Switch to Full syntetic oil ?

I have a 2012 Prius at 110k miles. I have switched between various grades, synthetic/conventional and brands. I still don't need to top up between oil changes. I follow the Canadian oil change interval which is 8000km.

1) Mobil 1 0w20 Synthetic (last 3 winters)
2) Quaker State 5w20 Sythetic (used 1 bottle one spring)
3) Valvoline 5w20 (used a couple of bottles during the last few summers)
4) Quaker state Advanced Durability 5w20 (used a few bottles during the spring/summer/fall)
5) Pennzoil 5w30 (I put in three or 4 bottles of this too in the summer).

Right now I am back to using Mobil 1 0w20 Synthetic with the green cap for the upcoming winter. I simply ran the higher viscosity oil during the hotter seasons. I only used the other oil grades because it was left over from my previously stolen car. I had to use up my oil stockpiles.

In my opinion, the difference is marginal. The recommendation is to stay within the recommended viscosity on the oil cap which is 0w20, but I guess you can try other stuff too. My other car (non-Prius) burns oil, but I find it burns less if I simply change at shorter intervals.

 

I always use high mileage oil because it's the same price as the regular one.

I'm not sure if higher viscosities will reduce oil consumption but I once tried conventional 5w-30 and couldn't tell a difference.

 

My opinion is that using higher viscosity oil may decrease the oil consumption, but doesn’t resolve the source of the problem.

 

Oil labelled "high mileage" has additives that swell rubber/plastic. Their main use is to reduce oil consumption that's cause by leakage past rubber/plastic parts, typically valve stem guide seals. Once you start on it, it's best to stick with it: going back to regular oil there's a possibility the seals will start to shrink back, and oil consumption will increase dramatically.

I really think they should spell this out on the bottles.

 

As others have pointed out, it probably won’t hurt to club up to a slightly thicker oil (0W30) and your car is definitely high mileage.

Don’t forget to read through some of the longer oil consumption threads and keep tabs on the EGR cooler and maybe consider an oil catch can.

Good Luck!

Say “Hi” to your mayor for me the next time he’s in town.

 

Looks like the Mobil 1 "high mileage" product comes in a 5W30 and that should be better than what he is using now.
I say switch to that and stick with it.
One quart in 3000 miles really isn't that much.

How long do you intend to go between oil changes ?
I suggest that just when it needs the second quart would be good.......about 6000 miles.

 

That part of Indiana gets kinda cold in the winter, and the OP is already dealing with Lunar mileage and probably a lot or ring wear.

I’d stick with 0W......

 

This info oughta send the OP to bonkers land.

 

If there IS a lot of ring wear, there isn't much reason for the 0 weight oil at all anymore.......regardless of the temperature.

 

The high mileage oils have ingredients that cause rubber to swell. That's mainly for valve seals that have started to dry up, harden up, crack and leak. With the high mileage oil the seals may soften/swell, seal a little better, for a while. I'm not sure it would effect mpg either way, maybe slight improvement??

 

NO. Not with an engine that has over 200K miles AND is showing signs of excessive oil usage.

It is NOT a good idea to use "high mileage" oil in an engine that does not need it already.

 

High mileage oil is sort of a one-way thing: once you start using, internal rubber components swell, and if you switch back to regular oil, those rubber components can shrink, and you end up with more consumption than at the start. Bottom line: high mileage oil is a last ditch engine stretcher.