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warming up uses a TON of gas. on cold days its way up at 1800rpm and on top im not moving anywhere (getting 0 mpg) imo i think everyone should be fine even if you did drive it hard right after start up.. i mean just because its "cold" doesnt mean oil isent doing its job.. i was reading a consumer reports article from their used car buying guide and looking at their tips on saving gas, and it said a car should never be idled or "warmed up". They say a car warms up faster by driving it in the first place and would be "warmed up" within a couple of miles of driving with no harm to the car.

 

driving hard on a cold day can bring along with it all sorts of broken suspension issues as stated earlier. There are other parts that need to warm up besides whats under the hood. Cold means the oil is thick and slow to pump and react to changes in demand. besides unless your ian emergency responder, waiting a few minutes isnt going to hurt anything .. unless its somone who just has to cut me off to get that one car length closer to thier destination. They can just go out and drive hard, and i hope thier car breaks :grin:

 

nipper

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I can relate to that emergency responder 'get up and go' stuff, but my old '90 legacy didnt seem to mind too much. The new (to me) 99OBW takes it well too, its just kind of annoying to get to the firehouse at 3:00 in the morning for a false alarm just to turn around and go home again....or worse yet get a first aid call for someone with stomach pain because they didn't eat dinner:banghead:

I do admit though, giving it an extra few minutes in the morning before I begin my commute is worth it, well..heat is nice at least:cool:

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I warm it up regardless outside temperature, probably because I had diesels for quite longtime!?

 

Yeah diesels hate running cold, but they also (at least mine) warm up very slowly when idling. A certain amount of warming up is necessary to get it to actually run, but once the oil pressure is up there for the turbo, it is running smoothly, and the white smoke has ceased, (between 30 seconds in the summer and 4 or 5 minutes in the winter), I either try to start driving it really gently, or I turn all the accessories on to increase load, because otherwise, it can idle for 15 or 20 minutes (when it's 15F outside at least) and still not move the guage off the bottom. I also try to run it nice and hot and floor a few times a day to burn off any carbon buildup during the low temp starts.

 

I've been getting crappy mileage in my truck the last few weeks -- 20-21mpg on the last two tanks instead of 24-25 usually. I think its partly because I'm warming it up longer cause it's been cold, operating at colder engine temps till it warms up which uses more fuel, and probably also because I've been in 4wd going slower too.

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Just my .02 cents, but every single one of my over 20 instructors at school, who all at one point in their lives designed, tested or otherwise worked in some fashion with engines, all said that warming up an engine for 5-10 minutes is bad news, at low rpm, and low temps the oil performs poorly.

 

 

The reccomendation is, let it warm up for 30 seconds to a minute, and then drive away gently until its warmed up. the best thing you can do to an engine is to get it warmed up quickly driving gently and keeping the revs above idle.

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I would agree. Just get the oil circulating and drive within a minute or so. Now on our fleet of busses and our trains it is a bit of a different story. Our trains have two engines, one the size of a bus motor to power the heavy electrics (HEP), and the other the size of a ship engine to power the wheel motors.

The size of the engine and the actual temp outside can have a lot to do with how long a warm up you need to use.

I will defer to our cold weather friends as to what works well on thier cars as the climate is mild here by comparison.

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What's not often mentioned is the fact that engines and some accessories (turbos for example) are designed to be run at particular operating temperatures. I've seen folks from warm climates advocating throwing out the thermostat so that their engine runs 'cool'.

 

Pistons, crankshafts, rods, pumps, and bearings are all designed to clearance properly at operating temperature. Maybe its old fashioned, but I don't put a load on my engines until they are warm.

 

Just an old habit.....

 

Steve

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Here is my rule of thumb for warming up my '05 OBW A.T.---

 

Get in car and don't put on seat belt.

Turn key to ACC and listen for fuel pump to fully charge.

Turn key and start engine.

*First seatbelt warning chimes activates*

-

Wait for *second seatbelt warning chime* to END.

Fasten seatbelt and drive gently.

Don't rev past 3k until temp needle hits first "notch".

Don't rev past 4k until temp needle is showing operating temp.

 

In other words: start it, set heater, seats, mirrors, radio etc and go.

Long idle times simply waste gas and needlessly wear parts ie. belts, hoses, alternators, fans, pumps etc.

 

Juan

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First, I do not know about subaru auto trans, so keep this in mind.

 

I know alot of american made cars and trucks do not circulate the trans fluid in park. For guys who snow plow and haul trailers around they will let the trans sit in neutral to let it cool down.

 

Like I said Subes may be different, but the mechanic wasn't completely wrong in saying that fluid does not circulate in park, some trans don't.

 

 

Beezer

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i disagree. the pump for the transmission is connected to the outside of the torque converter. Whenever the engine is running, the oil in the transmissionis moving. The input shaft of the transmission is connected to the stator, or the guts of the torque converter. This is standard for all automatic transmissions. The oil is not doing any work, but is circulating all the time. This is the same reason you check the tranny fluid level with the car running and not off.. If it wasnt circulating it would be the same as the car is off.

 

nipper

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I agree with Nipper on how I believe they work. The one other thing you might note is that on a worn tranny you often have to select first and reverse and sort of charge them or pump them up with fluid. I have had a couple of cars that would have a slam on engagement when the tranny circulated oil to the clutchs. My Mercedes did this for the last few years before it finally would not shift and required replacement. The clutchs get worn, the pump doesn't quite have all the original pressure, and the seals leak a bit when a tranny is old.

But the oil is circulating through the tranny in neutral and park, just a valve in the vlave body has not opened to route the fluid to a clutch.

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RANT MODE: ON

 

Private franchises, aka: Auto "Dealers" are history (they just don't realize it yet). It's mostly a matter of leaping some legally binding contract issues before they are relegated to corporate-owned, "Distribution / Demo / Service Centers" employing salaried workers.

 

Gone will be the days of haggling for price with monkees that are curiously devoid of information regarding the specs or options on the car you've researched and drooled over for months. Thankfully the price of the car will no longer have to include the commission for useless interference, and gone will be the days of the individual franchise owner deciding how important competence is as a pre-requisite for fixin'-cars.

 

Customers will order their dream car online, selecting the desired color and options from a menu, click "finished" for the price, arrange for insurance and financing on the next page. They will be given a lead-time time for the delivery of their vehicle at the nearest local distributor.

 

The buildings will look the same on the outside, but the buying experience will be streamlined and less painful. The service experience will be more consistant (for better or worse).

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RANT MODE: ON

 

Private franchises, aka: Auto "Dealers" are history (they just don't realize it yet). It's mostly a matter of leaping some legally binding contract issues before they are relegated to corporate-owned, "Distribution / Demo / Service Centers" employing salaried workers.

 

Gone will be the days of haggling for price with monkees that are curiously devoid of information regarding the specs or options on the car you've researched and drooled over for months. Thankfully the price of the car will no longer have to include the commission for useless interference, and gone will be the days of the individual franchise owner deciding how important competence is as a pre-requisite for fixin'-cars.

 

Customers will order their dream car online, selecting the desired color and options from a menu, click "finished" for the price, arrange for insurance and financing on the next page. They will be given a lead-time time for the delivery of their vehicle at the nearest local distributor.

 

The buildings will look the same on the outside, but the buying experience will be streamlined and less painful. The service experience will be more consistant (for better or worse).

 

 

er um, what does this have to do with this thread :banghead:

 

 

nipper

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i disagree. the pump for the transmission is connected to the outside of the torque converter. Whenever the engine is running, the oil in the transmissionis moving. The input shaft of the transmission is connected to the stator, or the guts of the torque converter. This is standard for all automatic transmissions. The oil is not doing any work, but is circulating all the time. This is the same reason you check the tranny fluid level with the car running and not off.. If it wasnt circulating it would be the same as the car is off.

 

nipper

 

I am sure you are right about subaru's, and that is all that matters since this is a subaru forum.

 

Some vehicles you do have to check the trans fluid with the vehicle in neutral. Not all cars are like this, but some are. There are many people who say this, check out forums about rv'ing, plowing etc. I know the older dodges with the cummins are like this.

 

Oh well, if it's not a subaru it's not worth talking about here.

 

 

Beezer

 

 

Have a Merry Christmas everybody!

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