Prius and Synthetic Oil?

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53
Location
Maryland
I just got my wife a new 2010 Toyota Prius today. I haven't even gone through all the owners manuals yet. Is it OK to use synthetic oil in the Prius engine? I've used Mobil One exclusively in my prior Buick and current Acura with good results. Also how many miles is appropriate before changing from conventional to synthetic? Thanks. Steve
 
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9,427
Location
Pensacola & Vero Beach FL
 Originally Posted By: ewetho
Don't they come with like 0W-20 syn anyway???
In all honesty, I don't know about the brand new 2010 car, which has a new engine not seen before in the hybrid line. The previous Prius (04-09) never went to the 20 grade oils. In fact, when Toyota issued the TSB back-specing most of their engines to 20 wt oils, they issued another declaring that the Prius was to remain a 30 wt car. As I've said before, I suspect, but certainly can not prove, that this was because of fuel dilution issues in the 1NZ-FXE engine. I have zero knowledge of whether this will continue to be an issue with the new Prius and it's new 1.8L engine.
 
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15,385
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N.H, U.S.A.
Just DONT use Genuine Toyota motor Oil or their filters and you'll be ok. Check the manual, but I would imagine the 0w-30 M1 AFE would be a good fit. I have a batch going in* next OCI. Some guys/gals run it now and might chime in. 1.5L1NZfe yaris
 
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11,185
Location
Bad Axe, MI
 Originally Posted By: ARCOgraphite
The 0w-30 M1 AFE would be a good fit. I have a batch going in* next OCI. Some guys/gals run it now and might chime in.
I agree the AFE would work fine go for it now...
 
Messages
318
Location
Kerville, Texas
I've been a fan of synthetic oils since the 1970s. I use it in every vehicle. However, I've agonized for nine months on whether, or not, to use full synthetic oil in our 09 Cammy Hybrid. I did an O/C at 1000 miles to synthetic and now its got M1 5W-20 AFE in it at 7800 miles. At the next O/C, I'm going back to a conventional or maybe a 'blend' at 8000 miles. There's no need for full synthetic in these engines. Thanks to the BITOG-0-SPHERE; suggestions from new friends here, a chat with an oil analysis company, and some home testing, I'm convinced that either a conventional (dino) or synthetic blend is perfectly adequate. First, these engines use an Atkinson cycle. They are of very modest output and turn low rpms. (Think of them as running a generator.) They just don't develop the high sustained oil temperatures found in an Otto cycle engine. On a 100F day and a high speed run of some 65 miles, the oil temp in my HYCAM didn't get above 152F. So you don't need the high temp protection of a synthetic. IMHO, the lower oil temps mean the oil is almost always somewhere between it's "W" rating and highest viscosity rating all the time, so you need a low viscosity oil for the best flow and good MPG. Second, the engine has a mind of its own. A hybrid motor cycles on and off as it needs to. Lots of starts and lots of stops compared to a conventional set up. So there's probably a 'cold/warm start' wear issue vs. a conventional car. Here a 0W or 5W-20 would be the better choice. Again, there are plenty of conventional oils that are spec'd at 5W-20. You can get 0W-20 oils in a synthetic 'blend' if you need very low temperature protection, but they probably aren't necessary unless you are looking for slightly better MPG. As long as the oil is rated "SM" you should be just fine with a conventional 5W-20 oil or a 0W / 5W-20 blend. (Which is, oddly enough, what the manual and oil cap specify) Cheers!
 
Messages
318
Location
Kerville, Texas
 Originally Posted By: ARCOgraphite
Just DONT use Genuine Toyota motor Oil or their filters and you'll be ok. Check the manual, but I would imagine the 0w-30 M1 AFE would be a good fit. I have a batch going in* next OCI. Some guys/gals run it now and might chime in. 1.5L1NZfe yaris
I used the M1 0W-20 (not AFE) and presently 5W-20 AFE in my HYCAM. I see no difference in MPG. The biggest MPG factor ... besides the driver is ambient temperature. Cold (below 50F) and hot (over 90F)just sucks the life out of them. I see no advantage to running a 30 in these cars... see prior post.
 
Messages
318
Location
Kerville, Texas
 Originally Posted By: chevrofreak
There isn't a 5W-20 AFE. The AFE are 0W-20 and 0W-30.
Ooops! My bad! Its ZERO W - 20 AFE. Should'a known better... got two quarts on the shelf! And the Cammy has M1 5W-20 in it right now....
 
Last edited:
Messages
9,427
Location
Pensacola & Vero Beach FL
 Originally Posted By: Silber Igel
I've been a fan of synthetic oils since the 1970s. I use it in every vehicle. However, I've agonized for nine months on whether, or not, to use full synthetic oil in our 09 Cammy Hybrid. I did an O/C at 1000 miles to synthetic and now its got M1 5W-20 AFE in it at 7800 miles. At the next O/C, I'm going back to a conventional or maybe a 'blend' at 8000 miles. There's no need for full synthetic in these engines. Thanks to the BITOG-0-SPHERE; suggestions from new friends here, a chat with an oil analysis company, and some home testing, I'm convinced that either a conventional (dino) or synthetic blend is perfectly adequate. First, these engines use an Atkinson cycle. They are of very modest output and turn low rpms. (Think of them as running a generator.) They just don't develop the high sustained oil temperatures found in an Otto cycle engine. On a 100F day and a high speed run of some 65 miles, the oil temp in my HYCAM didn't get above 152F. So you don't need the high temp protection of a synthetic. IMHO, the lower oil temps mean the oil is almost always somewhere between it's "W" rating and highest viscosity rating all the time, so you need a low viscosity oil for the best flow and good MPG. Second, the engine has a mind of its own. A hybrid motor cycles on and off as it needs to. Lots of starts and lots of stops compared to a conventional set up. So there's probably a 'cold/warm start' wear issue vs. a conventional car. Here a 0W or 5W-20 would be the better choice. Again, there are plenty of conventional oils that are spec'd at 5W-20. You can get 0W-20 oils in a synthetic 'blend' if you need very low temperature protection, but they probably aren't necessary unless you are looking for slightly better MPG. As long as the oil is rated "SM" you should be just fine with a conventional 5W-20 oil or a 0W / 5W-20 blend. (Which is, oddly enough, what the manual and oil cap specify) Cheers!
Eagle: I see nothing wrong in any of that. I would only add this. But first, for perspective, I got my 09 Camry Hybrid "used" last August, with just over 5k miles on the odo. It how has over 29k on it, and I'm in the middle of an experiment in which I'm using the 12+ cSt green GC, instead of the primarily recommended 20 wt oils (remember, there's that odd language in the manual that allows the use of thicker oils). Using my laser temperature measurement device (looks like a toy handgun, sort of...), I'm consistently getting readings from 175 - 185F off the bottom of the oil pan immediately after shut down. Thus, at least in my car, I think that the oil is running hotter than the 150-160 you're seeing. Could be differences in operations, or perhaps measurement methods. At any rate, even at the temps I'm seeing, I don't think that there's any problem with the 20 wt oils. I plan to do UOAs on the presently installed GC, and the PP 0w-20 I'm going to use next. I'm expecting similar results. We'll see. For my curiosity, how are you measuring oil temps? I'd like to see if I can replicate your results.
 
Messages
318
Location
Kerville, Texas
 Originally Posted By: ekpolk
 Originally Posted By: Silber Igel
I've been a fan of synthetic oils since the 1970s. I use it in every vehicle. However, I've agonized for nine months on whether, or not, to use full synthetic oil in our 09 Cammy Hybrid. I did an O/C at 1000 miles to synthetic and now its got M1 5W-20 AFE in it at 7800 miles. At the next O/C, I'm going back to a conventional or maybe a 'blend' at 8000 miles. There's no need for full synthetic in these engines. Thanks to the BITOG-0-SPHERE; suggestions from new friends here, a chat with an oil analysis company, and some home testing, I'm convinced that either a conventional (dino) or synthetic blend is perfectly adequate. First, these engines use an Atkinson cycle. They are of very modest output and turn low rpms. (Think of them as running a generator.) They just don't develop the high sustained oil temperatures found in an Otto cycle engine. On a 100F day and a high speed run of some 65 miles, the oil temp in my HYCAM didn't get above 152F. So you don't need the high temp protection of a synthetic. IMHO, the lower oil temps mean the oil is almost always somewhere between it's "W" rating and highest viscosity rating all the time, so you need a low viscosity oil for the best flow and good MPG. Second, the engine has a mind of its own. A hybrid motor cycles on and off as it needs to. Lots of starts and lots of stops compared to a conventional set up. So there's probably a 'cold/warm start' wear issue vs. a conventional car. Here a 0W or 5W-20 would be the better choice. Again, there are plenty of conventional oils that are spec'd at 5W-20. You can get 0W-20 oils in a synthetic 'blend' if you need very low temperature protection, but they probably aren't necessary unless you are looking for slightly better MPG. As long as the oil is rated "SM" you should be just fine with a conventional 5W-20 oil or a 0W / 5W-20 blend. (Which is, oddly enough, what the manual and oil cap specify) Cheers!
Eagle: I see nothing wrong in any of that. I would only add this. But first, for perspective, I got my 09 Camry Hybrid "used" last August, with just over 5k miles on the odo. It how has over 29k on it, and I'm in the middle of an experiment in which I'm using the 12+ cSt green GC, instead of the primarily recommended 20 wt oils (remember, there's that odd language in the manual that allows the use of thicker oils). Using my laser temperature measurement device (looks like a toy handgun, sort of...), I'm consistently getting readings from 175 - 185F off the bottom of the oil pan immediately after shut down. Thus, at least in my car, I think that the oil is running hotter than the 150-160 you're seeing. Could be differences in operations, or perhaps measurement methods. At any rate, even at the temps I'm seeing, I don't think that there's any problem with the 20 wt oils. I plan to do UOAs on the presently installed GC, and the PP 0w-20 I'm going to use next. I'm expecting similar results. We'll see. For my curiosity, how are you measuring oil temps? I'd like to see if I can replicate your results.
Hi Mr. Polk ... or is it Colonel??? I take the OT reading off the tip of the dip stick as soon as I can get the hood open. I use the same IR tool. Agreed, I'd not get very worked up with OTs in this range. If you are reading the outside of the pan, you may be getting some heat reflected from the road surface to the outside of the pan.?? As you know, I'm running the 5W-20 M1right now but its due an OC about 2K miles. I'm going pull a sample and send it in for analysis for grins. Atkinson engines remind me of the old steam and oil engines that are their heritage. Efficient, big bore, short intake & long power stroke, slow RPM jobs that just thump out modest power all day long. While pondering the use of conventional or blended oil, it comes to my mind that maybe the geniuses at the TOY company designed the Atkinson engine with very low friction piston rings to improve efficiency and MPG. A syn oil or blend might not be our best choice. They may have specifically engineered the rings to seal better using a conventional SM 0W/5W-20 "dino" oil. I raise this question as my neighbor claims he's getting several more MPG (always in the low 40s) vs. mine that gets about 38 - 40 and claims not to use 'whatever the dealer puts in..." Any thoughts?? Also, the OEM oil appeared to cling to the dip stick in a sticky viscous warm 'caramel' topping manner. The syns appear to be more runny like your nose in winter. Igel (the hedgehog)
 
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15,385
Location
N.H, U.S.A.
IR tools (~Omegascope)will show different reading depending on the "emissivity" of the surface. They exhibit a not insubstantial temp reading difference from a polished steels to a anodised hardcoat Al or a flat witch-black mild St. The tool has to be calibrated to the surface finish. Alternatively, I would make a J or K type micro pill thermocouple and run it down the dip tube into the sump - or for "easy button" epoxy foil TC to the pan and run wire to the vehicle interior and install a fluke or becker via velcro(tm).
 
Messages
15,385
Location
N.H, U.S.A.
 Originally Posted By: Silber Igel
First, these engines use an Atkinson cycle. They are of very modest output and turn low rpms. (Think of them as running a generator.) They just don't develop the high sustained oil temperatures found in an Otto cycle engine. On a 100F day and a high speed run of some 65 miles, the oil temp in my HYCAM didn't get above 152F. So you don't need the high temp protection of a synthetic.
This temp reading does not make sense to me. It is certainly running hotter, at the very least w/in 5 deg of the coolant temp.
 
Messages
15,385
Location
N.H, U.S.A.
I dont think PAO oils are high temp protection - they are low temp. They may provide modest varnishing benefits vs. a grp III and maybe none. We have to talk more about varnishing. This is the big problem with toyota motors including my 1nzfe with its propensity to stick its cam chain tensioner on conventional mineral oil.
 
Messages
318
Location
Kerville, Texas
 Originally Posted By: ARCOgraphite
 Originally Posted By: Silber Igel
First, these engines use an Atkinson cycle. They are of very modest output and turn low rpms. (Think of them as running a generator.) They just don't develop the high sustained oil temperatures found in an Otto cycle engine. On a 100F day and a high speed run of some 65 miles, the oil temp in my HYCAM didn't get above 152F. So you don't need the high temp protection of a synthetic.
This temp reading does not make sense to me. It is certainly running hotter, at the very least w/in 5 deg of the coolant temp.
Its a puzzle. My Sienna's OT runs just about the same as the coolant... as you say.
 
Messages
318
Location
Kerville, Texas
 Originally Posted By: ARCOgraphite
I dont think PAO oils are high temp protection - they are low temp. They may provide modest varnishing benefits vs. a grp III and maybe none. We have to talk more about varnishing. This is the big problem with toyota motors including my 1nzfe with its propensity to stick its cam chain tensioner on conventional mineral oil.
Either oil should be OK, I think. Its the flowablity and pumpablity that is important I should think.
 
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