10/40 v 20/50

[Johnny M]

Hi there. I have just signed up to the forum but I have to confess I have been a keen viewer over the past 6-8 months. Its a great forum and I have certainly learnt alot!
I got my GS12 in Sept 2005 after 2.5 years with a Blackbird which was faultless. The GS is great and I have no gripes at the moment. I find it a very enjoyable bike to ride long distances and short, agile, well balanced and comfortable.
I have only covered 2200 miles but I have always been a big believer in oil changes and if necessary between services so I changed my oil last weekend. I went over to SPC and they said that BMW now recommended Castrol GP 20/50 instead of the GP 10/40 that the bike came with and was also changed with at the first service. Looking at the chart in the manual it would appear that 20/50 is the 'correct' grade for the climate in this country. However, would a 10/40 be better for start up conditions and provide better protection due to the thinness of its viscosity, enabling it to penerate better and in particular upper cylinder?
I would be very interested to hear of others views.

 

[jeff garnett]

oil

Hi
My bike runs a lot smoother on 20-50
I will be using it again.

 

[Deleted account 211025001]

20/50

Andres

 

[(RIP) Kaister]

Zzzzz

20/50

search

search again

then a bit more.

 

[Iain Hogg]

If it's the same as they 1150, the manual specifies 10W-40 only up to 20C!

I've just been out to get some 15W-40 which takes it up to 30C.

After that it's too hot to ride

Iain

 

[Johnny M]

Thanks guys. Sorry to have woken you up Motomartin. We don't all know the answers especially us newbees. 20/50 it will remain then!

 

[Timolgra]

I went over to SPC and they said that BMW now recommended Castrol GP 20/50 instead of the GP 10/40 that the bike came with and was also changed with at the first service.
I would be very interested to hear of others views.

BMW must be reading this forum for their technical info then

 

[gavin@iow]

Looking at the chart in the manual it would appear that 20/50 is the 'correct' grade for the climate in this country. However, would a 10/40 be better for start up conditions and provide better protection due to the thinness of its viscosity, enabling it to penerate better and in particular upper cylinder?
I would be very interested to hear of others views.

I used Castrol GP 20w50 up to 6000 miles, and now i use Castrol R4 10w50, that covers the UK temp range for all year riding.

 

[IanC]

In my GS, CW told me to use 20w-50 (for 2 years), and now I've changed to a new GSA, Ocean have told me to use 10w-40 (after "checking").

Is that a change, or maybe there are some subtle engine differences (such as closer tolerances)? My new one uses NO oil whatsoever, and seems a lot smoother all round. The old one drank it for perhaps 5000 miles.

 

[Iain Hogg]

In my GS, CW told me to use 20w-50 (for 2 years), and now I've changed to a new GSA, Ocean have told me to use 10w-40 (after "checking").

Is that a change, or maybe there are some subtle engine differences (such as closer tolerances)? My new one uses NO oil whatsoever, and seems a lot smoother all round. The old one drank it for perhaps 5000 miles.

No engine changes, just global warming making the climate down in Plymouth 10 degrees cooler!