Varying multiple model inputs in MATLAB loop

Hi,

I'm modelling the performance of a car in terms of fuel efficiency using various input parameters (e.g. mass, frontal area etc.) My code loops through time as the car accelerates and reaches a constant velocity. At the moment I have a loop outside of this that varies the model parameters one at a time and I am trying to plot the result of each of these input variations on the one graph but I can't seem to get it to work. The model will plot the last iteration of the loop (I.E Mass, as seen below) but none of the others even though I used hold on. Any help would be greatly appreciated!! Thanks.

for HH = 1:4

for k = 1:40

if (HH==1)

FrontalArea(k)=0.25+0.01*k;

else

FrontalArea(k)=0.4; %0.25-0.4-0.65 m^2

end

if (HH==2)

CoeffRoll(k)=0.001+0.0001*k; %0.001-0.003-0.005

else

CoeffRoll(k)=0.003;

end

if (HH==3)

CoeffDrag(k)=0.15+k*0.0075; %0.15-0.3-0.45

else

CoeffDrag(k)=0.3;

end

if (HH==4)

mass(k)=60+k*2; %60-100-140

else

mass(k)=100; %kg

end

for n=1:5000

%% Here is the loop modelling the car performance over time

end

if (HH==1)

plot(FrontalArea,FuelEff)

xlabel('Normalised Data');

ylabel('Fuel Efficiency (km/kWh)');

title('');

hold on

elseif (HH==2)

plot(CoeffRoll,FuelEff)

xlabel('Normalised Data');

ylabel('Fuel Efficiency (km/kWh)');

title('');

hold on

elseif (HH==3)

plot(CoeffDrag,FuelEff)

xlabel('Normalised Data');

ylabel('Fuel Efficiency (km/kWh)');

title('');

hold on

elseif (HH==4)

plot(mass,FuelEff)

xlabel('Normalised Data');

ylabel('Fuel Efficiency (km/kWh)');

title('');

hold on

end

end