Clive Arthur wrote:

On 29/08/2019 10:58, Tim+ wrote:
Now I know that in practice it doesn't matter a jot but every time I mix up
some two-stroke fuel I agonise (very slightly) over whether it's one part
oil added to 50 parts petrol or one part oil *in* 50 parts petrol/oil mix
(hence one part oil added to 49 parts of petrol)

So, does a 1:50 mixture equal 2% oil in petrol or 1.96%?

Tim


Well, 1:1 would be equal parts, so 1:50 is 1.96%

Cheers

OTOH, 1 in 2 would be equal parts so one in 50 is 2%. I have seen 2
stroke proportions expressed either way,


--

Roger Hayter