I was reading an article in the local paper the other day regarding cold startup damage. It stated that starting a cold engine will put the most wear on an engine. I can't really remember why this is so, maybe something to do with cold oil being pumped right on back into the pan leaving some parts high and dry? Anyhow they recommended the use of engine oil heaters wether it be the simple dipstick type, or a pan heater or otherwise. From what I remember they also said to use not only in winter but through the fall and spring also. Well as I was looking through jcwhitney I found a dipstick style heater for $10. Since jcwhitney is going to stop sending me catalogues if I don't buy something soon I was thinking of trying it out. Are there any drawbacks to trying it? What do you guys think?
-Eric Reid '88 744 gle m47, '80 242gt, '90 745ti

Just use a high quality Synthetic like Amsoil (OK I sell the stuff, shameless plug) .
Regular oil thickens up when cold and does not circulate well through the engine. It also makes cranking harder .When it gets real cold the stuff gets so thick some engines will not turn fast enough to start ( especially diesels).

High quality synthetics don't have that problem and oil circulates imidiatly on start up. Heater not necessary ( my 224,000 mi. 240 diesel that would barely crank when 30 deg f out before I switched it over to synthetic,, now starts down to 15 deg f without any problem)
Oil filter with an anti drainback valve such as Mann , Volvo or Amsoil filters keeps oil in filter and allows it to pressure up faster. with cheap filter and regular oil , the oil drains back to the pan overnight and thickens up , if it gets real cold sometimes the oil pump will just spin without picking up any , or very little oil which is why sometimes on a cold start you will watch an oil pressure gauge just sit there for a while while the lifters rods and pistons clatter until suddenly it jumps up to partial pressure and then slowly climbs.
This is where the cold start damage comes in.

eric: that was supposed to read 'www.jcwhitney.com' but it didn't print out the first time.--PD.

eric; while the $10 price tag sounds OK, a 'block heater' might be more effective. Also, you can get the jcwhitney catalog on-line, so don't buy a 'so-so' purchase just to keep the paper-makers in business: just go to ---PD.

They're OK. SO are the magnetic ones that heat the oil pan itself.

The startup damage is really because the engine oil has largely drained back into the pan during cold starts. For that reason it obviously takes longer to circulate throughout the engine.

One thing that will help more than anything else, is to put a Mann or Volvo filter on your car. That's if you don't already have one. That keeps the oil in the filter and you get almost instant oil pressure. Otherwise (some other lesser filters) you get low oil pressure for several seconds.

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Chris Herbst, near Chicago, IL. 93 940, 91 240, 90 240, 88 740, 87 240