Hitchcocks Forum

Is it ok to top up oil level with another brand ?

I have duckams 20w 50 that was put in about 300 miles ago , i cant seem to find a local store to buy more so was going for castrol . Would it have any disatrous effect by mixing the brands until i vcomplete a full oil and filter change after the summer ?

Reds

It is not the brand but the type of oil that matters, I have not used Duckams 20/50 in many years, I assume it is still a mineral oil so you would need to use mineral oil to top up with

I think Castrol is a multigrade oil not sure what Duckhams is as it was the oil in when I got the bike a few weeks ago anyone know if I could top up with the Castrol if Duckhams is already in there.

Reds

Duckhams 20/50 is multigrade, you could mix Castrol 20/50 if both mineral, but for the small amount in the bike just change it all to a 20/50 oil you can easily get hold of

It will not hurt the engine, use the same viscosity oil if you can, but if out in the sticks with no choice, won`t hurt the engine to use a different viscosity. After all, semi- synthetic oil is a blend of the two. Both are made from the base oil. Don`t worry about it.

Comma Classic 20/50 is good and a reasonable price - you can find it on the interweb (amazon etc.) and post free in some cases.

What model/engine is it? EFI takes 15W-50 semi-synth (such as Castrol Power 1). Not good to mix either viscosity or brand - different additives can counter-act. Since an oil/filter change is a 20 minute job why not just bite the Bullet? (OK, pun intended . . . )

Went and bought some halfords Classic oil 20w 50 in a beautifully old fashioned can.

Great deal 5 litres for 1499

Nigelphoto its a1960 350cc

Reds

You have done the right thing Reds and you can continue using it for future oil & filter chnages.

If the clutch runs in it then you need a JASO API MA1 spec because the clutch plates use a water based cement like an automatic gearbox which dissolve in solvent (normal oil). Modern car engine oils do not meet this spec. Current spec for the EFI which runs everything in the same oil is 15W50 API SL Grade JASO MA semi-synth but full synth e.g. Mobil 1 Race 4T (API JASO MA1) can be substituted. As this is a 1960 350cc (mine pissed hot oil over my boots every time I put it on the centre stand) I assume it has separate fluids for engine, gearbox and primary. Oil goes off, it doesn't last years in an old can, if it smells yuk! it has blown and of no use. Duckhams 20W50 good, mineral oil, think BP owns both Duckhams and Castrol now. Halfords sell a Classic 20W50.