[JRHAWK9]

Well driving does warm the car faster than idling. That means less time you're running a rich fuel mixture. Though unless your commute is only 5 miles, I find this dramatic a difference surprising. After all, the difference in warm up time would be 2-3 minutes at most.

yep. Before I would start it before I brushed my teeth, put my shoes on and ran up stairs to say bye to the other half. It'd would running for around 5-8 minutes before I got in it.

My commute is about 15 minutes.

 

[MA Subie]

yep. Before I would start it before I brushed my teeth, put my shoes on and ran up stairs to say bye to the other half. It'd would running for around 5-8 minutes before I got in it.

My commute is about 15 minutes.

Oh, OK that explains it.

 

[kr_xv]

Well driving does warm the car faster than idling. That means less time you're running a rich fuel mixture. Though unless your commute is only 5 miles, I find this dramatic a difference surprising. After all, the difference in warm up time would be 2-3 minutes at most.

The Subaru engine really run rich during cold so a lot of short tripping and idle with blue light consumes a lot of petrol

 

[kr_xv]

To make a long story short, I always wait for the blue light to turn off in the morning or if it is winter and the car was sitting in a parking lot for a few hours. In my opinion, if you want your powertrain to last, you have to wait for the revs to drop to idle levels.

Here is the long story:
My CrossTrek is now 6 years old and has 179K. No engine or transmission problems whatsoever and I believe that this has a lot to do with waiting for the blue light to turn off (kind of). If the car has been sitting for a long time during the winter, I always wait for the blue light to go off. Keep in mind that warming up the engine also warms up the transmission fluid and that helps a lot with the transmission life. It bothers me too that running the engine on 2K revs to warm it up is just burning gas without producing any valuable work but I use my CrossTrek as a work tool and burning a bit extra gas to keep it running for years to come saves me a lot more money than having to repair a transmission or replace the car early.
Having said that, I believe that the blue light does a bit more than checking the engine temperature. Sometimes, the car is warmed up and ran for a few miles. Then I shut it off for 10-15 minutes and when I start it back up the revs go to 2K again like it needs to warm up. My theory is that it is checking the catalytic converter or manifold temperature and it revs up to bring it to operating temperature. In any case, when this happens, I know that the car engine and transmission are warm enough so I just put it in gear and go.

the blue light is checking coolant temperature, it will goes off once the coolant reach around 60-70 degree Celcius

 

[JRHAWK9]

The last couple times starting it cold I was able to get the idle to come down after about 30+ seconds or so of it being started. When you start it cold, you'll notice that after about ~30 seconds of the engine running, the car changes idle a bit...kinda goes down and then back up. After this happens I then put it in neutral. Once it's in neutral, the idle drops to a normal idle speed after a few seconds. Then one can put it in gear without being on high idle. It also seems to take care of the car wanting to run at such high RPM's when the blue light is on. This has been my experience the past couple of times.

 

[JRHAWK9]

Just got back from taking it lunch.

Started the car to leave and it did what I described above and it worked great. Car was sitting for ~5 hours. Drove the car 1/4 mile and turned it off, the blue light never went off. Got my sub in about 10 minutes and tried it to head back to the office and it never fluctuated the idle speed after ~30sec of being started. It also didn't drop the idle when I put it in neutral. So it appears this will only work when the car is cold and has sat for awhile.

 

[whs06c]

If I start the car and if the blue light is on, I'll notice some 'surges' from the engine speed. I don't experience any issues after the light is gone though.

 

[E92FF]

I voted C but I’m not sure exactly what you meant by letting the car settle in. If you mean waiting for it to come off high idle then I don’t do that. If it’s cold I’ll give it 10-15 seconds before putting it into gear. Just enough to get oil circulating. Then I drive it easy for the first 5-10 minutes regardless of when the blue light goes off.
One of the things I don’t like about this car is the lack of a real temperature gauge. I like to know what’s going on with the car. My truck has a digital monitor that can display something like 70 PID’s. When I’m towing I’ll keep an eye on around 8 different things. It’s alerted me to a couple issues I was able to address before they disabled the truck and left us stranded on a long trip!

 

[WoodyVT]

Bravo for me. 6 speed doesn't appreciate being thrown into gear when it's cold either so I have to take it easy or the trans makes me XD

 

[Closed Case]

Here's a pic of an instrument cluster from a 1968 Chrysler, courtesy of eBay. Pretty classy!

 

[Closed Case]

Some of us remember cars that had a manual choke. It would do the same without all the computers fuel injectors.

Opel Sport-Wagon 1974 - I had that colour and make. Upgraded to a dual-barrel from single off a Miata or maybe a 2 barrel to a 4?

Lada Nivia 1994, came new pre-rusted, and the only vehicle that could start at -30°C in Россия.

То были времена. .

Da!

 

[Closed Case]

Well driving does warm the car faster than idling. That means less time you're running a rich fuel mixture. Though unless your commute is only 5 miles, I find this dramatic difference surprising. After all, the difference in warm up time would be 2-3 minutes at most.

What MA Subie said. Wheel bearings grease, transmission oils, differential oils, brake hydraulics, and those systems, as well as power steering fluids [non-electric aid], and the pure resistance forces warm up faster. Just keep the RPM as all have said, low..

 

[Resqu2]

I just got a new Crosstrek Sport and saw that light this morning and had no idea what it even was till just now. Glad I saw this post.

 

[MA Subie]

What MA Subie said. Wheel bearings grease, transmission oils, differential oils, brake hydraulics, and those systems, as well as power steering fluids [non-electric aid], and the pure resistance forces warm up faster. Just keep the RPM as all have said, low..

More like keep a light foot on the accelerator pedal regardless of RPM. For us MT folks, lugging the engine is at least as detrimental as revving at high RPMs.

 

[MA Subie]

I just got a new Crosstrek Sport and saw that light this morning and had no idea what it even was till just now. Glad I saw this post.

If you look closely, it's in the shape of a thermometer if that's a clue.

 

[wriggly]

The last couple times starting it cold I was able to get the idle to come down after about 30+ seconds or so of it being started. When you start it cold, you'll notice that after about ~30 seconds of the engine running, the car changes idle a bit...kinda goes down and then back up. After this happens I then put it in neutral. Once it's in neutral, the idle drops to a normal idle speed after a few seconds. Then one can put it in gear without being on high idle. It also seems to take care of the car wanting to run at such high RPM's when the blue light is on. This has been my experience the past couple of times.

Thanks for this tip. Works on my 21 Crosstrek and the wife’s 16 Impreza.

 

[JRHAWK9]

Thanks for this tip. Works on my 21 Crosstrek and the wife’s 16 Impreza.

Awesome. I've been doing it all the time now since I discovered it.