I bought my 91 Westy new in May 1991.  Through much of the life of the
camper, I limited my top speed to 65 mph.   I have the stock setup with
no modifications.   I run Castrol 20w-50 exclusively.    As the miles got
up to 200,000 miles on the odometer I've limited my driving top driving
speed to 60 mpg because I'm slowly losing coolant and since I had my
clutch replaced the shop apparently couldn't get the engine seal replaced
correctly so there is an oil leak there.   Drove over 5K miles around and
across the country and made back to the Sacramento area with no issues.
The odometer is currently at a little over 253,000 miles.  Same stock setup.
Original engine with original heads never removed.

Others with different conditions will quote differently.

Steven
91 Westy

On Thu, Aug 31, 2017 at 10:41 AM, Dan N <dn92610@gmail.com> wrote:

> *-What kind of highway speeds do people feel comfortable in sustaining?*
> 60mph to 65mph
>
> *-What are preferred oil brands and grade these days?*
> I use this oil with Mann oil filter
> https://lucasoil.com/products/hot-rod-high-performance/hot-
> rod-classic-car-20w-50-motor-oil
>