Carlube semi synthetic 10W40

General Discussion Forums Car Talk
21

Just Checked the Castrol site and it recommended 5W40 Synthetic or 10W40 semi synthetic for the MKI 1600 engine I have, they do not show 5W30 as a recommended option for that engine but  I guess you can get away with it.

http://www.castrol.com/castrol/sectionbodycopy.do?categoryId=9024084&contentId=7073092

 

22

 

Rich, sorry I’m still confused at the remark you made below.

 

The original poster asked about a carlube semi synthetic oil and you said “could perhaps be improved on at a cost”

So are you saying that a big name oil let’s say “Castrol Magnatec” as an example (or can you name a similar semi syntheic) will be a better oil in the long term and if so what tests have you done or read about to prove this. I for the life of me cannot find such data, nor do I have the facilities to do such tests or are you like myself and tend to go for a big name because we know no better and may well be paying over the top prices for a similar product. In order to get a warm feeling.

eddie

 

23

 

 

Hi Eddie,

This Carlube oil is semi-synthetic, which actually means very little as the synthetic oil content is not specified, so place very little faith in that part of its specification; a full synthetic will be better, albeit at a cost.

24

 Blimey its all a bit technical .

On a practical level having sold over 8000 cars and serviced quite a few. Older cars were designed for more regular oil changes and most of them are fine with 10w40 semi synthetic changed every 6000 miles or so . They pass more carbon , unburnt fuel , exhaust gasses into the crank case and oil than modern engines so changing the oil for fresh clean stuff can only be a good thing. There build tolerances can be a bit slack so thicker oil helps to fill there imperfections and cushion metal to metal contact . Thin modern oils can let things knock about a bit on an older engine where things are slack ,tired , half worn out and just not built as good as a modern engine.

A modern engine is designed to finer tolerances and for longer services intervals, so modern high spec oils are needed . These oils need to hold there lubricating and cleaning properties for up to 20,000 miles before being changed . Its more critical to get the spec right for these modern engines as per manufacturer recomended data . I’ve had customers thinking they’re saving money putting 10w40 in new fords and they start to run badly and stall purly because the thick oil pumps up the hydraulic tappets and the valves won’t fully close .

In a nutshell in my opinion that’s often wrong {#emotions_dlg.bigsmile}

Older engines get there oil dirtier faster and benifit most from a regular change.

While a modern engine needs the correct spec for its exacting needs.

As for this brand or that brand who really knows {#emotions_dlg.indif}

 

25

Thanks for all the replies, they are all very appreciated.

 

However I am more confused than ever now! But I guess there is no right or wrong answer to my original question so i am going to use it and see how it goes. For £10 a tub if I am not happy I’l just drop it out and replace with another brand. My gut feeling is it’ll be fine though.

 

26

 … also keep an eye out in Asda who often sell Castrol GTX 10/40 Semi-Synthetic for £10 for a 4ltr tub. 

 

27

Asda have Castrol on offer at the moment £12 for 4ltrs.

If I remember it was 5w-30 and 10w-40 

 

Mick

28

It’s a no-brainer - buy two tubs and keep one for the next service.

My local Autoparts sells filters for the Mk1 for £3.40+vat.  Next time I go for one I’ll be buying a spare as well.