Thicker oil for higher mileage?

That idea is more applicable to older & larger engines.

That doesn't mean it has no applicability to a Prius- but first you should ask: "How fast is my Prius burning oil?"

If the car is burning a lot of oil, give something heavier a shot. If the burn rate is low or nonexistent, then there's no point at all in using heavier oil.

A few dipstick checks a few weeks apart should tell you what you need to answer these questions.

 

Old thinking actually I did this in vehicles in the '60s and '70s '70s mainly early '80s too not such good luck with that your oil burning the thicker oil is not going to slow it down very much because it thins out when it gets heat or hot anyway so it's a mild mild working crutch at best. A Band-Aid possibly. It's in an oil change cycle every 2 weeks I add about a quart 1/2 of oil to my Gen 2 which is just coming up on 300 K putting in a 40 weight doesn't slow that down at all and two week period The same amount is missing off the stick I don't see it leaking I don't see anything on the outside of the engine The soot and the tailpipe is minimal so I just have to chalk it up to age and that's that a rering the engine and putting in new bearings and all that is certainly not worth it it's very costly . The cheap oil one should be putting in now should be very inexpensive comparatively speaking and you just keep getting it that's how it's worked for me nothing's really changed in this 30 years My car's last a lot longer I wasn't getting 500,000 on KE Corollas in '71

 

I would go with Mobil 1 High Mileage oil. It comes in various weights and will swell the oil seals a bit to help reduce (not prevent) oil loss.

 

... if the oil loss is due to leaking seals. If you do have leaking seals and you start to use high mileage oil, you will never be able to go back to non-high mileage oil.

 

At 160K, 170K, and 200K there would be no reason to go back to non-high-mileage oil.

 

I don't have any leaks I haven't tried any high mileage oil doesn't seem to be any cheaper than anything else I use the semi-synthetic quite a bit there's a cost savings there and if I wanted to go back to Dino oil there's stuff's out there for a buck a quart or something two I don't know. My oil changes are generally so far out compared to others 10,000 mi etc it doesn't really become a huge issue only in the wife's car because she drives for all that weirdness so her 10,000 miles comes up in 63 74 days something like that

 

If you do not have low oil pressure at slow hot idle, then there is no benefit to using a higher viscosity oil. Only negatives as it can take longer to pump thicker oil through passages during cold starts (increasing wear), and needs more power to spin the pump.

Posted via the PriusChat mobile app.

 

I have also heard of newer engines consuming 0W oils but not 5W oils. However I haven't seen one firsthand. Our own experience is much better.

Our car has the 1NZ-FXE engine (same as yours) and its maintenance book says 0W-20, so that's what I use.

We have never seen evidence of oil consumption, now at 62k miles. I have no way of knowing if Toyota updated parts within the engine to support the use of 0W oil, or if they just tried it and Mikey liked it, so to speak.

Either way I've seen 4 years and counting of "0W is not too thin, it pays to stick to the book"

 

That's quite interesting you must have a newer Prius c because the Prius Prius from 04 or '05 to '09 my cap says 5 weight 30 My 2010s and 2013's cap says 0 20. So I'm not sure what's happening here if this is another country specification engine or what but we've run the one NZ in a few different cars Yaris included and up until 09 it was 5:30 so I'm guessing this must be a c I haven't looked under one of those I know it's the NZ engine but they may have changed the oil spec. In the dead of winter in North Carolina which is not really a winner I will run the 020 or even the 040 European engine oil because of the zero and my one NZ is really not using any excessive amounts of oil for the way it's treated

 

The W in the xW-xx notation more properly is Winter not Weight.

Your thinking on this is all wrong. If you wanted to make the difference that you think you are making you should be changing the second number, not the first. The first number denotes the viscosity of the oil when it is cold and is also relative to the ambient air temperature. You do not want to be using an oil that is thicker when cold as this could have negative impacts on engine start-up. (See mr_guy_mann post #9). So ideally you would use a 5W-30 --> 5W-40 --> 5W-50 – not that you could actually get a 5W-50. If the ambient temp is up there a 10W-40 might be appropriate, but you are talking in the 40-45ºC (104-113ºF) or hotter.

 

Castro made my 5W50 wide range synthetic oil that I used to use in one of my Corollas as usual. And yes it's the big number you want to change for the thickness not the little number. In the dead cold couple of months when it's real cold I do run the zero 30 and my Gen 2 only for like 2 months when it's well below you know 40° me and the 30s and what not it just makes pressure come up a little faster and then I'm still in the 30 weight for when I reach temperature.