boombang wrote:At idle your engine isn't efficient, you're won't necessarily getting a clean burn and possible causing/increasing carbon build up and valve seat burn.
If starting up from cold and leaving idleling, the engine will warm up slowly. Extra fuel on cold start maps can cause bore wash, and of course oil won't be moving round the engine as freely or providing it's best lubricating properties as cold.
Load on various engine components is actual higher at idle than higher RPMs at small throttle openings, this again can contribute to engine wear.
Also oil pressure is lower at idle than higher RPM, this again won't help oil circulation, lubrication and the oil to get to an efficient operating temp.
I never let a cold engine sit at idle to warm up in the UK climate - if perhaps we got down to serious extremes I would at least let the engine get some heat before risking any revs, however we don't.
Gentle driving, holding up to say 2.5k revs on light throttle openings is a far kinder way to drive a cold engine.
Oh dear! Ive always it as better for the engine if i let it warm up a bit before i drive it! i let it idle for about 5-10 mins..
