Engine Oils

[Rugged Path]

Here in the middle east it gets bloody hot. Yer don't believe me, well i've even fried an egg on my tank.

At present I am using 'Motorex Synt 4T (SAE 10W/60)' but it is imported & expensive. After 30k kms riding, I am planning to change to mineral based Castrol GTX (SAE 20W/50) which is only £4 x 4ltrs. At that price it can be changed more often. I used this oil in the UK for my old boxer with no problems.

But as it gets up to 50 Degrees here, will the oil be able to stand it? Let me know. thanx

 

[BlackBetty]

In the owners manual there is a matrix that shows what oils to use at which mean average temperatures. The 20W50 was for below 16 degree celsius if memory servers me correctly. I am sure some one will probably correct me on this, but you will require a thinner oil at those kind of temperatures with a higher viscosity, 10W60 sounds about right. IMHO

 

[Rugged Path]

Hang on a minute lads. 20W/50 is thicker than a 10W/40. Therefore, the latter is used for cold conditions and the opposite for warmer. If oil is too thick (10W/40) before starting in winter for example, the engine would be more difficult to turn over and slower in lubricating bearings and valves.

What I meant to say is that I believe modern boxers can still run in hot climates on ordinary mineral based oils; aka GTX 20W/50. Which is cheaper for me to buy than the more expensive synthetic oils. It also affords me to change the engine oil more often.

Anybody agree?

 

[wessie]

I don't have the BMW chart at hand. However this site has a table that shows 20W/50 is fine where the ambient temperature does not fall below 0C.

GTX meets the API minimum spec. for my 2000 1150GS. I have been using the 10W/40 "eurolight" version for topping up my UK based bike.

If you believe this site then the 20W/50 will be better for your bike than 10W/60.

The crux of the issue is this: the bigger the difference between the cold oil viscosity and the hot oil viscosity, the more the volume of viscosity modifiers and the less the volume of base stock

As Paragon says, the maximum operating temperature is irrelevant as you'd stop the bike if the temp. guage went too high wouldn't you?

Use the GTX. IMHO it will be fine.