Warm Up or No?

[cee]

How much warm up, if any?

..wondering what everybody's thoughts are on the proper amt of time to allow your veh to warm up..especially with the winter months here (though i'm in TEXus, so our winters aren't horrific just a mite chilly..hehe)..

..still, is there some benefit to allowing a few sec.s or min.s to warm (beyond defrosting things)?..or not?..

..lately, i've been just start-&-go; no warm-up time at all..but i wonder if that's bad on the engine and/or worse on mpg..i notice my RPMs are a tad higher, but T'Pal also seems to coast faster without need for acceleration (due to higher RPM'ing, no doubt)..i can cruise out of my cul-de-sac without any gas pedal-pushing..

..any sugg's or philosophies would be welcomed!..

[Pontiac]

Myself, if I were to do a warm up, it'd be long enough to just brush the car off (And take my time doing it. ) or allow enough heat to warm up the windshield so I'm not using my glove/hands to wipe it down. (Pet peve of mine is seeing the streaks left)

Outside of that, I hop in the car, start the car, put the belt on, put 'er in gear. The car actually does warm up faster when the engine is under load anyways.

[VWJunky]

Once again depends on the car, in my car it states in the handbook to not let it sit there and warm up. Actually it takes longer in my diesel. VW sugests that to start it up and drive off slowly untill it warms up.

I would just check your owners manual.

But of course i would love to have a remote start to warm up the car before i took off but I can't with a 5speed manual. LOL!

E

[rem83]

I would suggest that generally your car doesn't need much time to warm up. I live in Houston, so my winter temps are probably even higher than yours, but even in winter I generally only allow about 10 seconds to warm up. Back when I lived up north, I'd give it maybe 30 seconds to a minute, but nothing major.

HOWEVER - Until your temperature needle comes up a significant amount, drive your car gently. I generally try to keep the tach under 2k rpm, or 3k in my Miata. While 10-30 seconds of warmup time were more than enough to get oil flowing everywhere, things like camshafts and other parts of the drive-train have not reached operating temperature and clearances are not at the operating spec (thermal expansion causes clearances to change). While it is ok to drive like this, there is increased load on some parts, so you want to drive gently. Usually after about 5 minutes of driving gently, you can get a bit more aggressive, but again this will be dependent on your specific car and driving conditions. Do not be one of those *******s who just turns there car on and immediately revs it to 5k rpm (of course since you're on fuelly, you're probably not going to be doing that anyway).

[DrFranken]

Warmup? I'm nearly to the end of my driveway before my engine is even running! OK That's the Prius system making things ready to start while the electric motors roll me toward the road! Truthfully, though, if you don't need heat to defrost/defog the windows put it in gear as soon as it's running smoothly and the oil pressure is up. In any recent car that should be 5 to 10 seconds.

While standing still you get 0.000000 MPG! You should do everything more slowly and smoothly for for the first several minutes until things warm up and this helps shocks, breaks, springs, transmissions and other components too. Certainly your engine will warm much more quickly under the light load of easy driving than it will in idling and you're getting somewhere with the fuel you're burning.

[bates]

Most modern cars are hurt more than helped by a sitting warm up. Modern engines build acid when they are allowed to sit and idle cold, acid is not good for your engine. Like VWJunky and rem83 point out, a nice gentle driving warm up is optimal unless your specific owner's manual says otherwise. You are correct that your idle speeds will be higher until your engine warms up, that is part of the computer system for a modern fuel injected engine, in older engines we had a choke in the carburetor which would have a similar effect on the high idle. Generally speaking once your idle speed returns to normal your temperture gauge should be indicating in the normal range too, and then you can begin your normal driving habits. I like the suggestion of keeping the RPM's under 2,000 to 3,000 until the car is warmed up, that sounds like solid advice to an old wrench bender like me. For the record in one of my jobs I would from time to time be forced to esentially floor and ice cold engine and it always made me cringe to do it. That was working in Emergency Services where I'd receive the radio equivilant of a 911 call and have to slam a Ford Crown Victoria Police Interceptor model into gear as soon as the engine caught and roar off. It was the job, and those cars had very limited lives many suffering catastrophic engine failures long before their usefull life should have ended, but again that is what happens when you mistreat your engines like that.

If you warm up your engine gently by driving easily you should expect years of faithful service from your car's engine.

[AW11ERIC]

It really depends on the car, as others have said. Newer cars seem to require less time to heat up, and the cold-idle RPM is hardly offset from the warm-idle RPM.

With my MR2, I let it sit at least 5 minutes in the morning to warm up a little. My reasoning is it has 190,000 miles on the original engine and transmission, and it uses 20-25 year old technology as far as engineering goes. The seals and gaskets within the engine are more prone to failure, especially if they are exposed to high oil pressure before they are lubricated and expanded from the internal heat of the engine. The cold-idle RPM is also much higher than the warm-idle RPM, this may be due in part to the cold-start 5th injector that operates until the car has reached operating temperature.

I tend to use more gas driving to work without warming up the car, as I live RIGHT off the highway and I HAVE to go 60MPH+ as soon as I leave the parking lot of my apartments. By the time the engine is warmed up I'm nearly to work, and I have to shut if off again. The whole time I'm dumping extra gas during the cold-idle process, and probably causing internal damage to the engine going that fast as soon as I start up the car on a cold morning.

If you are able to drive slowly for a few minutes before you hit the highway, you're probably OK. And if your car does not idle exceedingly high while it is cold, then it is probably more fuel efficient than older cars that idled very high until they reach operating temperatures. Hope my posts makes sense.

[rem83]

Just wanted to add real fast, while this advice is good for cars, do not treat a motorcycle this way. Particularly on air cooled bikes, you should let them sit and idle until they get reasonably warm. Clearances inside the engine are more of a big deal on a bike engine, and it's pretty much impossible, and a bad idea anyway, to drive most bikes (v-twin cruisers excluded) at low-ish rpms while cold.

[cee]

..cool info & much thx to all..i'll continue to coast T'Pal from a cold start, per y'all's recommendations..i'm here to get good mpg, but i was worried this might be at the expense of my engine..nice to know that's less likely..

..and i'm sure it'll help others (in both sun belt & northerly climes (heh!)..

'preciate the feedback!

[tomnh]

With most newer cars having fuel injection, I just let mine run till the RPMs come down to 750RPMs. That is the normal Idel RPMs for my car. It also gives my Mark VII time to pump up the air springs and the Hydro brake system too.

There are many reasons that vary per car as to how long to let it warm up.

exception: If it is snowing or freezing rain. I will let it sit till it starts blowing warm air for safetys sake.