It would help to have the data.
That aside, the plot would go something like this (I got tired of all that typing, so there are just three levels) —
x = linspace(0, 6E+3, 250).';
eff86 = [2E+3*cos(2*pi*x/max(x))+3E+3 1E+2*sin(2*pi*x/max(x))+1E+2];
eff90 = [1.750E+3*cos(2*pi*x/max(x))+3E+3 0.75E+2*sin(2*pi*x/max(x))+1E+2];
eff94 = [1.50E+3*cos(2*pi*x/max(x))+3E+3 0.5E+2*sin(2*pi*x/max(x))+1E+2];
% eff95 = 1.75E+3*[cos(2*pi*x/max(x)) sin(2*pi*x/max(x))];
% eff96 = 1.50E+3*[cos(2*pi*x/max(x)) sin(2*pi*x/max(x))];
figure
plot(eff86(:,1), eff86(:,2))
hold on
plot(eff90(:,1), eff90(:,2))
plot(eff94(:,1), eff94(:,2))
% plot(eff95(:,1), eff86(:,2))
% plot(eff96(:,1), eff86(:,2))
hold off
grid
xlabel('Motor Speed (rpm]')
ylabel('Torque [Nm]')
figure
surf([eff86(:,1) eff90(:,1) eff94(:,1)], [eff86(:,2) eff90(:,2) eff94(:,2)], (ones(numel(x),3).*[86 90 94]))
xlabel('Motor Speed (rpm]')
ylabel('Torque [Nm]')
zlabel('Efficiency [%]')
colormap(summer(2))
colorbar
Make appropriate changes to get the result you want.
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