T1000

Hi,

As I work approx 11 miles away from my home so I do around 22 miles a day, I tend to not go on much longer journeys.

I know it's not good to do lots of short journeys as the car doesn't have time to warm up as much as it needs to protect the engine. I also know that every car (Imprezas in particular) need warming up and cooling down properly so that the oil is the right temperature.

The problem is that as I only ever do 11 miles do I need to do anything differently with my driving style?

It's annoying as I don't really put my foot down at all on the commute as by the time it's warmed up I'm at the end of my journey.

Any ideas?

Thanks

GlesgaKiss

Hi, I would'nt worry too much about the cooling down thing. Owners do that to let the turbo cool down after a thrashing: not actually anything to do with the engine. In your case you sound as if you stay off boost until oil is up to temp(which is the right thing to do), so you don't need to let the engine idle when you stop anyway.

Some people go a bit crazy with turbo timers etc, but it is a complete waste of time. Cruising at say 50 using no boost at all is the same for the turbo as sitting on your drive idleing, so you can just pull up and switch the engine off straight away.

If you've driven the car hard, give it a minute or so to idle before switching it off. Although as you say, you won't have much chance to do that in 11 miles(I usually give it about 6 or so before using alot of boost).

dunx

iTrader: (3)

My oil is at a normal temperature within three miles of home (85 degrees)
So most of your journey is fine IMHO.

HTH

DunxC

T1000

Thanks for your replys. I was thinking, also another thing is that I'm using 5w/40 oil which should help with my short journeys.

That's useful info about switching off, thanks Alan. So far I've always let it idle for about 1 minute after every journey but if I don't drive it hard it'll be good to switch if off straight away.

I guess the only way round my constant short journeys is to treat the car (and myself) to a longer journey once a week to blow the cobwebs away :-)

dunx

iTrader: (3)

The idling thing is about super-heated turbo's frying their oil onto the shaft if stopped abruptly. There is little need for a "cooling down" procedure if you are just commuting, being stood still with no air-flow is probably only heating things up more in my humble opinion....

DunxC

Barnsleywrx

hi just a quick question on this, my commute to work is only 4.5 miles do you think this will be ok for the engine? warming oil etc? thanx in advance.

jonny_693

iTrader: (5)

Its been said many times before that 5w/40 is too thin for scoobys, you should be using 10w40, 50 or 60

s70rjw

iTrader: (2)

If you are doing lots of short journeys, you may want to change your oil more frequently as condensation builds at the top of the crankcase. The short journeys means this does not have opportunity to evaporate. I change my Blobs oil every 6 months as I do a similar journey as you regularly

ALi-B

iTrader: (1)

The biggest problem with short journeys is moisture and excess fuel in the engine doesn't get boiled off.

The end result is sludge and cream - remove the oil filler cap and there it is! (making people think the head gasket is gone; it hasn't, just moisture and damp ).

Two ways round this; Change the oil more frequently or use a better detergent oil. You don't say what year car it is; if its a classic then using a 5w40 is a good idea, its not too thin, its the same hot thickness as 10w40 but with better cold properties.. If its a newage car, you can even swap to a 5w30 (not STi).

As for change intervals, a 6 month interval is what I'd advise as a maximum. Alternatively, use a cheaper semi-synthetic oil and change it every 3 months.

A run every week will help clear it. Not only boil off the moisture in the crankcase, but also help clear out the combustion chambers, as they will get fouled from running rich (during warm-up ), causing misfires and spark plug fouling.

The warm-up/warm-down thing is over subscribed. Letting the engine idle or pootling along at sub 2000rpm only prolongs warm up times. Maybe if you use a super thick oil like 15w-50 during winter it probably helps against oil pump cavitation when the oil is still cold, but otherwise its no big issue. Just obviously its not clever to bounce it off the rev limiter either . Same with warming down; there is no need unless the car has just had a hard blast or literally just come off a high speed motorway run (i.e motorway services).

Barnsleywrx

thank you for the info. its put my mind at rest. i am changing the oil every 3k.and i'll take it for a good blast sunday morning. cheers

the bear1986

iTrader: (8)

this is a really usefull thread thanks. when you say you change your oil every 3k do you do it yourself?

ShaggyDooWRX

iTrader: (3)

The subaru manual actually specifies 5W30 and I use 5W40 Silkolene Pro S as advised by Opie Oils