So my dad has a big 10L bucket of auto grease at home, thats non synthetic and so has lasted for the past 20yrs. The question is, would i be able to use this for greasing certain parts on my bike instead of normal bike grease?
cheers
Definitely. We’re talking things like threads, hubs and BBs though, right? Not the chain?
(Also, don’t mix greases. Clean the old grease out before regreasing.)
considering the RPM and loads that car wheel bearings, CVs etc go through, I’m pretty sure auto grease will be fine on a bicycle 
Weather its (really) synthetic or not has nothing to do with shelf life, check for oil bleed and thickener separation. It should be fine and +10000 on not mixing greases. mixing thickener types can make grease go very runny or crusty in a hurry.
Haha I got some Castrol High speed bearing Grease for the headtube and bottom bracket, and i swear I can ride faster. lol
well when my dad bought it, it cost about $400 for the 10L so its a good quality grease and plus he use to be a mechanic so he knows what hes on about.
and yeah im talking bout bb, threads etc, i have another lube for the chain.
Cheers everyone, just wanted to double check to see whether it was alright, thought maybe it was thiner or for some reason wouldnt work
Spittin on the chain tends to make it go round faster.
I use valvoline grease and it works fine for wheel, headset and bb bearings. I only used that in the first place because bike grease, like so many other bike specific products, is massively marked up. I got 500ml for $10 compared to similar price for 50-100ml
does it say what particular kind of grease? eg lithium, HTB etc?
should be fine but probably not the best to use inside hubs as it may be too thick
i used automotive grease when i regreased the bearings on my bmx, but that is a piece of crap so i didn’t really care
i used some 20+ year old auto grease last week and its doing fine