DIY EFIE for less than $5.

[omgwtfbyobbq]

Most cars have a high idle with less load to warm up the engine as quickly and safely as possible in order to minimize wear, on automatics this corresponds to different shift points, since too much load isn't necessarily beneficial for the car when cold. Essentially, everything has to warm up to minimize wear, and the best way to do this is run the engine relatively quickly with little load in order to generate heat. The mixture is also richened to start up the emissions system as quickly as possible.

[MY02WRX]

Ok... Everyone consider this, the more efficient you make your engine, the better mileage your going to get, no if ands or buts. The more useful power your engine makes at its median engine speed the better mileage it will recieive, the smoother your torque curve/a/f curve is the better mileage you will get.

I called my buddy, who has a ba in automotive engineering, told me cold starts are so rich because A. running a lean cold start the fuel is less combustible b. to increase heat in your emissions c. because a lean situation causes combustion chamber heat, but also causes a pollutant called nox, which is worse than unburnt fuel.

He told me if you want to know why running lean is so horrible try finding information on the tests manufacturers did in the 70's when unleaded fuel came out, it created a bunch of stink. Mainly HORRIBLE fuel mileage and horrible emissions.

[skewbe]

Hmm... I know "cold starts" are an issue, where the engine has been sitting overnight and the oil has all run out of the rings and bearings. But cold oil is generally thick oil and possibly a better protector of metal as a result.

Except for real high performance machines with very tight tolerances, is there any evidence that a cold engine is going to wear faster, assuming the oil is flowing? The cold metal will be less likely to gall anyway, no?

[MY02WRX]

yea running a lean cold start is hard on everything, does not idle high enough, and low amounts of cold fuel does not combust as well as a bunch of cold fuel. Also high performance machines use dry sump with perfectly precision oil sprayers/jets. Trust me Honda/nissan/toyota/ect. would not do alot of the things they do if it would harm the engine. They get what they can out of it SAFELY, there are things left untouched that do not pose a threat to longevity, but not single sensors.

[csrmel]

x

[omgwtfbyobbq]

Originally Posted by skewbe

Except for real high performance machines with very tight tolerances, is there any evidence that a cold engine is going to wear faster, assuming the oil is flowing? The cold metal will be less likely to gall anyway, no?

And Bob's yer uncle.

Cold Start" can destroy bearing surfaces and lead to progressive failure. "Cold Start" failure is caused by lack of lubrication and running up to full RMP before the engine is warm.

It is well known in the automotive art that wear in automobile and other vehicle engines of the internal-combustion type is not simply related to the number of miles driven, but depends upon the conditions under which the vehicle is driven. For example, it is recognized that an engine of a vehicle which is utilized for frequent short trips will wear faster (on a per-mile basis) than the engine of a vehicle which is driven less frequently but longer distances. This difference in wear life can be explained, at least in part, by the fact that friction is at its maximum value during the first few minutes after a cold engine is started and that, after the engine has warmed to its normal operating temperature, friction within the engine drops substantially. Some workers in the automotive art have estimated that up to ninety percent (90%) of the total mechanical wear of an engine occurs within a relatively short time after starting the engine cold. In one article on this subject, workers in the art estimated that an automobile engine undergoes the same amount of mechanical wear during the first thirty seconds after it is started cold as the engine would undergo if driven fully warm for five hundred miles. In otherwords, according to this source, the wear during a thirty second cold start of an engine may equal approximately the wear undergone by a fully warm engine over a nine hour period of normal operation. Similarly, The Society of Automotive Engineers has determined that up to eighty percent of the wear on vehicle engines occurs during the first ten seconds of operation. Accordingly, it is clear that critical times for engine wear occur during the period that the engine is being cranked by the starter motor and before the mechanical oil pump of the engine has had sufficient time to fill the oil galleys of the engine with oil at the normal operating pressure.

Etc...

[rh77]

So, let's say it's 20F. I start the car, and immediately place it in "D4". Ker-chunk, and we're off. Letting the vehicle idle along until some signs of warmth has been my style since I started tracking mileage. Cold start idle guzzles the fuel, but is the engine taking a huge hit then?

[theclencher]

best warmup is via gentle use NOT sitting there idling NOT hard use

engines coolant heaters

in fact i'm considering penning a "public service announcement" for the local paper regarding proper use of heaters, proper warmup, and how evil all these dod gamn autostarts are (need to counteract all the stupid shops advertising now to install those stupid things)

[skewbe]

"Accordingly, it is clear that critical times for engine wear occur during the period that the engine is being cranked by the starter motor and before the mechanical oil pump of the engine has had sufficient time to fill the oil galleys of the engine with oil at the normal operating pressure. "

Surely someone has tried an electric oil pump and possibly heater prior to startup then?

[skewbe]

Or an accumulator might be even better

Add a valve to trap some pressure for the next start, maybe wrap it in a blanket?

http://www.moroso.com/articles/artic...&catcode=13600