Do I need to let my vehicle warm up when it's cold???

This question may seem irrelevant to you....either you already know the answer or you've never thought about it.  Let me tell ya, the weather here in San Diego has finally showed that it IS actually winter, haha.  With the nighttime temperatures dipping into the low 30s overnight in the foothills and valleys, you may have noticed some lovely "white stuff" on the ground.  Oh yes, it has been very frosty out in the early mornings.  If everything else if frosted over, it is safe to say that your vehicle will be also.  I went out the other day to leave in a hurry.  I couldn't even open my door...my Jeep was frozen shut :-0  Basically the entire vehicle was frozen.  I managed to grab the house, turn it on and guess what?  It was frozen too, burst open halfway down the house.  But I was in a hurry so I used that half hose to water down and de-thaw the door and windshield.  I would definitely suggest giving yourself some extra time to worry about the exterior of your vehicle in the early mornings for visibility. 
Now to the main question or point of this post.  Do you need to let your vehicle warm up during cold weather?  This is not as simple an answer as it would seem.  It really depends on what type of engine your vehicle has.  For your modern day, fuel injected, gas engine there is no proof that letting it warm up for 5 minutes before is better for your vehicle.  In fact, some would say that it is worse on the internal components.  This is because with the modern internal combustion engine the fuel injectors produce an excess of fuel into the combustion chamber, which can cling to your cylinder walls.  Since gasoline is an excellent solvent, excess gas on the walls can dissolve the oil that lubricates your cylinder walls, leading to shorter life.  It is recommended to give your vehicle a minute and then start off with easy driving.  The modern gasoline engine is very efficient, but this minute of warm-up gives the thick, cold oil a chance to start the journey up from the oil pan and start to lubricate the internal components. 
The recommendation is a bit different for a diesel engine.  Diesel engines are not  "start-up and go" machines and therefore need a warm-up period.  The warm up period depends on the ambient temperature outside.  So for here in San Diego, since we've been seeing the temps dip into the 30s, we recommend allowing your diesel engine warm-up for about 5 minutes.  Keep in mind that as with the gasoline engines, you will still not reach operating temperature without being driven.  

Now if you are an old car enthusiast and really enjoy that carbureted vehicle of yours, the answer is a resounding Yes! let that baby warm up for at least 5 minutes.  This gives the carburetor time to wake up and for oil to really get through and lubricate all the vital components.  When the engine is cold, the combustion is un-even and poor; the carb chokes off some of the air to compensate and runs richer, but less efficiently.  Once the vehicle is warm the fuel can vaporize properly, and the car will start to idle and  run smoothly. 

As always, take a look at your user manual for the factory recommendation first.  No two engines are exactly the same so figure out what yours likes ;-)  If you have any questions, please give us a call at 619-562-3933.   

---