v_man

OK , maybe asking this question in the middle of summer is bad timing , I'm referring more to warming up an engine in the cooler months...

Around here , morning temps (6am) from about Nov. to March are anywhere from 30 - 45 degrees . So I will start my 90 'runner and let it idle in the driveway for about 5 - 10 minutes before I leave for work . Now one caveat :

I have an extremely short commute , about one mile to work . Part of my thinking in letting it warm up is that if I get in and drive to work , my engine would often go days without ever reaching normal operating temps .

What's your thoughts ? Idle your engine , turn the heart on so it is nice and toasty when you get in ? Or screw it , just hop in and drive it like you stole it in the morning ....

rworegon

All that warming up in those temps is wasting gas, IMHO. In similar temps, I start it, get situated, drive normally to work (2.5 miles) without hot-roddng it, and then take it for a longer spin every week or so.

Resto-noob

iTrader: (3)

That's not cold by my standards. If you must, take it for a longer drive before work, rather than letting it sit. I only let my old cars warm up for a minute or two tops, and that's in twenty below weather.

catfish21

iTrader: (1)

I have a 82 4by and my manual says for warmer temps let it tun for ten seconds and colder temps let it run for 30 seconds but I usually let mine run for about two mins just cause its so old I want it good and lubed when I roll out

CJM

I always let my vehicles warm up for a good 5-10 mins before leaving if its cold out. Every single vehicle has lasted for a LONG time. Is it really wasting gas, IDK...its working for me however.

rworegon

FWIW, my 95.5 Tacoma 5vz-fe manual says to warm engine up 10 seconds under normal conditions and 2 minutes when temperatures are below freezing before driving.

StewsRunner

iTrader: (1)

I usually let it sit just so it is warmer when I hop in, the windshield is defogged and so overdrive kicks in quicker.. I think in reality you just want to wait long enough for the oil to circulate which takes seconds, like Oregon said.. I've sat in the truck while letting it warm up and there is a point where I can hear the idle drop slightly, that is when I usually go..

wyoming9

iTrader: (1)

In the winter it does not get cold here only a few days below zero F

My routine is pretty much the same pull vehicle out of my lawn shed close over head door from inside .

Go tend to the fire one last time walk back turning lights off as I go go out the man door and leave. I go the long way to work about 5 miles.

This is with gas engines The 96 F250 7.3 does warm up more in the winter because it lives outside.

RSR

The only reason you need to let your engine warm up is to ensure that your oil is properly flowing before placing it under load. Head over to www.bobistheoilguy.com and read up. I found it fascinating. Basically, with oil the first number (10 in 10w30) is the oil's viscosity at air temperature, while the following number is the viscosity at operating temperature. Except for slowing oil leaks (e.g., you have an oil leak that leaks all the time even when the engine is off), you really should run the lowest first number you can get away with. 0w30 instead of Toyota's recommended 10 for instance. I run 5w30 synthetic all year just because it never gets too cold in central Texas, but if I lived where it got below freezing for more than 2 weeks, I'd go with a 0w for at least the winter months...

Also, if your commute is short, definitely make sure you run your rig for at least a 30 minute trip a couple times a week. Those short trips lead to a lot of moisture build up which will rust out your exhaust and also doesn't really allow your cat to heat up and burn off the combustion byproducts.

RSR

* the motor oil university series: http://www.bobistheoilguy.com/motor-oil-101/

derockus

iTrader: (1)

at the very least i let my engine warm up til the temp gauge just starts to move. i got a 22RE thats been rebuilt in the last 3000 miles. i wanted to make sure i always drove it it at operating temperatures for the first few thousand miles. i have a short (3.5 mi) commute too so, again, driving at operating temps. and in the winter i definitely let it run for 5-10 before i hop in the cold and drive it. helps the transmission warm up too for smoother shifting.

i think the "wasted gas" would be out matched buy the value of always running your engine at the temp it likes to run.

SPARKS89

iTrader: (1)

Does it really get that cold in New Hampshire?

v_man

Thanks for the informative responses . I also read that putting the T-Case in neutral and putting the transmission in 1st gear helps warm up the transmission , and therefore smoother shifting right out of the driveway .

I tried this and it does seem to work , for whatever reason it is like there are rocks in my trans. when it is cold , very stiff shifts at first .

derockus

iTrader: (1)

Even if the transmission is in N and the clutch is un-pushed the transmission internals are spinning and thereby heating up the oil. No need to do that transfercase N "trick".

v_man

...good to know .

Punchy

about 30-45 seconds and then I am coasting down the hill.

Resto-noob

iTrader: (3)

Double digits below zero isn't rare where I live. Ponds are usually frozen by New Year's, and the ice stays until April. Thirty degrees is really nothing when it comes to cold.

RSR

Synthetic fluids are your friend for cold starts. With fluids, it's always about viscosity, and synthetic fluids are more stable at both high and low temperatures.

As most of us regulars on this forum are attached to our truck, synthetic fluids will keep you running well past regular engine/tranny life.