<p>Perhaps the best essay I’ve read on the Oil Change:</p>
<p>The 3000 Mile Myth
The 3000 mile oil change interval has been pounded into people’s heads for decades. It had a scientific basis when engines used non-multi-weight, non-detergent oil. It no longer has any scientific basis, but it is still being promoted by certain entities, most notably the oil change industry in the United States. This myth is also sometimes known as the “Cheap Insurance Myth.”</p>
<p>The 3000 Mile Fact
There are still vehicles that need 3K oil changes, but it’s not because the oil goes bad after 3K miles. One example is the Saturn S series. These vehicles have a timing chain system that is very sensitive to clean oil because oil pressure is used as hydraulic fluid to ratchet up the timing chain tensioner. If varnish forms in the timing chain tensioner bore then this system can fail and the chain will become loose and eventually break. Dealers have gone as far as tearing out the normal service schedule (6000 miles) and leaving only the severe service schedule. If your engine is destroyed (under warranty) by a failed timing chain then the dealer will legitimately request evidence of oil changes. Unfortunately this problem usually won’t manifest itself during the warranty period.</p>
<p>Oil change intervals with synthetic oil
Synthetic oils withstand higher temperatures before breaking down, and have more base stock and less viscosity modifiers. Synthetics wear out, become acidic, and eventually become saturated with suspended soot particles, just like regular oil. Again, an oil analysis is a good investment to determine the optimum oil change interval. Never exceed the manufacturer requirements for normal service. </p>
<p>Filter Change Interval
Back in the days of 3000 mile oil changes many manufacturers recommended filter changes only half as often because the filter did not become clogged with dirt at only 3000 miles. This was good advice back then, especially because with non-detergent motor oils a lot of the sludge remained stuck to internal engine parts rather than being carried in the oil to the filter. Nowadays the filter should be changed at every oil change. There are some people who believe so much in synthetic oil that they change filters without changing the oil. There’s no harm in changing the filter without changing the oil, but there is no point in doing this.</p>
<p>Quick-Lube (and dealer) Problems to Watch Out For</p>
<ol>
<li><p>SAE30 oil. Some quick-lube places have been known to offer advertised specials that use SAE 30 oil, as opposed to 5W30 or 10W30. Pay the extra for the proper oil, or better yet avoid merchants that try to pull this kind of thing because it’s an indicator that they are less than honest.</p></li>
<li><p>Trying to use the wrong oil because it’s what they have in bulk. Insist on the oil that is specified on your filler cap and in your manual.</p></li>
<li><p>Pumping the oil out through the dipstick hole instead of removing the drain plug. I came across this gem when I asked if I needed to bring my own copper drain plug gasket. They said that they didn’t remove the drain plug to drain the old oil. This was the Oil Changer location at Kifer & Wolfe in Sunnyvale, California. Pumping the oil out through the dipstick hole is a terrible way to get the old oil out because it leaves a lot of junk in the bottom of the oil pan. This was a long time ago and maybe they’ve changed their ways since then.</p></li>
<li><p>Selling unneeded and overpriced services such as engine flushes.</p></li>
<li><p>Selling overpriced, and often low quality, parts such as wiper blades and washer fluid, PCV valves, thermostats, etc. Never let a quick-lube place do any mechanical work on your vehicle… They do no use journeyman mechanics.</p></li>
<li><p>Using poor quality filters. You really want to bring your own filter, from the dealer, with you when you go to a quick-lube place. They may take $1 or $2 off the price if you do this but don’t count on it.</p></li>
<li><p>If you have a vehicle that actually still has Zerk fittings to lubricate then be sure that they actually lubricate these fitting. Most cars no longer require lubrication but some trucks still do.</p></li>
<li><p>Do not let a quick-lube place change or add any fluids other than oil. No transmission fluid, no brake fluid, no power steering fluid, no antifreeze, no oil additives, no fuel additives. It is just too easy for them to use the wrong fluid and cause permanent damage to your vehicle.</p></li>
</ol>
<p>For some horror stories about Jiffy Lube see:
<a href=“http://www.consumeraffairs.com/automotive/jiffy_lube.htm[/url]”>http://www.consumeraffairs.com/automotive/jiffy_lube.htm</a> .</p>