Toyota Service Said Don't Switch to Synthetic Oil

The Prius C engine has 0ne minor change in it's mechanical specification, the theoretical compression ratio has been increased to 13.3/1 from 13/1. This in an Otto cycle engine would put even greater stress on the bearing and oil, but doubt in the Prius it has any real affect.

 

[citation needed]

 

I have had outstanding service from PYB (Pennzoil Yellow Bottle) 5w-30 at 5k mile intervals using a Purolator filter (Results via oil analysis from Blackstone Labs). If I felt like it I'm sure it would go 8k miles without drama. I would trust the Purolator to 10k mile intervals if I went to them. No Frams, though. Not ever. Personal choice, that's all.

If you desire a change to synthetic oil, feel free at any mileage in a modern car. Any non-boutique oil you are most likely to purchase will not cause your car to be a leaker. Today's oils are a far cry from the oils of yesteryear, and require much less Gp IV oils to meet their requirements. Modern seals are less likely to be affected by modern oils. If by chance you develop a seep or weep you only have to change back to a standard oil and the problem will likely be gone within an oil change or two.

The Prius is not known as a sludge monster, so there would be no worries about busting loose a chunk of sludge to clog anything up. Likewise if you've done low-mile intervals to date. Mobil1, Pennzoil Platinum, and Pennzoil Ultra are oils well known to clean efficiently. At only 55k miles, I would not think any of these oils could find a lot of dirt, let alone produce a clogged filter. Still, you may wish to do one or two 5k mile intervals before you try for 8 or 10k mile changes...if you are worried about it. I would not be, myself. If a body were to push their oil filter to the limit, the best way to know it had reached that limit would be to check their oil analysis for insoluables. When they go up-the filter is no longer working. I recall seeing a study on an LS1 engine (I have one in my Z28). That non-Fram filter went 16k miles before it gave up the ghost.

Conventional oil vs Synthetic oil of the same viscosity will produce the same mpgs. Switching to a lower viscosity oil may increase your mpgs by some small amount that may not be discernable without very precise records.

In the end, it's your choice and it's reached for your own reasons. The above are my experience and opinions gathered from that experience. YMMV.

 

+1

If you've never done so, do some Googling about Fram oil filter construction. They're very cheaply made; mostly of paper where other manufacturers use metal and/or rubber for some internals.

Precise records? Hah! If someone pours a can of Coke in his air cleaner, drives 2 miles and sees a 10 MPG increase, there'll be a new subforum for his modification the next day!

Seriously, I've yet to see any statistical analysis done of the impact of performance modifications here. Lots and lots of seat-of-the-pants testimonials, that's about it.

 

61,000 on the odo, switched to Mobil 1 5-w-30 at 20,000 miles. No leaks, 2-3 mpg gained.

DBCassidy

 

I have a 2011 Prius.....Starting to use the oil.....
I'm use to it...I have 2 other older ones.....

Older ones (200K) are using conventional vs synthetic.....using high mileage 5W-20. Chang every 7,500 miles
using about 1 qt every 3rd-4th fill-up (1500-2000 miles)

newer one (85K) using synthetic....using 0w-20.....Change every 10,000.
now using 1 qt to every 3-4th fill-up.

Question....if I am putting "new" oil in this frequent (on going replacement), then should I be changing the oil only when the filter needs to be replaced?

if yes.....what does the conventional require.....every 10,000 miles?
.........the synthetic...15,000 miles?

thanks

 

how many quarts are you adding between changes?

 

OP's original post is such complete and utter BS from that know-nothing "tech" that I can hardly type.

I'm not even gonna read the three pages of replies, so, burn me if it's appropriate. The tech is speaking out his a@@. You can go back and forth from conventional to synthetic each oil change with no ill effects.

Other than that...I'll keep it to myself. The Toyota tech should have his wrenches cut in half and he should be thrown out of his bay.

 

After reading a few posts, I'll simply say this...

0w-20 is hard, if not impossible, to find in a non-synthetic. 5w-20 can be found as a conventional oil, but is also often synthetic. If you let people put their oil in your car you have no idea what it may actually be. If you buy your own oil and put it in, you know for sure.

The Prius C engine is built for use in every part of the world. Different parts of the world have different climes. The C is rated for every oil up to 50w, depending on the ambient temp. Use whatever is appropriate for your area. It is not DESIGNED for a thin oil. It is brow-beaten in the US to use 0w oils to give the Toyota Mothership the best corporate MPG rating possible. Singapore is able to use 50w oils...look it uip and see how your temps are similar/dissimilar.

Use whatever oil you will for your area. Follow the Toyota literature if you don't know better, and use what you wish if you do. Often, they overlap, but not always. If you use something other than 0w-20, you should know why you are able to...or you shouldn't be doing it. "Because this guy is doing it." is not good enough reason.

Caveat Emptor

 

By the way:
We are discussing under an old Gen2 thread here for a Gen3 question.
Probably better to start a new thread under Gen3.
Gen3 is 10k drain interval on synthetic. Judgement call on extending drain interval if you're adding oil a lot.

 

i AGREE ! THAT info was from a guy who doesn't even own a Prius. Don

 

Just seen this, what oil does Toyota recommend? (We have a 2006 & a 2007 both gen 2's) about 130,000 miles on each.

We'll be buying the parts in Ireland / UK.
Wonder which oil & oil filter would be best as one of the Prius's is sounding slightly like tappets in the mornings until warm up! (This car the previous owners cowboy mechanic had been getting paid for a service bang on every 10,000 & when I got it I had the old changed, it was black pretty sure he didn't service it even once in 50,000.
Since the oil change 7000 mile on the oil still looks good (although it's using oil) Gonna change the ATF too.

Ps: If I have a chance il make the previous Mechanic a nice Irish Breakfast - bacon, sausage, eggs fried with lovely black fully synthetic straight from the filter


Thanks in advance.

 

Gosh - sure wish they'd have told me that some 16 years & 100,000 miles ago

You'd think he's trying to unload his over-supply of the crap reclaimed oil he's had sitting around for some amount of years maybe.
.

 

Use the genuine Toyota oil filter - 90915-10003 if you can get it for a reasonable price. Avoid the -YZZxx filters made in Thailand as these have a different inner and would be only suitable for a 5000 mi OCI (oil change interval). If you choose a 3rd party maker, make sure it is a high mile OCI filter from a maker you know to be a producer of good/high quality product.

Originally the UK Gen II was spec'ed with 5W-30 fully synthetic on a 10,000 mile OCI, but was later updated to alternatively use 0W-20 fully synthetic. I won't give you any brand names as it may be different in your market. Just stick to a brand that you recognise as a good quality manufacturer. Try 0W-20 and if it works without increasing oil usage, stick with it. In the moderate climate here, I use 5W-30 as it is almost impossible to get 0W-20.

 

Thanks for your help