Here on the boards all I ever hear about is Moble1 syntheic oil. I know it's good sutff cause I've used it on my 1911s and Glocks for a couple years.
But arround here it's 28$ for 5 qts, bigt time expensive!! And Castrol synthetic oil is is 21$ for 5 quarts. I have run Castrol oil in alot of cars and trucks over the last couple decades and Castrol has proven itself as good of an oil as one could ask for.
So my question is, is anyone useing the Castrol synthetic oil in their Harley V-Twin motors and if so hows it doing for you?: Or has anyone heard any negrives about Castrol and Harleys??

 

the only negative I can think of is that Castrol is not formulated for an air cooled engine like a Harley which operates at extreme high temps and mobil1 v-twin is. Amsoil is the best oil on the market for harley air cooled engines and is a little less than the prices you mentioned. just make sure you are getting motorcycle oil and not the stuff for cars. The chemical composition of motorcycle oil is different than oil engineered forfor water cooled cars. check out the link below your post which appears everytime the subject of oil comes up.

 

I don't run Mobil 1 V-twin 'cause I had it analyzed and there wasn't enough difference between it and the Mobil 1 15w-50 car oil to justify the price difference. The "formulated for air-cooled engines" is more sales hype than substance.

I run Castrol Syntec 20w-50 in my bike on occasion, and run it in all my cars, too, but the 5w-20 stuff there. It is a Group III synthetic, meaning it is a hydrocracked petroleum-based product, and not a Group IV 'built from sctatch' synthetic. It's a good oil, and it'll do fine in your bike.

 

Hay Mack, your Glide and my Glide look almost like twin brothers ecept for the tank sticker. Mine is a 1999 Classic.

 

I'm using the mobil1vtwin.......runs good.

 

the 5 quart jug of the 15w-50 Mobile oil is $20 at wallmart.