Went in to buy some straight 50 wt oil for my bike and my indy flipped out. He started arguing with me about how 50 weight oil was for shovels, etc.. It would "ruin" my evo... Its 80 plus degrees here and my 1989 owners manual RECOMMENDS sae 50 in temperaures above 60F and sae 60 above 80F. We've got 100 degree days coming soon and I plan on riding but, I feel like 20w-50 is too thin for those temperatures. Who is right?

 

You are. Find a new shop. Was he trying to sell you drag specialty labeled oil too?

 

I always ran straight 50w in the summer. Your indy thinks he knows too much.

 

Find a new indy.

 

I've been thinking about this myself. It's starting to get hot here in FLA. I think I may try the 50w in my '93 Heritage.

 

I figured as much. he usually keeps the 20-50 Harley oil that I use in stock so, I thought he would have some 50. Guess I have an excuse to ride to the dealer tomorrow. They have 50 and 60 in stock.

 

You're both right. 50 wt works as well as 20W50 in those temps. (btw, 20w-50 is not 'too thin'.)

 

Won't blow up with either, synthetic or not,
according to your chart there, you can't ride above 100

 

Just go to the auto store and get valvoline VR1 50 non synthetic. You'll be happy with it.

 

I thought about that but everything I have read says that that is a racing oil designed to be changed immediately after a race and that it breaks down pretty quickly. I dont know ... Ive been happy with the HD stuff so far.