http://autos.yahoo.com/articles/auto...ar-care-myths/

 

Yea...I read this in consumer reports.Too bad people buy into myths...they could save themselves a lot of money in the long run.

 

I'd still hate leave oil in for 7500 miles. That seems like an AWFULLY long time IMO

 

I change it every 5000 miles. Just for peace of mind.

Even the Ford dealership puts the next oil change at 3000 miles rather than going by the recommended interval when they put the sticker in the window. I suppose they are just looking to make more money though.

 

I was out to 5k oil changes on my F150 when I had it but I was also racking up 3k in about 6 weeks for a while so I was spending a ton of money on oil changes during the course of the year. On my F350 I am 7500 and since I am not traveling as much it takes me about 3 to 4 months before I change the oil now. Most of those are pretty much common sense but good advice none the less.

 

I change my oil every 2,500 and I let the engine warm up before I drive it. In the summer I let it sit until the idle drops which is EXACTLY 1 minute. In the winter, depending on how cold it is outside I let it run from 5-10 mins.

 

Myth: Let your engine warm up for several minutes before driving.

I saw someone at work doing this when they left Wed night. People just don't know, they hold to the old belief, which may have been valid at one time. I would not say anything to them unless they asked first, and even if they did ask, I know they will stick with what has worked for them for many years. I have noticed that the more knowledge people have of engines, the easier it is for me to explain how this myth causes more harm than good.

My favorite story is Zig Zigler's story about cutting the end off the ham before cooking it.

 

It's realy easy to get through these concerns. All you need to do is have an oil analysis done on oil run in your truck for 7500 miles. Then find someone to interpret the numbers for you. The best part is that if your results are good at that OCI, then the test is as good as free.

 

What harm can it do?

 

There is no harm to it. Just wasting fuel. I don't let my truck warm up because it doesn't warm up when it is sitting. Warms up quicker when I drive it right away.

 

It is good however for it to idle for a min or two to before driving off to make sure oil pressure is stabilized and the engine is lubricated.

 

Yep, takes less than 30 seconds for the idle to drop.

 

You get more blow-by when you idle an engine when the rings are cold. Rings are engineered to use the pressure of exploding gasoline/air mixture to push it out against the cylinder wall for a better seal. Rings are sized to take expansion into consideration as they heat up to operating temperature. The bottom line is that a little more pressure, from normal driving conditions, will allow a cold ring to seal better. Blow-by contains water and unburned fuel which degrade the oil's additive package, and carbon deposits which collect in ring grooves and eventually interfere with normal ring movement. The real harm comes from carbon build up in the ring grooves, as the engine ages, preventing the rings from maintaining a good seal resulting in an increase of blow-by gasses and more carbon deposits. It's a vicious cycle.

Thanks for asking.

 

^ which is why they say excessive idling is considered extreme conditions for engine oil changes...

 

If you all live in a place where it gets real cold in the winter and your truck is parled outside you'll see why you have to warm it up. Half the mornings I get into my truck I can't see because of frost on the windshield