Convert 32:1 to 40:1 (2 stroke)

[Ed talk]

I have a bottle of Honda Pro 2 stroke oil 32:1 and would like to convert to 40:1. Should I add 0.8 oz and make it 4oz for a gallon? Just don’t want to leave it on the shelf for nothing……. Yes I’m struggling Thanks!

 

[ripcord]

3 ounces of oil per gallon is 42.6:1

 

[bunnspecial]

Not sure I'm following your question. If it's 4 oz. of oil, adding it to a gallon would give 32:1. If you desire 40:1, you can either measure 3.2 oz. out of the bottle, or if you add 4 oz. to 1.25 gallons of gas you will end up at 40:1.

What are you intending to run this in? What does that equipment call for? There's usually nothing "special" about a given oil that it has to be used at a certain ratio. The little pre-measured bottles are a convenience tool to allow you to mix at certain ratios, but relatively speaking you often pay a premium for this. I often buy in quart bottles and measure per tank...

 

[MRC01]

Several ways to solve this. One is to convert everything to percentages.
32:1 = 1/33 = 3.03% oil
40:1 = 1/41 = 2.44% oil
The difference is 0.59% of pure oil.
When converting ratios to percentages, remember to add +1 for the total. For example 2:1 is 2 parts to 1 part, which is 1/3, not 1/2.

A gallon is 128 oz, and 0.59% of 128 is 0.757 oz. If that's where your 0.8 Oz came from, it is close enough.

However, the problem is that 32:1 already has more oil than 40:1, so you can't convert 32:1 to 40:1 by adding oil. Adding 0.8 oz. of pure oil to 1 gallon of mixture that is already is 40:1, converts it to 32:1. To convert a 32:1 mixture to 40:1, you would add pure gasoline.

 

[Cujet]

32 to 1 is really close to the ideal mixture for a great many two strokes.

 

[Nessism1]

128 oz/gallon
40:1 = 128/40 = 3.2oz
32:1 = 128/32 = 4.0oz
A .8oz difference

 

[MRC01]

128 oz/gallon
40:1 = 128/40 = 3.2oz
32:1 = 128/32 = 4.0oz
A .8oz difference

That's close, but as mentioned above, you forgot to add the +1.
40:1 has 41 total parts, which is 128/41 = 3.12 oz per gallon.
32:1 has 33 total parts, which is 128/33 = 3.88 oz per gallon.

.. To convert a 32:1 mixture to 40:1, you would add pure gasoline.

How much gasoline to add? A gallon of 32:1 contains 3.88 oz oil and 124.12 oz of gas.
How much gasoline would you need for that 3.88 oz to be 40:1? 3.88/(1/41) = 159 oz
The 1 gallon 32:1 mixture you already have has 124.12 oz of gas, so you need 159-124.12 = +34.88 oz more
So if you have a gallon of mixture at 32:1, adding 34.88 oz of pure gasoline makes it 40:1.

 

[FowVay]

I have a bottle of Honda Pro 2 stroke oil 32:1 and would like to convert to 40:1. Should I add 0.8 oz and make it 4oz for a gallon? Just don’t want to leave it on the shelf for nothing……. Yes I’m struggling Thanks!

A 40:1 mixture ratio is LESS oil in the mix than is a 32:1 mixture ratio.

The Honda HP2 oil is 32:1 so you'd mix 1 ounce of oil per quart of gasoline OR 4 ounces of oil per gallon of gasoline.
If you wish to mix the HP2 at 40:1 then you'd use less oil and mix 0.8 ounces of oil per quart of gasoline OR 3.2 ounces of oil per gallon.

 

[Ed talk]

Not sure I'm following your question. If it's 4 oz. of oil, adding it to a gallon would give 32:1. If you desire 40:1, you can either measure 3.2 oz. out of the bottle, or if you add 4 oz. to 1.25 gallons of gas you will end up at 40:1.

What are you intending to run this in? What does that equipment call for? There's usually nothing "special" about a given oil that it has to be used at a certain ratio. The little pre-measured bottles are a convenience tool to allow you to mix at certain ratios, but relatively speaking you often pay a premium for this. I often buy in quart bottles and measure per tank...

Thanks! I have a 2 stroke 1978 Honda Hobbit/PA50. Just got the new cylinder and want to see if this brand Honda Pro will treat it better.

 

[Ed talk]

Several ways to solve this. One is to convert everything to percentages.
32:1 = 1/33 = 3.03% oil
40:1 = 1/41 = 2.44% oil
The difference is 0.59% of pure oil.
When converting ratios to percentages, remember to add +1 for the total. For example 2:1 is 2 parts to 1 part, which is 1/3, not 1/2.

A gallon is 128 oz, and 0.59% of 128 is 0.757 oz. If that's where your 0.8 Oz came from, it is close enough.

However, the problem is that 32:1 already has more oil than 40:1, so you can't convert 32:1 to 40:1 by adding oil. Adding 0.8 oz. of pure oil to 1 gallon of mixture that is already is 40:1, converts it to 32:1. To convert a 32:1 mixture to 40:1, you would add pure gasoline.

Thanks!

 

[Ed talk]

32 to 1 is really close to the ideal mixture for a great many two strokes.

Thanks

 

[Ed talk]

Thanks

128 oz/gallon
40:1 = 128/40 = 3.2oz
32:1 = 128/32 = 4.0oz
A .8oz difference

 

[gman2304]

I’ve used Echo Powerblend Gold for years, 2.6 oz to a gallon of 89 octane for a 50:1 ratio. Never a problem.

 

[Ed talk]

That's close, but as mentioned above, you forgot to add the +1.
40:1 has 41 total parts, which is 128/41 = 3.12 oz per gallon.
32:1 has 33 total parts, which is 128/33 = 3.88 oz per gallon.


How much gasoline to add? A gallon of 32:1 contains 3.88 oz oil and 124.12 oz of gas.
How much gasoline would you need for that 3.88 oz to be 40:1? 3.88/(1/41) = 159 oz
The 1 gallon 32:1 mixture you already have has 124.12 oz of gas, so you need 159-124.12 = +34.88 oz more
So if you have a gallon of mixture at 32:1, adding 34.88 oz of pure gasoline makes it 40:1.

Thanks

 

[ripcord]

That's close, but as mentioned above, you forgot to add the +1.
40:1 has 41 total parts, which is 128/41 = 3.12 oz per gallon.
32:1 has 33 total parts, which is 128/33 = 3.88 oz per gallon.


How much gasoline to add? A gallon of 32:1 contains 3.88 oz oil and 124.12 oz of gas.
How much gasoline would you need for that 3.88 oz to be 40:1? 3.88/(1/41) = 159 oz
The 1 gallon 32:1 mixture you already have has 124.12 oz of gas, so you need 159-124.12 = +34.88 oz more
So if you have a gallon of mixture at 32:1, adding 34.88 oz of pure gasoline makes it 40:1.

This is not how the industry calculates it. If you buy a bottle of oil to make 1 gallon of 50:1, it's 2.6 ounces. One to make 40:1 is 3.2.

 

[MRC01]

This is not how the industry calculates it. If you buy a bottle of oil too make 1 gallon of 50:1, it's 2.6 ounces. One to make 40:1 is 3.2.

So if it said 2:1, you would take 128/2 and do 64 ounces per gallon? That would be half, not 1/3 which is what 2:1 means.

 

[ripcord]

So if it said 2:1, you would take 128/2 and do 64 ounces per gallon? That would be half, not 1/3 which is what 2:1 means.

Sorry, I should have been clearer. In your example, you would add 64 ounces of oil to a full gallon of gas to make 2:1 and end up with 1.5 gallons of mixed fuel.

So a premeasured bottle for one gallon of 50:1 would yield 2.6 + 128 = 130.6 ounces.

 

[ripcord]

Edit: Double post

 

[FowVay]

Guys, come on. It's a ratio. Two black marbles to one white marble gives you a 2:1 ratio. Naturally you'll have 3 marbles when you're finished but that's not what dictates the ratio.

Two ounces of gasoline to 1 ounce of oil is a 2:1 ratio.
128 ounces of gasoline (2 sets of 64) to 64 ounces of oil is a 2:1 ratio

I wonder if the Professor on Gilligan's Island had this discussion with Gilligan while he was making his radio batteries out of coconut milk and salt water?

 

[MRC01]

Sorry, I should have been clearer. In your example, you would add 64 ounces of oil to a full gallon of gas to make 2:1 and end up with 1.5 gallons of mixed fuel.
So a premeasured bottle for one gallon of 50:1 would yield 2.6 + 128 = 130.6 ounces.

Yep, exactly. The +1 is needed only if you want the total mixture of both together to be 1 gallon. If you've already got 1 gallon of pure gas and are calculating how much oil to add to it, don't use the +1.