Dealership used wrong oil - 5k vs 10k?

No, just make sure it's changed with OW-16 at the next oil change. (That's what my manual for my 21 Prius says.) Did you point this out to them when you had it serviced? They should've fixed it, free, for you...it says OW-16 right on the oil fill cap!!

 

Most cars are very tolerant of being 1 or even 2 grades thicker (but not thinner) in normal weather

overseas the manual says to get the oil changed at 5k if you don’t use 0w16

so no biggie

Some here will say the dealer did you a service and 5k changes are cheap insurance

Good Luck

 

The Prius Prime called for 0W20 when it first arrived.
Has the engine physically changed since then?

 

From what I've read, yes, it's the same 1.4L engine but is now tweaked to accept the lighter OW16 oil. I have a 17 and 21 Prius and the older one takes OW20 while the new one takes OW16. I don't know what the tweaks are but assume it involves the rings and pistons.

 

I think you're just fine with 0W20. I can't really comment on the oil change interval, because I'd never let ANY weight linger in there, over 6 months or 5K miles.

 

Yes, I'm a little concerned with the lighter oil but I do oil changes every 6-months (regardless of mileage) so hoping it's not an issue. It'll be interesting to compare the different oils in the cars in the future. (I'm going to get them on the same oil-change schedule.)

 

Lower viscosity oil will give the engine less internal resistance, and, in theory anyway, should result in better gas mileage. My guess is that that's all Toyota really cares about. I mean, they lined the underbody and even gave us hubcaps to reduce wind resistance. I think they just want to be able to publish fuel economy numbers that are better than the competition, as much as possible.

I don't think the oil you have is a problem at all.

Take it from me: someone who has never changed their own oil (but I'm preparing to!!).

 

I took all 4 off and have not noticed any differences in MPG.

 

Fuel efficiency is a way of lowering carbon emissions, and the 0w16 oil was in use in Japan first. They are already testing 0w8 there.

 

I am SURE that you don't have a problem.......and never will because of that tiny difference in the oil.
Don't worry. Be happy.
It is likely that your dealer does not put 0W16 in any cars.

 

The next time have the service writer put "0W-16 oil" on the work order. Don't sign it until you see that. Then look at the oil charged to the car on the work order when you get the car back. If it says 0W-20 tell them you won't pay for the job. I'd bet that they buy the 0W-20 cheap in bulk and don't want to use the 0W-16 in more expensive small quantities. In any case there will be a sliver of fuel savings with the 0W-16.

I've taken hundreds of oil samples for analysis and reviewed the reports of the tests. Oil is good for several years in an oil sump. If anyone has doubts, one or two $30 oil analyses will let one know what's happening. That's cheaper than unneeded oil & filter changes.

As can be seen, 16 viscosity grade is very slightly lower viscosity at 100°C and 150°C than 20 VG. The main difference is a chemical difference in 16VG, and it must not be used in an engine not made for it (or tested to see that it's suitable). (xW viscosity grades are "Winter" and only get low temperate tests. 0W-x oils pass tests at -35°C and -40°C. A 0W-20 oil meets the 0W cold specs and the 20 hot specs.)

 

Maybe, maybe not. You will have NO good way to really tell.
AND.....this is certainly NOT worth making a big stink over, or even a little stink for that matter.

 

I work at a Toyota dealership in Canada, (parts dept.) and the only reason you got 0w20 is because the 0w16 is often on national backorder...

Don't worry, your Prime will live a happy life even with 0w20 in it. Much better then neglecting oil changes just to have old, soiled 0w16 oil in it anyway...

Marko!

 

The dealers over here provides full synthetics only in 0W20 and 5W40 for current year Prius models, not Prime though.
Heck, blend and mineral oils are offered too at a lower oil change interval of 5000 km.

 

When 5W20 first became the standard for Japanese 4 cylinder engines, one of my old-school friends continued to use heavier weight oils because he was convinced that extending mileage was the only concern of the Japanese engineers. The heavier weight oil had a much slower pour rate, especially in cold temps. It was the top end of his engine that suffered, camshaft, valve train, etc. - not the pistons or rings. I was surprised.

 

5W20 was second gen spec, and they've been very reliable.

FWIW, it's available in synthetic and conventional.

 

This is why I do my own oil changes. I don’t trust shops or dealers to do the right thing. Although very tempting because you don’t save a lot of money doing oil changes yourself and you have to deal with recycling the oil filter and oil. You just know that it was done right. Or may be wrong if you don’t have a mechanical ability. LOL

 

One thing that's very easy to do, and the immediate consequences are nil, is neglect to put a fresh oil filter in. I know, no one would do that, but it happens; your attention drifts, whatever. If the oil filter housing could be designed so it couldn't be installed without a filter, that'd be great.

Conversion to spin-on filter more-or-less eliminates that possibility: it's near-impossible to miss, and the consequences are immediate.