Can you go from synthetic back to normal oil?

I think it says you can use 5W-20 if replaced at 5k with 0W-20.

 

0w20 oil in the gen2 is fine so is the 10,000mile oil change interval. 0w20 is listed in the owners manual as the preferred choice from 2008 on although no changes were made to the specification of the engine.

Please see Toyota genuine motor oil application chart below.

 

That chart is notorious for being inaccurate; I've never seen that chart in person at a dealer - only on the internet. Stick to the 5w30 listed on the cap for your Gen 2.

 

The chart is not inaccura

The chart is not inaccurate, what evidence have you got to back up that claim? I have a hard copy from my dealer and my 2008 hand book states that 0w20 is the oil of choice. The Prius C uses the same engine and that also lists 0w20 as the preferred oil.

Many people on PC also use 0w20 in there gen2's. The Toyota oil is the best but Mobil 1 or any good quality brand should be fine. The final choice of oil grade is down to the OP but at leased lets give unbiased information.

The dealers themselves will put oil in your car that suits them, they are out to make money. How long did it take to get them to put the correct grade oil in the gen3's and even now some are still getting it wrong after 3years.

 

The Prius C's 1.5L engine has been heavily revised so it is not an apples-to-apples comparison with the Gen2.

The chart that was posted was released by Toyota Canada and not Toyota Motors Sales USA. As evident by the differences in oil change intervals and other things between the two groups, information released by Toyota Canada should not be used for Toyota USA.

Official Toyota Oil Recommendation Chart - Bob Is The Oil Guy

As far as I know, the dealers that I have been to have not seen this chart from Toyota USA.

 

I am in Europe and that chart is in use hear supplied to me by my Toyota main agent.

The only "major revision in the C engine is in it' theoretical compression ratio up from 13/1 to 13.3/1 and extra polishing of the bearings. The higher compression ratio in theory puts even greater loads on the oil and bearings.

The same basic engine used in other vehicles in Otto cycle form revs to 6500rpm the Prius rarely sees 4000rpm.

The cap on my 2008 gen2 say's ow20.

 

no, the cap is inaccurate. it only tells you the "minimally acceptable level of oil to use" and if you read the manual, it will advise of different oil blends in case of severe use, extreme cold weather, yada yada. after all, its a fricking cap!! how much detail do you want to put on there? putting the blend on there is an exercise in stupidity designed for humans to prevent them from dumping anti freeze into the hole

Toyota ORIGINALLY recommended 5,000 mile change intervals on the synthetics but changed only after a HUGE amount of questioning by Prius owners some of which backed up their questions with UOA's (used oil analysis...could be a diff acronym but you get the picture) and the fact that many other manufacturers recommended longer intervals as well

as far as substituting synthetic for regular oil, i dont know of any car that has a restriction on that. now as far as what your dealer will tell you, it all really depends on who you talk to. i had a synthetic blend (which i am running on now) put in my Prius because the synthetic stuff was not available (mostly because it was a Ford dealer and they were unaware of the synthetic oil requirement until the car showed up...) but the service person who is one of the best in the area for any dealership called Toyota and they verified that putting a syn blend in was fine but should be changed back in 5,000 miles.

 

Unfortunately what is true for you in Europe does not apply to us in the United States. There is no reason why the average joe should go do their own development testing on something that is supposed to work in theory, but there has not been official approval for.

I don't understand what you are trying to get at? The Prius manual does not list different viscosities depending on the temperature range in the manual. 5w-30 is the only approved oil for the Gen 2 Prius for the US market, regardless of what Toyota Canada and Toyota in Europe has to say. For the average driver and PriusChatter it would be silly to deviate from this recommendation.

 

OW-20 doesn't really come in a "cheap" version.

However I always recommend mobil 1 platinum or pennzoil. Both are used in NASCAR and in Indy F-1 Cars.

So should be a solid go with them and usually they aren't rediculous on price.

 

ok, i go with you. i thought the 0-20 was for -40º C and above but that is only a memory not verified

 

Wait
So you're telling me that my car only needs an oil change at 10,000 miles?
Then why does it say maintenance required before 5000 miles?
2008 prius touring with synthetic oil.. Thanks

 

The Prius engine began life in the late 90's. At that time synthetic oils were in there infancy, and not readily available. Toyota does not seem to have change the specification of the engine oil to use in the US or the oil change interval (OCI). It took Toyota some time to change the OCI on the gen3 Prius in the US from 5000 to 10,000 miles to align with there specifications for other countries. The gen2 in the UK and Europe has always had an OCI of 10,000 miles using synthetic oil. This distance for OCI's is the norm hear with most manufacturers. Some going well beyond those distances. It is also common to use 0w20 oil in the gen2 Prius, and is the oil specified from 2008 on.
Changing the oil earlier will do no harm, but it does waste oil if it is fully synthetic.

John

 

I've been changing the oil on my 2012 Prius for 2 years now. I started using 5w20 conventional oil because I had plenty of bottles left over from my last car. I still use 0w20 synthetic, but only for the colder winter months. I use a OEM oil filter. I change my oil every 8000km because that's the oil change interval in Canada.

I didn't notice any difference between the two oils. I don't see a problem switching back and forth but I would recommend keeping the oil viscosity as close to the recommended 0w20 as possible. The 10,000 mile oil change interval is probably for synthetic, so you would need to change conventional earlier.

 

OP, please remember to check your oil level on a regular basis. Just because the 0W-20 gives you a 10k interval does not mean you shouldn't check your oil level in between changes.

 

The "you cannot change from synthetic back to regular oil" story was debunked over 20 years ago. Doesn't matter, though, for your car, as you don't want (need) to go back, anyway.

 

According to the Toyota FAQ on the owners site, you still need to do 5000 mile OCI if you switch to 0w20
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This kinda defeats the point of moving to 0w20 in my opinion. If your 2008 is still under warranty, I'd recommend continuing with 5w30 and 5000 miles until warranty runs out before you experiment.

 

This thread is one of those threads that if you re-read it, it becomes funny. Hope you all see the humor as well. It also reminds me of well informed the Prius chat community is. I appreciate the knowledge base here, and the care in answering peoples questions.

 

I think the 5000 mile "service" interval is what's confusing you...

They want you to service the car every 5k (rotate tires, top off fluids) but oil change is only needed every other service aka @ 10k mile intervals..or yearly I guess if you don't do many miles..

Hope this helps.

 

True. At worst, going back to "dino oil" means any benefit you got from full synthetic is slowly lost (e.g., gum, varnish, quality of protection).

If you plan to do "extended interval" OCIs (over 5,000 miles), you want to put in the best quality of oil you can get. The higher cost easily is counterbalanced by the reduced amount of oil you use over the OCI.

Now, I knew a guy with a motorcycle that did a 1,000 mile OCI with Amsoil. I thought that was pretty stupid, but worse was that he SELLS his bike after a year or so to get a new one. He could run on peanut oil if he's not planning to keep the bike long enough for it to matter.