil level had dropped.

After draining the crankcase yesterday, I was able to fill three qt bottles with the old engine oil, filled a bit more than when the bottles contained new oil. This is the basis for my estimated 0.75 qt consumption.

Hi Jay, we'll see now that I've moved back to 5W-30. Much of the oil consumption using 0W-20 happened while on an extended road trip into AZ, driving ~75+ mph. When driving around home at more moderate speeds the oil level seemed to stabilize.

Thanks to you and Ken-san, we know that 0W-20 is approved for 2G Prius in Japan. I am wondering whether part of the reason for differing recommendations is expected driving patterns. In North America it is certainly likely that the vehicle will be taken on extended high speed runs over thousands of miles especially in hot summer weather. Maybe in Japan this doesn't happen as much.

 

Patrick

Actually, that makes a lot of sense. Driving patterns in Japan are nowhere near what they are in North America. Although it's odd that Ford's and Honda's that spec 5W-20/0W-20 don't appear to have issues

I do know that there is a lot of confusion with xW-20 vs xW-30 in some Toyota vehicles, eg the FJ Cruiser. When I ran 0W-20 in my FJ this winter, although it didn't appear to use any oil over 3,600 km, the used oil report came back with alarming nitration and oxidation.

The oil actually thickened solidly into a 30 range. I've never had any problems in that motor running 0W-40, so will probably do so. Currently running Castrol Syntec 0W-30, which is reported to be an excellent oil

Patrick, you didn't happen to sample your run with 0W-20? If the motor actually did consume oil, you would expect to see lower TBN, higher nitration and oxidation, and a spike in wear metals

jay-san

 

Hi Jay,

I did not save a sample of the used 0W-20 for testing. However in ~4 months I will change the 5W-30 and will report back whether the engine used oil or not. Also I will be taking a high speed run to Las Vegas over the weekend so this will provide an early indication if the engine is still using oil or not.

 

Yes, with the high temps now solidly in place, that high speed run should give you a good indication. If there isn't any oil use with 5W-30, I suppose it just doesn't take much ring wear to cause consumption of a lighter oil

I do know with the big industrial Waukesha V-16's, which run either a straight 40 or a 20W-40, it doesn't take much ring wear to suddenly start burning oil

 

I drove the 2004 ~800 miles so far including 540 miles round-trip to LV, after reverting to 5W-30. No noticeable oil consumption so far. High temps in LV around 100 degrees F.