Which one of the following oils should I request for an oil change for a petrol 99 GX 24,000 miles please?

These are the choices at National Tyres!






[b]Castrol Magnatec 10W40 Semi Synthetic
£27.00[/b]
or

[b]Castrol Magnatec 5W30 Full Synthetic
£27.00[/b]


Thanks.

SAE 5 - 30 is marked as the preferred oil, but 10/40 is ok as well.
As far as the synthetic bit goes - I'm not an expert by any means - no doubt one of the oily people will give their opinion.

Unless something has changed recently, Magnatec 5/30 is SEMI synthetic.......NOT fully synthetic

Both prices are the same as well, you would expect to pay a premium for FULLY synthetic

Is this a "fitted" price? If not it's jolly expensive :

Personally speaking, I would put 10/40 in a older engine and 5/30 in newer engines. My PERSONAL view is fully synthetic oil is overpriced for the average car, OK if your racing or in harsh conditions, just my personal view (Tin hat at the ready)

Kingo

This includes filter and with discounts I would actually pay less than £20. I think I previously used 10/40 but thought the 5/30 to be a bit of a bargain as it is generally more expensive.

Here is the full list.

[url="http://www.national.co.uk/showoil.asp"]http://www.national.co.uk/showoil.asp[/url]

The Castrol website says Castrol Magnatec 5/30A1 is fully synthetic.....hmmmmm

is there a 5/30 and a 5/30A1 I wonder

Anyway, back on thread, I would personally use 10/40 in an older engine

EDIT

Castrol recommendation

Application Recommendation Capacity (ltr) For RAV 4.1 2.0 Petrol
Engine (Petrol) Castrol's best oil for your vehicle EDGE 0W-30 (h,r) 3.7 ltr
Alternative recommendation MAGNATEC 5W-30 A1


Kingo

I agree with kingo.

Normally I would be drawn to the lower viscosity oil although this flies in the face of tradition - it used to be generally considered that thicker oils gave better protection but it has been proved that lower viscosity oils circulate better especially during the vital cold start up period and resist the build up of sludge and other contaminants (remember the "mayonaise" that used to collect around the filler cap?). A disadvantage of fully synthetic oil with an older engine is that tends to cling more to surfaces which could lead to some consumption problems.

To summarise - in this case I believe the 10W/40 semi-synthetic would be the most sensible choice.

Thanks anchorman and Kingo - I'll take your advice.