I used aChartEngine and was able to produce a graph with differing axis.
protected void setRenderer(XYMultipleSeriesRenderer renderer, int[] colors, PointStyle[] styles) {
renderer.setAxisTitleTextSize(16);
renderer.setChartTitleTextSize(20);
renderer.setLabelsTextSize(15);
renderer.setLegendTextSize(15);
renderer.setPointSize(5f);
renderer.setYLabels(5);
renderer.setMargins(new int[] { 30, 15, 30, 15 });
int length = colors.length;
for (int i = 0; i < length; i++) {
XYSeriesRenderer r = new XYSeriesRenderer();
r.setColor(colors[i]);
r.setPointStyle(styles[i]);
renderer.addSeriesRenderer(r);
}
renderer.setClickEnabled(true);
renderer.setSelectableBuffer(100);
renderer.setApplyBackgroundColor(true);
renderer.setBackgroundColor(Color.argb(100, 50, 50, 50));
renderer.setAxesColor(Color.LTGRAY);
renderer.setZoomButtonsVisible(true);
renderer.setPointSize(10);
renderer.setChartTitle("Fuel Efficiency and Cost");
//mRenderer.setXTitle("Date");
renderer.setShowGrid(true);
renderer.setXLabelsAlign(Align.RIGHT);
renderer.setYLabelsAlign(Align.LEFT);
renderer.setYTitle(cunits,0);
renderer.setLabelsColor(Color.WHITE);
renderer.setXLabelsColor(Color.GREEN);
renderer.setYLabelsColor(0, colors[0]);
renderer.setYLabelsColor(1, colors[1]);
renderer.setYTitle(dunits, 1);
renderer.setYAxisAlign(Align.RIGHT, 1);
renderer.setYLabelsAlign(Align.RIGHT, 1);
}