mwilliams

Can you guys settle an argument for me.

Many people (some on here) and a few mates insist on idling their cars for several minutes when started from stone cold as it's 'kindest to the engine'.

My understanding though is that running the engine when its cold is what is damaging. When you leave it idling it takes forever to warm up, but if you drive pretty much straight away taking it gentle (as in old boy gearchanges well under 3000rpm) then will warm it up a lot faster. Ergo less damaging 'cold run' time, which surely is a good thing.

Thats how i've treated all my cars. This is my first Impreza (indeed my first car with a turbo) But didn't see why the logic should be any different.

Sorry in advance if this SIAL, just wanted to see if i'm doing the right thing!

evander

iTrader: (1)

I tend to go with the let it idle for a minute club, Sure if you drive straight off and keep it under 3000 your going easy on it but your putting more load on the engine than you would be letting it idle. I just let it idle for a minute and then drive but take it easy. Even when the water temp is up I wont cane it, the cooling water may be up to temp but the oil isnt.

TonyBurns

iTrader: (3)

Friction, friction, friction.
You just cant beat physics here, leaving the car to idle causes less friction, but in turn that keeps the oil cold which means it doesnt lubricate as well, getting the heat in there (for which oil is there for and loves ) means that it lubricates quicker (more friction = more heat = hot oil = better lubrication) so leaving the car to idle actually is bad for it when you start up from cold, getting out and warming the engine up is better because the engine/fluids then do their job quicker

Tony

gazza19800sti1

like above oils have operating temps where they work better . i just dont get it on boost and put excessive load on the engine till oil is to optimum lubricating temp. plus next door would go mad and dont think subaru designed engines to have to tick over for two minutes before you set off ... or you could have bought slower car and got there in the same time.

Tidgy

mine gets started, backwards out of the garage, then sat for 30 seconds while i close garage door, then drive off. i keep it under .5 bar and under 3.5k rpm untill oil hits 50 degrees (when it first moves on defi) then under 4k till its up to abot 75-80 then away we go, that takes about 10 mins or so though

gazza19800sti1

tidgy watch mate for twocers . things like this happen to the best of people . i could not leave mine running while i walk off , unless turbo timed .. if that s what you do .. ( just looking out and i am a security freek ) gazza

mwilliams

Cheers

Was fairly sure I had the physics of it right. Good to hear it from the guys that know though.

gazza19800sti1

no problem, just drive steady till oil temp gets up . gazza