What's the lowest that you'll find lava in the nether?

Question

What is the lowest level where lava in the lava oceans will go down to?

Answer 1

I just went to the Nether and did some research with WorldEdit's //count.

Here's how lava is distributed in a 200x200 area:

LB: 0  0  0  0  31 65 30 22 18 19  30  20  20  18  17  18  15  14  9   7   1   168  382  1879  5594  6864  8200  10084  12393  14205  16219  18187  71  38  42  44  55  57  48  85  46  50  52  55  38
%:  0% 0% 0% 0% 0% 0% 0% 0% 0% 0%  0%  0%  0%  0%  0%  0%  0%  0%  0%  0%  0%   0%   1%   5%    14%   17%   20%   25%    31%    36%    41%    45%   0%  0%  0%  0%  0%  0%  0%  0%  0%  0%  0%  0%  0%
Y: 0  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21   22   23    24    25    26    27     28     29     30     31     32  33  34  35  36  37  38  39  40  41  42  43  44  45

(LB - lava blocks in a 200x200 layer at the Y coordinate; % - percentage)

We can see that there's lava starting almost at the very bottom. But big amounts of lava start only from Y: 23, so that may be the answer to your question.