[Blank]

my friend is an idiot... he filled up his bike with 10w 40 full synthetic motor oil, but needed abouyt 1/2 a quart more... so he topped off with 20w 40 dino oil!

does he need to drain it all and start over with new oil/filter, or is he OK? he already rode about 100-150 miles on the mix... i told him to drain and re fill the oil, but we are having rain for awhile so i figured i'd get some other popinions as there is no rush...

 

[Bror Jace]

Nope, no need to drain and refill. All motor oils (those designed for use in gasoline engines) are compatible.

That's not to say that there's any advantage in mixing oils (i.e., you're not likely to produce somehting 'better' than an actual blender), but no harm in it either.

Same goes for switching back and forth. You'll probably get the best results from using one oil and sticking with it for a while, but there's no harm in switching.

Anyway, in the past several years 'synthetic' has become more of a marketing term rather than a technical one. Most 'synthetics' on the market are actually highly refined (hydrocracked) mineral oil.

20W-40? Where'd you get that stuff?

 

[asleepz]

Ahhh you can get 20W-40 usually anywhere. I used to use it when I sold my old 87 Sentra back when I was 13 to keep it from smoking. Worked quite well too.

 

[Bror Jace]

"... you can get 20W-40 usually anywhere."

Don't you mean 20W-50? I've heard of some marine oils in 25W-40 or 20W-40 ... but have never actually seen any.

 

[Jarek]

Ahhh you can get 20W-40 usually anywhere. I used to use it when I sold my old 87 Sentra back when I was 13 to keep it from smoking. Worked quite well too.

haha i so agree! did the same thing with a car with bad piston rings