synthetic oils and blends with synthetic and petrolium oil

> chickenlover, 3/31/2007,7:41:35 PM, wrote:
>
>> does anyone know of a good sourse of the tecnical differences and real
>> benifits of these over traditional car oils?( I aready know what the
>> dealers at toyota and subaru are saying, I own one of each 2006
>> tacoma and 2007 outback

There are clear benefits of using synthetic oil in terms of reduced engine
wear, longer change intervals (but do not exceed manufacturer warranty
requirements), slightly better fuel economy (one or two tenths of mpg),
reducing the likelihood of sludge (in engines that are susceptible to
sludge), and easier starting in cold weather. If you plan on selling your
car yourself (instead of trade-in), you will likely get more money for the
car if you can document your synthetic oil changes.

If you use conventional oil and change it every 5000 miles, and you plan on
trading in your car after 3 years or less, then the benefits of synthetics
are less clear.

I you change your conventional oil every 3000 miles, or plan on keeping your
car for 6 years or more, or plan on selling the car yourself, then using
synthetic oil with 5000-6000 mile change intervals will provide substantial
benefits over conventional oil at little or no extra cost.

IMO, in the 21st century (please ignore those 20th century oil studies often
quoted on this forum), synthetic oil is an absolute no-brainier.