[Vwdiesel] More on Synth

[Sandy Cameron]

I have run 5-50 synth from CanTire all winter in the 87 jetta, with great
results in cold starting, lots of pickup, (turbo spools quicker) and just
"sporty" performance.
Clean running too- just passed it's first emission check at 425,000km.

Questions:

What does the Vis spread mean in synth? in dino juice, it would be a no-no,
too many long chain polymers.

I have a jug of 10-30 synth I thought of putting in for the summer, is the
top (30) number as heavy for hot weather as the 5-50.

Not sure which would be better for hot weather

What does the reduced vis spread of the 10-30 indicate in synth?

Sandy