Engine Oil

[gt_james]

Hi Guys,

I am looking for engine oil for my NA 13B. I am not using omp and am premixing. After a bit of research it seemed a lot of people recommend using Castrol GTX 20w50. Does anyone know where to get hold of it in the UK? Or what other options are there here? I have previously used halfraud's own 20w50 mineral oil and also Kroon 20w50 mineral oil, but I would prefer to use a more well known brand with my new engine, something tried and tested for rotaries.

I am not opposed to using synthetic, but I would go for a good mineral if it's cheaper

[A7RXY]

James I'm not sure it's called GTX nowadays as the 20W 50 is called Castrol XL. I use Castrol Magnatec 10W 40 but its part synthetic and have done so for the last 10 years, but mine is a 12A.

Dibs

[gt_james]

I have read that part synthetics leave a lot of ash residue. May not be an issue as I will be premixing, but seems like mineral or full synthetic is better than semi.

[A7RXY]

James I've just edited my post, Castrol do a 20W 50 but it's called XL.
You can buy it online through Rimmer Bros.
Dibs

[DKWW2000]

You are probably aware of sudden changes with oil types in rotaries is not a good idea if you have been running the engine on Mineral not to suddenly change to synthetic as it can damage the oil seals causing them to swell and get misshapen, that being said GTX is semi/part so they have already been introduced to it.
The other important consideration is the viscosity as I do not know if fully synth is available in that grade. I have always used mineral with synth pre-mix in the fuel @ 300 -1 (Stihl 4 mix).
There are pages & pages of advice on all of the sites for all makes of rotary but no difinitive answer.
The damage caused by sudden change does make sense to me.

[MelloYello]

CASTROL GTX is a semi synthetic.

I do not think they do 20/50 any more, but there is 10/40 and 15/40.

try ebay or eurocarparts

[Hobbawobba]

^ Eurocarparts always works out fairly cheap. Find a code and you're sorted. Or jump in on their "up to 60% off this weekend only!!!!" Deals.. Every week

[gt_james]

I have read that sometimes using synthetics cause seals to swell in high mileage engines used to mineral, but I have a low mileage engine and I would not be opposed to running synthetic in it.

I know there is now a semi synthetic GTX. It always used to be a mineral oil, but in America it seems 20w50 GTX mineral oil is still available and is what most people recommend on forums.

Is the Castrol XL classic stuff in a tin the best option in the UK then?

Do other people in the UK use 15W40 and 10w40 then? I've always used 20W50

[Hobbawobba]

That Mobil Super 1000 I use is a mineral 15w40 aye bro! I was gonna go with GTX but I wanted it on the day (from halfords) haha

[MelloYello]

it is oil - just chuck it in