Manipulate[
 ContourPlot[r*(y/x), {x, 20, 42}, {y, 20, 42}, 
 ContourStyle -> 
 Directive[RGBColor[1., 0.77, 0.], Opacity[1.], 
 AbsoluteThickness[1.999], Dashed], ContourLabels -> False, 
 Contours -> {27, 28, 28.5, 29.5, 47, 49, 50, 52, 94, 96, 97, 99}, 
 ContourShading -> {Red, Orange, Red, Orange, LightGray, Orange, Red,
 Orange, LightGray, Orange, Red, Orange, Red}, 
 
 PlotLabel -> 
 Row[{"Was I Speedy? if your speedometer reads ", 
 NumberForm[r, {4, 0}], " mph, you're actually traveling to: ", 
 NumberForm[r*y/x, {4, 0}], mph}], 

Axes -> True, Ticks -> True, 
 ImageSize -> 674, AxesOrigin -> {20, 20}, AspectRatio -> 0.65, 
 Epilog -> {{Dashed, Line[{{x, 42}, {x, y}}], 
 Line[{{20, y}, {x, y}}]}, {AbsolutePointSize[32], 
 Inset[car, {x, y}]}}], {{x, 30, "old tire diameter inches"}, 20, 
 42, 0.1, Appearance -> "Labeled"}, {{y, 30, 
 "new tire diameter inches"}, 20, 42, 0.1, 
 Appearance -> "Labeled"}, {{r, 45, "Speedometer reading in mph"}, 
 30, 80, 1, Appearance -> "Labeled"}]

![Speedometer][1]

I think the title of my project is displaying very small and I would like be with a larger font. I have tried different strategies but with no success.
If someone can help me I would appreciate it. Thanks


 [1]: https://i.sstatic.net/oGZkG.jpg