I would only use it in the saab or the pathfinder.
The other engine are viscosity sensitive due to the VVT cam phasers and light reciprocating components AND oil cooling requirement.
My Subaru FB engine didn't really like a thick 5W 20 grade in it during the summer
This is tried and tested, not sitting around a keyboard just guessing
In the summer time, there is no way a 5w-20 would behave differently than a 0w-20.
Here we go with blanket statement again with no data or experience.
I just TOLD you it did.
I drove the car, ride in the car on trips an I noticed the difference. It was easily drivable, but didn't rev as eagerly, a little bit sluggish - but quieter running when hot.
Are you aware that Japanese 0W20 are directed at fuel conservation and high efficiency? Moreseo than 5W?
They tend to be formulated closer to the BOTTOM of the 20 grade range. whereas 5W20 are near the TOP of the 20 grade range.
Suabru idemitsu KV40 is ~ 37 cSt
KV100 is ~7.8
Here is (plain vanilla) Mobil 1 5W20
Viscosity @ 100ºC, cSt (ASTM D445) 8.9
Viscosity, @ 40ºC, cSt (ASTM D445) 49.8
Viscosity Index 160
Recall that this engine oil temp runs well below boiling; Around 77C