PS: Pferdestärke

PS stands for?

Ps = Pferdestärke. Literally "Horse Strength". PS differs from UK
BHP, which differs from US BHP. The reason is that regulations
differ from country to country about the way an engines power output
can be quoted. Most engine builders quote a BHP figure at a
particular revolution rate for the engine, eg 89BHP @ 5500 rpm. BHP
can be directly calculated by taking the torque, multiplying by revs
and dividing by the infamous "fudge factor" - a constant which is
only there to keep the figures manageable.

Now. German regulations are a bit tighter than the UK regulations
when it comes to measuring the power output, hence PS tends to be
lower compared to UK BHP. US BHP is notoriously optimistic, as the
US regs allow for the fitting of special manifolds etc during the
testing. A friend discovered this after putting a Cobra copy with an
American engine on the rolling road, to find that the power was
considerably lower than expected. He did a bit of research and
discovered the US Horses problem.

Steve Dix

Updated 16 Dec 2002