Does motor oil brand make any difference for the Prius?

I downloaded a page out of a UK owners manual for the oil weights that are considered acceptable in the UK, kind of interesting they list so many weight.
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I see you are doing your homework! Nice find.

 

I wonder why they don't list 0W-40 weight. That would solve cold starting issues.

 

To me, the chart implies anything between 0w-20 and 15-40 is fair game, and of course we know that.

I'm with you on the A3/B4 0w-40's, orenji. Strong base and HTHS, low viscosity for 40 weights... Probably the best full synthetics for passenger car gas engines, **in my opinion**, especially those with a tendency toward cooked oil control rings. The oil manufacturers can keep their "high mileage", seal swellers.

 

What specific 0w-40's formulations do you like so much? I just used the Mobil-1 0w-40 "European formula" in my *other* car.

 

I believe any/all of the major brand's 0w-40's carry the A3/B4 spec, your M1 included. Your aging Gen 2 would love it, **in my opinion**. Our '07 (~180k miles) has been purring and holding steady with consumption for ~65 k miles, including some runs with A3/B4 Castrol black bottle 0w-30 and several with black bottle 0w-40. Currently filled with the Pennzoil Euro 0w-40 and runs beautifully smooth. The A3/B4's completely smooth out Gen 2 "sewing machine tick", in my experience.

Full disclosure: I don't bother with UOA's to back my feelings but member @TheChip just posted as good a Prius UOA as I've ever seen with Motul 8100 and he's autocrossing his turd gen!

Oil Analysis Results, Motul 0w-40 5k miles | PriusChat

 

VIIs also tend to form deposits when they break down. That, as well as lower "Noack" volatility (other things being equal), is why I'm taking my chances on synthetic 5W-20 instead of 0W-20.

 

Another good reason to stick to 5k miles oci with these engines...

**In my opinion**

 

Just be glad you don't have VWs. I went to the dealer to pick up oil for my TDI and they tried to hand me the wrong oil (I did the research well in advance). I'd hate to imagine what went into customers cars with all the variations VW requires.

 

For those running 0W-40: Most 0W-40 oils out there are made for BMW and Mercedes, and to meet their specifications for wear prevention, have high levels of ZDDP (around 1.5X ILSAC GF-5 oils). ZDDP is an anti-wear additive (one of the best actually). However the problem with ZDDP is that when it gets burnt (via oil coming through the PCV valve and burnt on the cylinder walls), the phosphorus in it will poison catalytic converters. The ILSAC GF-5 limits the allowable amounts of ZDDP, which is why (or at least part of the reason why) ILSAC GF-5 oil is specified in Prius' user manuals. ILSAC GF-5 oils have other anti-wear additives and provide sufficient wear protection for the engine.

So running a MB 229.5 oil for example will shorten the life of your catalytic converter, especially if you start to burn oil (which is fairly common after 150k on our engines). So I would look up the ZDDP levels in your oil and not run oils high in ZDDP. An alternative is to install an oil catch can, which will prevent some oil burning. See this for example:

https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf

To the OP: If you drive in normal conditions and change your oil at the recommended interval, then the only thing you need to think about when it comes to your oil is it being the right weight and having the right certifications. For the 3rd gen, this is 0W-20, ILSAC. However if you want to geek out on oil visit http://www.bobistheoilguy.com. There are oils out there with superior performance, but you need to pay $$$$$ for them like Amsoil and the infamous German Castrol 5w-30. For our cars, there's no reason to double the cost of an oil change for some marginal improvements.

 

So, there's no free lunch?

 

We already had our free lunch. The fact that we can run synthetic oils that are superior to oils of yesteryear in almost every way is incredible. I'm so happy to live in an age where 10,000 mile oil change intervals are possible, instead of 3-5k just a decade ago.

 

...better yet...get a Toyota Prime! But I won't go there yet...too small for me as far as cargo space and 4 seats...I guess we still have oil changes...how about a Tesla? No way...

 

Happened to have a fourth gen in front of us yesterday, driving in the morning rush hour. Seemed an odd-bird, looked diminutive/quirky somehow. They're still very rare up here.

 

I can give you my anecdotal evidence that oil brand matters, at least in my previous vehicles.

I did not do an oil analysis at the time, but before switching to Motul I noticed the Mobile One/Royal Purple I was using would cause the lifters to tick around 3k miles. After switching to Motul, I never experience that again. I've stuck with Motul 8100X-cess since then on account of the price and great reviews. The oil analysis I did on my Prius linked above indicated I was doing very well on wear. Additionally, my vehicle is a 2010, and not burning a drop of oil.

With the oil burning issue experience by a lot of our vehicles, I'm hesitant to extend my oil use past 5k miles. If the car is burning oil, would it not be better to be burning clean oil without contaminants? For the minimal cost of an oil change, I feel it's worth it for me to keep changing my oil "early" in the event it does burn some oil. Once the weather improves I'll be doing an intake manifold cleaning and installing an oil catch can to hopefully ensure the engines longevity.

I'm also not easy on my Prius. In the next year I expect to be at at least 6 two day autocross events.

 

Interesting...never heard of the Motul (before this thread) but it is expensive and sounds like it actually is "100% synthetic" which they take pains to say means it is not made with crude oil, which was the old meaning of synthetic, before the lawyers got involved.

Well as far as valve noise the question is, is it Motul or the 40W that gets you the benefit?

 

The Royal Purple and Motul I was using were always 0w40, so I assume it was because they were beginning to break down.That having been said, I did not do an oil analysis. I was driving the car very hard, doing sustained 170 MPH driving with nearly 500 horsepower, so its easy to see that could be the case. The fact that Motul didn't have the same issue gave me a lot of confidence in its quality. It's been worth it to me to pay a little bit more to get something I am feel very comfortable with using.

 

I'm surprised someone hasn't mentioned the other part of an oil change, the oil filter. I know they exist but have never really gotten into it yet.

 

Our 2010 Prius consumes some oil. I try to change it every 5K 'or so' but I leave the filter on till 10K. For the 'in between' 5K change I use my Mityvac to evacuate the oil through the dipstick. For the 10K change I do the regular oil/filter routine. BTW this system also helps in cold climates. If I time it correctly, I only need to get under the car when it is warm out!

As for oil..I'm starting to like the Penzoil Platinum line that is manufactured using natural gas. My standby is Mobil One High Mileage though. As with lots of things...it takes me quite a bit of time to 'change my religion' by switching oil brands.

 

If you watch European races, you'll see the signs.
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