MarkR Moderator

Very high mileage 2004 Avensis (180k miles) due an oil change. Handbook and some website site 5w/30. Local garage and motor factors seem to think 10w/40.

I've been using the 5w/30 recently, but think the 10/40 might smooth things out a bit.

I'm also debating flushing the old oil, or is that asking for trouble?

Any opinions?

kerten Registered User

If there is no oil consumption, I would stick to a known brand recommended 5/30 full synthetic.

If there is excessive oil consumption, switching to 10/40 semi synthetic may slow down oil consumption for a while but it is not a solution. Ignoring problem may cause more damage in long term.

If you switch to 10/40, I recommend shorter oil change intervals than recommended one for 5/30. Even you use 5/30, It may be a good idea to change oil more frequently than recommended interval for a high mileage engine as a general rule.

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MarkR Moderator

Oil consumption isn't that bad, think I only topped it up once or twice over the 10k miles.

I'm deciding between Castrol Magnatec 5W30 Oil 4 Litre on offer at 29.99, and Mobil Super 3000 Formula FE 5W/30 Oil 5L, full price at €38.99

Magnatec is cheaper by the litre, but I actually need a little over 6l for the service.

Will probably go for the magnatec I suppose.


Atlantic Dawn Registered User

They are doing a nice Mobil Umbrella free with 5 litres of Mobil oil in Halfords but for your situation for 6 litres I'd go with the Castrol.

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MarkR Moderator

Turns out I had 6l of Carlube 5w/30 semi synth left, so I'll use this for my service. Will try a fully synthetic one maybe next time.

Nonoperational Registered User

I think the recommended oil for these is 10W40 semi synthetic.

MarkR Moderator

Toyota book and internet geeks say 5w/30. Motor factors seem to say 10/40.

Going to go with the book for the time being.

Nonoperational Registered User

Ya good stuff, I was going by this site which I use from time to time. That's probably the information your motor factor has too but your right to go with the book.

BrianD3 Registered User

Stick with what it says in the book. TBH it surprises me when car owners don't seem to trust oil recommendations from the manufacturer of their car. And instead feel the need to consult motor factors, mechanics or internet posters - many of whom are full of sh*t and will come out with absolute garbage. Main dealers aren't immune from it either.

I have heard motor factors and mechanics recommending oil solely on the basis of the name on the tin "that Duckhams is great oil, I've been selling it for 30 years, I wouldn't touch Castrol with a bargepole!". Someone else then recommends Castrol and says Duckhams is crap. .Which one is right? Neither, they're both clueless. It's s similar story with viscosities, oil change intervals, manufacturer and ACEA ratings etc., lots of cluelessness.

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