SOHC or DOHC

**mazingerZ** · November 29th, 2007 04:02 PM

Sirs,

I have this ongoing argument with my friends as to which type of configuration is more fuel efficient, an SOHC or DOHC type engine. I would like to know the pros and the cons of each type. Any inputs would be very highly appreciated.

**4JGtootsie** · November 29th, 2007 06:24 PM

Engines with DOHC heads are more powerful consequently uses more fuel. It usually use more than one exhaust and/or intake valves per cylinder. The openning and closing of valves can be better configured because of the extra set of lobes of an additional cam.

**vito corleone** · November 30th, 2007 12:49 AM

i remember coming across this site before which can answer your question. . .

http://www.samarins.com/glossary/dohc.html

"THOUGH HOME TO US ALL, THE EARTH IS MUTE.
IT DOESN'T GET A VOTE IN ANY CONGRESS OR PARLIAMENT.
IT DOESN'T OWN BLOCKS OF SHARES IN THE MARKET.
IT DOESN'T RISE UP AT A PROTEST RALLY. IT CAN'T EVEN BUY A HYBRID CAR.
THE EARTH HAS NO VOICE--SO WE MUST SPEAK FOR IT."

**speedyfix** · December 3rd, 2007 10:37 AM

fuel consumption is not measured by the number of cams you have, rather by the displacement of the engine and what the intended purpose is.

**niky** · December 3rd, 2007 06:38 PM

fuel consumption really depends, specifically, on the engine.

DOHC heads technically have more moving parts and a heavier valvetrain, which can lead to higher consumption, but that can be designed to be more efficient at a wider range of speeds because of the more flexible breathing allowed by the extra valves.

**washburn** · December 4th, 2007 02:42 AM

funny thing is that my friend's 1.6 4g92 (1st gen) DOHC mivec is more fuel efficient than my 1.6 4g92a SOHC lancer, a 2km/l difference, maybe fuel consumption really depends on what transmission you are using because I got matic and he got manual, hmm