Stick with what you are using.  The high mileage oils are marketed
towards engines that are starting to smoke and have low compression.
Yours is probably not in that bad of condition.
TEMiller

Charles E Clement/FWF/EXP/UTIA wrote:

>We use Castrol GTX 20W50 motor oil in our 91 Westy.  I have noticed that
>Castrol has a "High Mileage" motor oil that they recommend for engines with
>more than 75,000 miles.  Is this a marketing gimmick or is this formulation
>actually better?  Our engine has 145,000 miles on it and we want to use the
>best oil to keep it happy for many more miles.  Your input would be most
>welcome.
>
>Charles, Susan, Nicolaus & Joshua
>91 Westy
>02 Protege5
>
>
>
>