RE: Engine design question

[glen <gpowell@acacianet.com>]

I think this was discussed a few months back, so you might want to check the
archives.  Audi decided on a 2 valve engine (after manufacturing DOHC 4
valve I5s for quite some time) for a little known, but very good reason: 2
valve engines produce better torque in the low to mid rpm range where a
driver spends over 90% (with the exception of several q listers) of his
time.  A flat torque curve is far more important for everyday driving than
top-end power.  A 4 valve engine breathes better at higher rpms and can thus
generate more power, but at the expense of decreased low-end torque (ever
driven an Acura? you'll know what I mean).  
<snip>

Andrew Speer.

Yep, exactly. Engineering for real over-the-road performance and not high-quoted-HP engineering-for-specmanship. Same as spacing the gear ratios for the best over-the-road performance and not for eliminating a shift to get a lower 0-60 specification at the expense of overall performance, flexibility and economy.

-glen