I have a 20 year old polo GTI... Still drive it spiritedly... on 160,000 miles.

Had it for 15 years...

I have always used Castrol Edge 10W40 oil but this time around the halfords & Castrol websites both say to use 5W30, 5W40 or 0W40


I still have a 4 litre bottle of 10W40 but am curious why there has been a change and what difference the alternative grades of oil would actually make?

Because of the mileage i'd stick with the 10/40

The first number is how thick the oil is cold,so 5 is thinner than 10.
So 5 offers better protection starting the engine cold as it gets around faster.
I would stick to what you've been using tbh.

I suspect oil consumption may rise using the later spec oil , think I would stick with what you have been using

I'd use what it says in the cars handbook over any website, I'd also stick with 10W/40 and the same brand

I'd stick with what VW say in the handbook myself.

On a 160,000 mile engine the tolerances will have opened up a bit so 10W/40 seems reasonable. From what I've seen it's the newer car engines that ask for 5W/xx oils (often 5W/30), probably because they're made to tighter tolerances when new.

Use what you have but there is lot of mis-information surounding oils, on an engine in good health most oil consumption is due to vapour boiling off.

Fully synthetic oils boil off very little vapour so a 5w-40 fully syntetic will give lower oil consumption than a 10w-40 semi-or 15w-40 mineral

In reality any fully synthetic oil is not fully synthetic it will contain small ammounts of mineral oil as an additive to condition the oil seals, and oils sold as mineral oil contain at least some synthetic as an additive to improve the viscosity index and the detergent qualities.
Semi-synthetic is actually vague term it really means not much.

Lately I have been using this product it is very high quality -- even the container is good quality and great vfm

MANNOL 5L Fully Synthetic Engine Oil EXTREME 5W-40 SN/CH-4 ACEA A3/B4 VW 502/505



[Edited on 15/6/20 by britishtrident]

Thanks for all the replies. Sounds fairly unanimous. I will get the same stuff I’ve always used.


Heavy oil consumption isn’t an issue at the moment thankfully. My biggest issue is body corrosion 😳🙀

I'd say corrosion's to be expected on a 20 year old steel car, once it's taken hold there's little you can do to stop it.

Project Farm YouTube channel did a whole list of videos doing rough and ready tests on US oil brands ---
Well worth watching https://www.youtube.com/playlist?list=PLjT3B9r2z3fXlvbP3tb9e056Q8O5krrCW
For anybody not owning a engine with particularly specialised lubrication requirements (which many modern PD, GDI and VVT engines have) then it shows with synthetic oils the cheapersupermarket oils are a really good buy.

For older vehicles I personally look for oils the meet BMW Longlife-04 spec.