On 23/07/13 11:00 AM, John_H wrote:
> With the appropriate gearing I'd expect the performance to be exactly
> the same, but not for long.
But I'm not talking about changing anything *other* than the engine.
> The reason being that heavy diesels work best from around 80% of their
> maximum power output, and need to be able to maintain that level of
> output continuously whereas most car engines can't. A suitably
> detuned petrol engine with the same power output, as typically used in
> aircraft, would be a vastly better basis for comparison and there'd be
> SFA difference in performance, other than fuel efficiency.
> It's the power to weight improvement associated with forced induction
> that has allowed diesels to compete with petrol engines in cars... not
> the increase in maximum torque which is necessary to attain similar
> power outputs from a similar weight engine, albeit at lower rpm.
You avoided answering the question :)
In this case I'm not concerned about the effects of longevity, or making
changes to suit each particular type. I'm simply asking that if
horsepower remained the same but torque dropped off to one third of what
it was, what would the likely performance differences be?