Page 1 of 1
How much oil
Posted: Fri Sep 10, 2010 10:41 am
by simonseagull
Hi guys I need to mix 3litres of petrol 10:1 I need to know how much oil in ml please and I'd like to thank the guys in Maine for there help lately. I have stripped carb checked points with help of father in law old salty dog Colin
Re: How much oil
Posted: Fri Sep 10, 2010 11:16 am
by Charles uk
3 litres = 3000 ml
3000 ml divided by 10 = 300 ml.
Re: How much oil
Posted: Fri Sep 10, 2010 1:07 pm
by Keith.P
10:1 or 1 gal fuel to 12.8 oz oil.
Re: How much oil
Posted: Fri Sep 10, 2010 8:49 pm
by Vic
pizey wrote:10:1 or 1 gal fuel to 12.8 oz oil.
Thats fluid ounces in a
US gallon.
A UK, or Imperial, gallon is bigger
Its 16 fluid ounces in a UK gallon
Re: How much oil
Posted: Fri Sep 10, 2010 10:45 pm
by Keith.P
Someone better tell John his site information is wrong then.
As I use TCW3
Re: How much oil
Posted: Fri Sep 10, 2010 11:16 pm
by Charles uk
As the specific gravity of TCW3 is 0.8
& a UK gallon of water with an SG of 1.0 weighs 160 ounces, a 10 : 1 mix requires the same volume of oil as 16 ounces of water, which of TCW3 will weigh 12.8 ounces or 16 fluid ounces.
Too bloody confusing, use metric!
Ps the US gallon (128 ounces) at 10 : 1 requires 10.24 ounces of TCW3 by weight or 12.8 fluid ounces.
Re: How much oil
Posted: Sat Sep 11, 2010 2:51 am
by atoyot
Charles uk wrote:...a UK gallon of water with an SG of 1.0 weighs 160 ounces, a 10 : 1 mix requires the same volume of oil as 16 ounces of water, which of TCW3 will weigh 12.8 ounces or 16 fluid ounces.
This is the first time I've seen anyone refer to oil/fuel ratios using weight rather than volume. It seems a bit out of place, whereas "one part in ten" refers to a "part" of the same type measurement which, in this case, is in volume. That the term "ounce" in the antiquated system of measurement (still used in the U.S.) can mean volume
or weight seems superfluous to the discussion unless I'm being unnecessarily thick just now.
In other words, it would seem equally odd to measure litres of petrol against grams of oil.
It's getting late, time for another cold one. Perhaps that'll clear it up.
Re: How much oil
Posted: Sat Sep 11, 2010 9:29 pm
by Vic
This is the first time I've seen anyone refer to oil/fuel ratios using weight rather than volume.
The references should be to
fluid ounces which are units of volume. It is common practice in the US however to simply refer to them as ounces.
A US gallon is 128 fluid ounces
An Imperial (UK) gallon is 160 fluid ounces.
However there is even a small difference between US and Imperial fluid ounces: 1 Imp. fl oz ≈ 0.96 US fl oz
So if you are in the USA you measure your "gas" in US gallons and your oil in US (fluid) ounces
Anywhere else in the world you use litres and millilitres

Re: How much oil
Posted: Sat Sep 11, 2010 10:29 pm
by billyboy
does nobody on this forum understand the difference between mixing something 1 part IN 10 (10 parts in total) and 10 TO 1(11 parts in total)?if you add 100 ml of oil to a litre of petrol then it is mixed 1 part IN 11 which of couse is 10 TO 1.......NOT 1 IN 10!!
Re: How much oil
Posted: Sat Sep 11, 2010 10:58 pm
by Vic
billyboy wrote:does nobody on this forum understand the difference between mixing something 1 part IN 10 (10 parts in total) and 10 TO 1(11 parts in total)?if you add 100 ml of oil to a litre of petrol then it is mixed 1 part IN 11 which of couse is 10 TO 1.......NOT 1 IN 10!!
If you mix 1 part of oil in 10 parts of petrol that makes 11 parts total
If you mix 1 part of oil to 10 parts of petrol that also makes 11 parts total and it is what it says in the Owners Handbook
If you mix 1 part of oil with 10 parts of petrol that makes 11parts total as well
Are you suggesting we should use 1 part oil + 9 parts petrol
I mix my Seagull fuel 1:25 or 40 mls oil with 1 litre of petrol

Re: How much oil
Posted: Sat Sep 11, 2010 11:54 pm
by billyboy
Are you suggesting we should use 1 part oil + 9 parts petrol
no...... merely suggesting that that is what 1 IN 10 means to me! if you had 1 chance in 10 to win a bet say... then there would be nine chances against you and the odds would therefore be 9 TO 1! not the same thing i hear you say?....think about it
Re: How much oil
Posted: Sun Sep 12, 2010 2:49 am
by atoyot
Vic wrote:
The references should be to fluid ounces which are units of volume. It is common practice in the US however to simply refer to them as ounces.
That was my point - the gentleman to whose post I was replying was matching apples with oranges by comparing the volumetric 'ounce' with the gravitational one.
Vic wrote:Anywhere else in the world you use litres and millilitres

Be that as it may, it doesn't change the need to stick with like kinds of measurement either way. The Seagulls' tanks hold what they hold in either system and I doubt the engines care how we arrive at the proper oil ratio as long as we arrive at it.... give or take a part :-p And I'm with Vic on how that works out though, where the interpretation that's used colloquially in the marine world is the interpretation that's correct. 10 shot glasses of Petrol (or 25 if you like), and one shot glass of oil.
I work in a research environment and prefer the metric system over this slop we use for measuring consumer commodities & distance.
EDIT: An interesting note on the use of the term "gas" to describe petrol in the United States - I was researching "Coleman Camp Fuel" and ran up on the history of early motor fuels. That information suggests that natural gas condensate derived from well heads or pipelines was used as a motor fuel for a time. One can see how the use of the term "gas" might carry over from the non-liquid form from which that liquid came. Here's the source info -
http://en.wikipedia.org/wiki/Drip_gas
Re: How much oil
Posted: Sun Sep 12, 2010 3:05 am
by chris
OH MY GOD I AM SO CONFUSED
does that mean the way I have been measuring out the oil fuel mix as 10/1 for the past 35 years is wrong, I never thought that this could be so complicated, but it is interesting.
Re: How much oil
Posted: Sun Sep 12, 2010 3:21 am
by atoyot
chris wrote:OH MY GOD I AM SO CONFUSED
does that mean the way I have been measuring out the oil fuel mix as 10/1 for the past 35 years is wrong, I never thought that this could be so complicated, but it is interesting.
It's interesting on a philosophical level except that one first has to ignore the historical interpretation of oil mixology. Compare to betting? OK. If I loose a 10-to-1 bet, I'm going to be 'asked' to forfeit ten times my wager, not nine, and the difference between saying "10 'in' 1" versus saying "10 'to' 1" holds up mathematically on the chalk board but not on the warf where people ready their boats for sea. That is to say that the difference is a semantic one that is far overshadowed by the way people do this in the real world.
You've been doing it just fine for 35 years.