During the discussion of synthetic oils I noted the weights of oil being
used.  My owners handbook for the 85  says straight 40W for running in temp
ranges of   temp ranges of  70F to 100F.  Multi grade 20W-50W is rated up to
80F only.  Since I'll be running in the summers on the hot tarmac of high dry
New Mexico and long distance driving into Mexico, where you can cook your
dinner if the traffic is not too bad, I've been preparing to use single grade
40W for summers and maybe 20W 40W for winter.  I'm aware of the cold
start/hot running issues viz a viz wear factors. I'd feel better about a
lighter oil with lots of start and stop driving.

I noted one comment about running cooler with synthetics.
Anyone know if synthetics might change the weight/temp reccommendations?

I'm interested in any thoughts, experiences or discussion on the topic of oil
weight and climate.
Bob
Corrales, NM