Toyota Prius Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter · #1 ·
What brand and type of motor oil do you use in your Prius? Have you any conclusion about the superiority of one name brand an/or synthetic vs petroleoum based over another brand and type?
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #3 ·
Prius Oil

hyperion said:
There are several dozen recent threads on Prius and oil. I hesitate to mention that the 06 Honda Civic hybrid specifies 0W/20 wgt oil only to increase MPG. Combine that with a half quart low quantity and you may squeeze another couple miles per gallon.
Would mileage and performance in the Prius be enhanced by using 0W/20 or 0w/30 oil?
 

·
Registered
Joined
·
30 Posts
Oil

Haven't gotten to the first oil change yet.
when I do it'll be Mobil 1.
 

·
Registered
Joined
·
202 Posts
I've switched to Mobil1 5W-30 in my mom's Prius. I've used Mobil1 in my Honda Rebel 250 and it has gone a phenomenal over 90,000 miles without any problems, but that was 20W-50, which is definitely not what you want to put in the Prius.

However, for my Prius I've done a bit more research and I'm using Pennzoil Platinum 5W-30 in it.

Of course, both are synthetics. And unless you live close to the arctic, I think you should stay with 5W-30, not switch to 0W-20 or 0W-30, because you could be opening up a lot of questions if you ever need warranty work.

From what I've read, the Mobil1 at 30 weight is within the specifications to define 30 weight, but at the low end. The Pennzoil Platinum is supposed to be a bit higher within the specifications. But both should be fine to use. There might be some better, but those oils are harder to find.

There is a website that shows the specifications for many different weights and brands of oil, but I can't find it at the moment. Maybe somebody else would know, or when I find out I'll post it.
 

·
Registered
Joined
·
4 Posts
Synthetic Engine Oil

To Whom it may concern,

I've used Amsoil Synthetic for over 15 years in various autos and all the motorcycles I've owned with no problems or any type of grief.

To answer previous questions asked I submit the following Amsoil data:
Amsoil recomends changing engine oil at 1 year or 25,000 miles.
There is a good deal of test data available of cross country truckers that have gone over 100,00 miles with an Amsoil bi-pass filter and no oil changes.
Change the normal oil filter every six months. They recommend Amsoil filters as they are designed for extended service.
Warrentee void claims by dealers are commented on by Amsoil on their webpage and written data saying that warrentees are fully supported by auto manufactures and Amsoil itself. Along with this they state they will provide legal data and support should anyone find a dealer attempting to invalidate a warrentee based on frequency of oil changes or the use of a synthetic.
Amsoil provides much information concerning testing done by independent testers as to the performance of Amsoil versus any other synthetic or petroleum based lubricant available.

End of Amsoil data.

My independent auto service tech told me post a valve adjustment on a 1989 Honda Accord LX-I that the internals of the engine were surprisingly clean for an engine with 125,000+ miles. "It looks like new" was the quote.
Many other synthetics have value but not the long term change interval nor the type of protection under high temperature and performance demands of many engines. See Amsoil data at http://www.amsoil.com for specifics on all of their wide range of products.

The only thing I don't particularly like is that Amsoil is a network marketing organization. In their favor they do NOT use a scheme that makes only the very top rich and all other poor.

I'm on the waiting list for a 2006 Prius and will change to Amsoil after about 5,000 miles to allow for engine break-in.
 

·
Registered
Joined
·
7,161 Posts
I'd be very careful if I were you. Sure, there is a great chance that the oil and filter will stand up to Amsoil's change interval. But all they will clearly state regarding voiding manufacturer warranty is that the oil itself meets or exceeds specifications, thus will not void the warranty, but does not clearly state that extending the manufacturer's change interval won't void the warranty.

Besides, as I have been saying for quite a while, it isn't just the oil breaking down that is a problem, but combustion blowby contamination. Nobody has been able to answer to my satisfaction as to why contamination is not an issue. I understand oil breakdown perfectly, but even oil that stays brand new will get contaminated.
 

·
Registered
Joined
·
457 Posts
All of the respectable car mag articles (I've read) on conventional vs synthetic oils conclude that little if anything is gained by using the more expensive synthtics. The one exception is for exceptionally COLD weather. Synthetics don't stiffen up as much.
Radical claims of increased MPG's or performance by an oil Co. are generally made by salesmen...not engineers.
Good oil is cheap and easy to change. It doesn't breakdown..it just gets dirty.
Having said all that.. I just put 5-30 Castrol Syntec in my Prius at 10K miles. OK..so I'm a pushover for a pretty car... The Prius ICE stops and starts a lot so I figured..what the heck..
 

·
Registered
Joined
·
581 Posts
One thing about synthetics is clear; they are not based on petroleum. If we are to wean ourselves of oil-dependency, using non-fossil substitutes is another part of that effort.

Walt(falling off soapbox)
 

·
Registered
Joined
·
582 Posts
oil

After 40 k "synthetic" miles, three used oil analyses by me and more from others, and a fair bit of reading I am still trying to understand the issue. The mpg improvement seems insignif but some people in cold climates see it. Still don't know the max. "reasonable" oil change interval because I have been scared to push it beyond about 13k. Mobil 1 synthetic starts to lose its ability to neutralize combustion acids about then. The preponderance of evidence (from other engines) is that synthetic leaves the internals squeaky-clean even after many years. OTOH, conventional oil can do the same, if one changes it often enough to preclude any thermal breakdown.

With synthetics the engine simply does not release any "wear metals"; a matter which has surprised the folks who do the analyses and presumably know about those things. We simply lack Prius data whether conventional oil every 5k does as well.

If changing Prius oil on a 5k interval, it can be argued that there is little or no synthetic advantage. Obviously one is "wasting" less oil on longer change intervals, but I am not trying to convince anyone to flirt with warranty issues.

DAS
 

·
Registered
Joined
·
457 Posts
"One thing about synthetics is clear; they are not based on petroleum."
*****************************************************
That's a question I've never seen explained. Just what is synthetic oil made from/of..? It feels like petro..it smells like petro..etc...
(I've used castor oil in 2 stroke race engines and olive oil in the kitchen.)
 

·
Premium Member
Joined
·
640 Posts
I have a few questions related to this thread. I'm going for the 10,000 service on Tues. I am wondering about whether to stay with conventional oil or switch to synthetic. My neighbor was an auto mechanic and says it might not be a good idea to switch since once you go with regular oil, that by switching to synthetics and then going 10,000 mi. without an oil change, there is still regular oil mixed in with it that won't last that long and therefore can be bad for the ICE...just his personal thought. Is this a valid concern? Of course, I could change synthetics every 5,000 but that is pricey.

Also, is the warranty affected by not changing oil every 5,000 mi. with synthetics or does Toyota honor the synthetic oil recommended interval?

As to the fossil fuel issue, as I understand it, spent regular oil gets reused. And as JDavies questions, what are synthetics made from?

Lastly, a comment: I won't use Mobil 1 as I do not patronize Exxon/Mobil products.
 

·
Registered
Joined
·
269 Posts
DanMan32 said:
I'd be very careful if I were you. Sure, there is a great chance that the oil and filter will stand up to Amsoil's change interval. But all they will clearly state regarding voiding manufacturer warranty is that the oil itself meets or exceeds specifications, thus will not void the warranty, but does not clearly state that extending the manufacturer's change interval won't void the warranty.

Besides, as I have been saying for quite a while, it isn't just the oil breaking down that is a problem, but combustion blowby contamination. Nobody has been able to answer to my satisfaction as to why contamination is not an issue. I understand oil breakdown perfectly, but even oil that stays brand new will get contaminated.
Here..Here..Definitely agree with that one Dan!
 

·
Premium Member
Joined
·
2,815 Posts

·
Registered
Joined
·
582 Posts
oil

JDavies said:
... Just what is synthetic oil made from/of..? It feels like petro..it smells like petro..etc...
(I've used castor oil in 2 stroke race engines and olive oil in the kitchen.)
Most synthetic oils for internal combustion engines are poly alpha olefins. These are synthesized from ethylene which is in turn "steam cracked" from petroleum. In principle ethylene could be produced from most any hydrocarbons including plants, but at present crude oil is the cheapest starting point.

I hope this does not generally deter folks from synthetic lubricants; they do offer some clear advantages.

DAS
 

·
Registered
Joined
·
457 Posts
"at present crude oil is the cheapest starting point."
***********************************************
So.. they take a $1 qt of oil and turn it into a $4 qt of oil..??
That sure makes my weekend..
 
1 - 17 of 17 Posts
Top