Hi everyone. I am new to the forum and I hope that i'll get the right answers for which I thank you in advance!

I have A3 2.0 TDI 2007 with DPF which has passed 230k km. Until now I've used 5w-30 oil but once I did my last service my mechanic used Castrol edge 5w-40 with a justification that this engine has over 230k km and that a thicker oil will prolong its life.

My concern is that Castrol edge 5w-40 excludes its usage to diesels with Diesel Particulate Filter.

My question is shall I get back to a 5w-30 507 00, the right oil to use, or continue with a thicker one like 5w-40!?

 

What your mechanic is saying is good advice, normally. Thicker oil in a higher mileage motor is good advice although at 230km that's hardly what I'd call high mileage! 

Anyway, you are correct, diesels burn oil, it's in their nature. The incorrect oil can cause problem for dpfs. If it were me I would stick with the manufacturer recommended spec oil. 

Thanks for the reply Darren I will stick to 5-30.

Can you please tell me what is your opinion on high mileage, over 300k km or more?

 

I would agree with Darren, but I would ask the question, does this engine use much oil? in fact, how much oil does it use say per 1000 km? 

Perhaps I'm missing something , but I cannot see how a thicker oil will prolong engine life, when compared with keeping the oil level to normal using the correct viscosity oil.

Kind regards,

Gareth.

p.s. For what it is worth, I've been using VAG's. branded Quantum ( Longlife) oil for years in a similar mileage/ age petrol A3 throughout its life.

i think it goes back to when things used to "loosen up" causing oil leaks and oil to get past places it shouldn't and burn more oil. 

 

As magnet says. If you aren't losing significant oil between changes there is no reason not to use correct spec oil, regardless of mileage 

Thanks Gareth.

I bought this car last year (end 2015) from Switzerland with full service history and till then I did only two services.For the first one i used Mobil1 5w-30 (the recommended) and after 12k I did this second service for which my mechanic proposed to switch into a thicker one Castrol edge 5w-40 not that the engine is using oil but he just said that the 5-30 is a thin oil for this engine which has passed 230k km approx 143k miles.

When I read Castrol edge 5-40 specs it says that it excludes diesel engines with DPF, (it contains higher amount of sulfur & ash vs 5-30 and it can block DPF).

This is why I've raised this matter here and after ur advises I will definitely stick to 5-30 the recommended oil.

Thank you!

Krenar

Years ago a thicker oil was used to silence the rattle of a worn engine. If your engine has no serious wear, (which it should not have unless it's been thrashed by a boy racer,) I would stick to the manufacturer's recommended grade of oil.

Thank you Clifford, much appreciated!

the engine is in a perfect condition and Ill definitely get back to recommended oil.