Right engine, wrong mountain

Automotive Industries, Nov, 2003

Regarding your write-up on the new Prius; it is my understanding that an Atkinson engine is one that makes one revolution of the crankshaft for every 4 strokes of the piston. Atkinson took a toggle link press system and changed the press slide into a piston and turned it backwards to have the piston drive the crankshaft. I believe the engine in the Prius is a Miller cycle engine, as first used, in recent times, in the Mazda Milleniia with a supercharger.

Henry Larsen

Via e-mail

According to Toyota, the engine in the Prius is an Atkinson cycle engine. The Atkinson cycle is what's normally referred to as a high-expansion cycle While the original patented Atkinson cycle engine is a very complicated mechanical machine, Toyota achieves its Atkinson cycle through the use of variable-value timing--Ed.

I've enjoyed the magazine for years and like the new look, although I do miss those huge and very informative folding charts from Chilton's days.

In your 'Cars Worth Noting' piece on the Prius you mentioned Mr. Washington observatory. I presume you mean Mr. Wilson! I see mules at that turnoff almost every time I go up there. It appears to be a standard test route.

Stephen Round

Via e-mail