might try that route with the 60w
summers here get pretty hot... 90s and up..with heat index's close to 100.... humidity gets high also
and im in a good bit of stop and go mild traffic

20/50 is great for spring and fall , but summer i can tell a difference motor noise and stop and go traffic

 

I’d still consider 50wt and that year be very sure to warm her up decently before taking of the avoid the usual base gasket leak, they didn’t get that squared away till after 93. Pre 92 bikes had a bit different breather & gasket arrangement, made them a bit sensitive to oil issues sometimes.

Philly ain’t that hot I’m from Baltimore originally.

 

I run 25w-60 dino in my '89 Evo Spotrster in summertime. I installed a pressure guage and on a hot Mid-Atlantic day that guage is on damn near zero when sitting in traffic.

 

It aint nice weather in phila by any means. It was 93 last week for a few days
and its going to mid 90s later this week stop and go traffic is brutal heat wise.
i ordered 3qts if dino 60w. Ill mix 20/50 and 60w half and half and see how she does

i have a pressure gauge as well. She gets low when its a hot day. I know evo’s have low pressure at idle but. Id rather mix the 60w with the 20/50 and see if its better.
both are dino oil. So im good mixing. Will see

yeah i warm her up well before leaving always do.

 

Humidity is what screws you guys over, remember that **** well. Good luck.

 

Yes and for my M8 to boot

 

I’ve run 20w50 all over the country…..never an issue. The oil pressure was low on a hot idled engine, but nothing abnormal.

 

Oil pressure gauge on an Evo will show next to zero when engine is hot.

20w50 is all an Evo needs.

 

Oil system pump is a volume pump over a pressure pump. It may get noisy, but it's still lubricating as it should.
I'm a 20-50 winter and 50w summer guy here in Houston running an oil cooler. 75-80 mph and still 178 in the bag after hours of it.
Use a good 50w synthetic and you'll be golden.. Unless it starts leaking around the old gaskets.. LOL.

Griz

 

Thanks for the thoughts guys. Bought the [evo] bike recently so the Twin Cam is sitting. I have always used 20w50 Castrol gtx going back to my Shovel head days. Nowdays I use 15w50 Mobil 1 full synthetic. But that real hot day on the evo with miles on it got me thinking 'cuz it's kinda noisy. Now I am wondering if the cushioning would be better with the dino oil but the heat dissipation with comment has got me thinking even more cuz I always overthink everything. I need a hobby. Oh yeh, this is it .....