Didn't Mark Whatley comment on this in Toyota Trails? His take was the heavier the better for the 2F, except in extreme cold. I run 20w-50 all summer and 15w-40 Delo 400 in the winter in my two 2F engines. These are "old school" motors and running "old school" viscosity makes sense to me. I have the owners manual from my '76 that reccomends 20w-50 down to 20F. It never gets close to that cold here so I could use 20w-50 year round. Honestly, though, it probably doesn't matter that much.
[quote author=Cruiserdrew link=board=1;threadid=14279;start=msg135170#msg135170 date=1081441324]
it probably doesn't matter that much.
[/quote]
I don't think so either. As far as I'm concerned, run 5-30 WalMart year-round. Just change the oil and filter often (and with WalMart oil/filter, it couldn't be that expensive every 1k miles)
I have the orig F engine in my pig and I run 15W-40 all year round as advised by a local 'cruiser guru'. According to the manual it certainly matters what temperature climate you live in-if that matters to anyone. Seems to work great.
[quote author=CruisinGA link=board=1;threadid=14279;start=msg136263#msg136263 date=1081567969]
Also cut waaay down on the amount of black gunk the exhaust spits out.
[/quote]
Why would the oil viscosity affect your exhaust? You have a head gasket leak?