[sawjet]

Can your very ordinary car maintain that top speed at a maximum duty cycle without overheating or causing unnecessary wear to the engine or drivetrain? Have you ever actually used your car at its limits? It's not something that you would want to do for long periods of time. Now imagine your cars limit is 70mph.

[andylynch]

No but this is why you would use a speed limiter rather than changing the engine. This is already done on every HGV in the country and most mopeds.