Remote Start/Cool Down Timer & effect on MPG's?

[SHyans]

I have a remote start that I use just about every morning that shuts off in about 10 minutes. I've also been thinking about a cool down device (see Turbo Cool Dwon thread).

I'm wondering about how much my remote start contributes to my lousy mpg's and how much more a cool down timer would contribute.

As it stands now, I just WAIT for my EGT to drop below 300.

Anybody got any idea?

 

[rbattelle]

If you're idling 10 minutes every morning, then your fuel economy is suffering big time. How bad is your economy?



Are you letting the truck warm up for 10 minutes every morning before driving it? If so, are you turning on an exhaust brake during that time?



-Ryan

 

[SHyans]

My city mpg's are 12-13 mpg and I can't help but wonder if it is the 10 minutes of idling every morning that has my city mileage so low. Getting 17-18 highway. Temps are around 20-30 degrees so I don't want to just jump in and drive off.

No I don't turn on an exhaust brake. Just push the button and she fires up after about 10-15 seconds.

Am I making a big newbie mistake with regard to the exhaust brake? See them in magazines but not sure what they do.

Thanks for any "insights" Ryan.

 

[LOtero]

good question, i have the remote start and turbo timer installed and even though i am not incredibly concerned with my mpgs i am curious on what kind of effects they have. as for the warm up time, mine is set for 12 minutes and i usually let it warm up that long just because i dont like the idea of just jumping in and driving away. is this a bad practice? would i be better off warming it up for a minute or two?

 

[rbattelle]

Okay, what I'm about to say is my opinion, based on my own independent research [I say this because there may be people who disagree with me - and that's fine].



I believe it's poor practice to idle the engine to warm it up. I think it's a bad idea with gassers too, but especially with a diesel. At idle, your fuel/air ratio is very very low (I've heard as low as 100:1). With so little fuel being injected, you're really not generating much heat at all. All that time you're sitting there idling, a significant portion of what little fuel you're injecting isn't even burning - it's washing down your cylinder walls and leaking past your rings into your oil. The cylinder washing can clean off any beneficial lubricating layers on the cylinder walls, and it's not good to have diesel in your oil. I'm not sure which effect is greater. Also remember that at idle your oil pressure and flow is minimum. In fact, Cummins specifically forbids idling the engine longer than 5 minutes before break-in.



I asked about the exhaust brake because using one is a way to prevent the aforementioned problems. Another way is to idle the engine up. Now, it will idle up to 1000 RPM on its own, but some people (myself included) don't think that's high enough in really cold temps. With an 04. 5, you should be able to manually high-idle the truck using the cruise control buttons. 1200 RPM is a good choice, in my opinion.



I'm not trying to make you paranoid! Some people idle their engines for long periods of time and never have a lick of trouble. I'm just giving you reasons you might reconsider. Personally, I believe in idling the engine for 2 minutes (until the grid heaters have finished cycling), then driving easy (keeping RPM below 2000) until the engine has warmed up.



Now, SHayans, I actually think your mileage is pretty good for an 04. 5! Lots of people are struggling to get 14-15 on the highway. Think how much better it would be if you cut out all that idle time.



Please, if I've said anything exceedingly stupid someone correct me...



-Ryan

 

[Tryingit]

I also have the remote start and the turbo cool down. The turbo cool down is going to be part of life. So I won't worry about the effects of using that feature. I don't use the remote start often. On my old gas truck i use the remote more often. It does have a serious effect on the mileage.



If you want to see how many hours are on your truck turn the key on (truck not running)push the trip/mileage button approx. six times and then hold the the button in. The number of hours on your engine will display. Mine are at 307 hours with 10,219 miles. I have a total of 33. 28 miles per hour logged. Not bad, could be better. just divide the mileage by the # of hours shown on your hour meter. Oo.

 

[rbattelle]

If you want to see how many hours are on your truck turn the key on (truck not running)push the trip/mileage button approx. six times and then hold the the button in.

You only have to hold the button depressed for 6 seconds... no need to press it 6 times then hold.



-Ryan

 

[bpenrod]

Long idle periods never seemed to hurt my mileage too bad. By long periods I'm talking 2 to 3 hours with the truck going up to 1000 rpm's as needed. I reset the hours on the overhead at every tank and when the weather is really cold I can be down 4 or 5 hours per tank. I've never really noticed more than a three mpg drop on those tanks. Usually around 20 to 21 mixed driving and a low of 17. 5 to 18 when in the single digits and it idles long.

 

[DDT]

With an 04. 5, you should be able to manually high-idle the truck using the cruise control buttons. 1200 RPM is a good choice, in my opinion.







Will this work on my 03????

 

[rbattelle]

With an 04. 5, you should be able to manually high-idle the truck using the cruise control buttons. 1200 RPM is a good choice, in my opinion.







Will this work on my 03????

I don't think it can be done on 2003 trucks... only 04. 5 and up.

 

[SHyans]

I've often noticed it takes a couple of miles before my heater warms up. I thought that was strange considering it had been runnng for 10 minutes or so. Ryan's comments about the truck not generating much heat while idling seems to explain that. I do drive like a granny until temps rise to normal.

I am going to lay off the remote and see how it impacts my mpg. I notice my overhead mpg readout will lower a few tenths from the day before after a morning idling session.

I am freaking out about mpg's because I can't believe the fuel prices lately.

Ryan, I did a search on exhaust brakes and there was some stuff about higher EGT's associated with them. Any feedback on that?

Thanks again.

Steve

 

[MMead]

I used to always warm up my old cars until I read a book called "Drive it Forever" a while back. The book said idling a cold engine was one of the worst things you can do to a motor. The book said to only wait 15 seconds in the summer and 30 seconds in the winter, after the oil pressure goes up before shifting into drive, (and that was more for the transmission that for the engine. ) That being said, the book highly recommended driving like a granny until the temps got up to normal, and more importantly, never lugg the engine when it's cold. If you don't put the engine under LIGHT load, it will take forever to get up to running temps. While the engine is cold you get the most wear, the most deposits, the least protection from your oil and fuel in places it's not supposed to be.



"Drive it Forever" was mainly about gas engines, but I think the princples are similar for diesels when it comes to warm up -- In my opinion.

 

[rbattelle]

MMead - great post! I have 2 copies of that book on my bookshelf (I'll sell one to anyone that wants it).



Steve, if you engage an exhaust brake at idle and leave it on it will indeed raise EGTs, but that's exactly what you want to happen. Gotta get the engine to generate some heat. Certainly having an exhaust brake won't harm your engine at all, and any increases in EGT at normal cruising will not be enough to cause any harm. But I would advise you not to get an exhaust brake if all you need it for is to keep the engine warm at idle. You really only "need" one if you tow heavy (more so if you tow in the mountains). Best thing to do is just idle until the grid heaters shut off (2 minutes), then drive easy just like MMead said.



-Ryan

 

[SHyans]

Ryan & MMead... . you guys are great.

A friend told me to wait until my oil pressure reaches the usual reading before I drive off. That's usually happens a lot quicker than two minutes.

My remote starting days are over.

Thanks MUCHO!

 

[Pilotman]

How do you get that idel up with the cruise control?

 

[rbattelle]

How do you get that idel up with the cruise control?

The dealer has to enable it. Remember, it's only 04. 5 and up...



-Ryan

 

[SHyans]

Follow up....

Since I posted this a few weeks ago, I've only been allowing my truck to idle for 2-3 minutes with the remote start as opposed to 10 minute or so (sometimes I'd restart it after it shut down!)

Under the similar driving conditions, I am now getting a strong 1+ increase in mpg (hand calc ... . overhead is on crack since TSB).

Now I drive like a granny til engine warms up.