08 Yaris burning oil. Is STP High Mileage Stop Leak safe?

[Kai_L]

Like title says. In the past, I've had good results with STP High Mileage Stop Leak on other, older models models. But I also recently learned that newer cars have variable valve timing, which means you shouldn't use oil thickening stuff like this product. 

 

In other cars, I've seen this stuff help slow down oil burn-off. I guess it makes the seals expand or something? But I don't wanna add this to my car and mess things up worse. Am I better off just adding a quart every few thousand km?

[TonyHSD]

Hi, 

It will be better not to use any additives that changes the viscosity, especially those who makes  it thicker as this can cause more trouble than help. 
If you want to try to stop any oil leak and to treat your oil seals there is better product that does not change viscosity of the oil and it’s absolutely  safe to use on any modern engine

Wynn's Engine Oil Stop Leak Sealer Treatment Additive For All Engine Types 325ml https://amzn.eu/d/fuaz7Ss

Oil burning process once started there is no other way of fixing it except mechanical repair and replace of worn out parts.
You can keep it at lower possible rate by using high quality oils , no need to change the original viscosity to thicker oils, this also does not help , can make it even worse. 
High quality engine oils that help reduce oil consumption are Shell Helix , Castrol Magnatec, GTX, Petronas syntium, check what your car manual recommends and use exactly the same type oil, I believe is A3 B4, or A5.
No need to buy fancy and expensive oils that has been made for newer cars with different modern exhaust system, egr dpf etc as these may not help in your case. 
And at the end best solution is just keep an eye and top up as necessary.
All cars after some age and mileage start burning oil and there is no way of stopping this, it’s simple physics. 👍

[bathtub tom]

I agree with Tony. a good quality oil of the correct spec. Missus had an old Minx that used to drink oil. I cadged the old oil off mates when they changed theirs. It suddenly stopped drinking the stuff and I discovered I'd got some old, used Duckham's Q or Castrol GTX. Mates had to dispose of their old oil themseves after that!

[Kai_L]

12 hours ago, TonyHSD said:

Hi, 

It will be better not to use any additives that changes the viscosity, especially those who makes  it thicker as this can cause more trouble than help. 
If you want to try to stop any oil leak and to treat your oil seals there is better product that does not change viscosity of the oil and it’s absolutely  safe to use on any modern engine

Wynn's Engine Oil Stop Leak Sealer Treatment Additive For All Engine Types 325ml https://amzn.eu/d/fuaz7Ss

 

I'll try this stuff. I'm glad I asked first before dumping some goop into my engine!

[Kai_L]

11 hours ago, bathtub tom said:

I agree with Tony. a good quality oil of the correct spec. Missus had an old Minx that used to drink oil. I cadged the old oil off mates when they changed theirs. It suddenly stopped drinking the stuff and I discovered I'd got some old, used Duckham's Q or Castrol GTX. Mates had to dispose of their old oil themseves after that!

I wonder what the shop uses. Like, when you take your car in and get a full synth oil change I wonder if that's the good stuff.

[bathtub tom]

Unless you do it yourself, you don't know if it comes out of the bulk oil tank at the back or even if you supply it, they may just think 'that'll be good for mine' and give you the bulk stuff.

Feeling in a cynical mood right now.

[TonyHSD]

Garages usually have a connection with car parts suppliers that supply engine oil too. Depends on what cars usually they service they may have a bulk of regular oil 5w30 or 5w40 and 0w20 for the newer models as these are most common these days. The brand will vary from anything like Mannol which is to be avoided imo, to Castrol or Mobile. 
If you are after a specific type of oil best to speak to them first see what they use and if you prefer your own one buy separately and ask them to use it, but you may want to watch them pouring it in to make sure it’s done indeed. 
If you go to Toyota dealer they will most likely use a Toyota branded oil, which can be anything from chevron texaco to mobile1 inside. 
At the end what is most important, regular oil and filter changes with exact oil specs as recommended by the manufacturer and regular checks and top ups. Keep the oil level at max level, but  not above. 👍