I got a few extra quarts of Motol 15/30 and 20/40 so i'm looking to combine them both to make one oil change good or bad idea?
I hate to waste the oil just because of the weight.
Also one is the semi-sythetic and the other is just regular oil.

15w-30 plus an equal part of 20w-40 will yield an exact weight of 17.5w-35.


http://www.r1-forum.com/forums/showthread.php?t=227298



I think 17.5w-35 will be ok.

I've heard a million times NOT to mix different weights of oil because they won't mix (one will float on the other).

although I can't remember ever doing it, I've always thought, what the hell does it matter if it mixes? it's all oil!

I'm sure my response will help you greatly! :lol

I've heard a million times NOT to mix different weights of oil because they won't mix (one will float on the other).




That is simply not true. As long as the oils that are to be mixed together are the same exact brand and type, it is perectly fine to do so. Mixing oils of differen't brands could have a negative effect as differen't manufacture's use differen't additive packages. The higher quality motor oil's start off with a more pure base stock before being refined into motor oil, resulting in less parrafin, (wax) meaning that the finished product will be less volatile.

Motor oil has improved dramatically over just the past 10-15 years, meaning that even conventional motor oil is almost as good as the synthetics. I think the biggest difference between brands of motor oil would be the additive packages, which is why you shouldn't mix differen't brands, but as long as the brands of the oils that are being mixed are the same, it is perfectly fine to mix weights. Like a manufacturer is going to change the additive package from a 10w-30 to a 10w-40. If the brand and oil type are the same, so is the additive package.

If you took a base stock 5 weight motor oil and mixed an equal part of 10 weight base stock. you would wind up with exactly 7.5 weight. All a multi-weight is, is a base stock (the first number) combined with VII's (viscosity index improvers) (the second number) Two differen't multi-weights of the same brand have the same additive package. The only difference between 10w-30 & 10w-40 would be 10w-40 has more VII's. The base stocks are potentially identical, (multi-weights of the same brand) and is ok to mix. It is also ok to mix syn with dino.




Lates :hellobye

I got a few extra quarts of Motol 15/30 and 20/40 so i'm looking to combine them both


Mix dat shiot homie, the one will be thankfull.

one is the semi-sythetic and the other is just regular oil.




Just saw this...


Are they both for motorcycles? Or is one for automobiles and one for motorcycles? Reason I ask is, automobile motor oil and motorcycle motor oil are engineered differently. Auto oil is engineered more toward economy, whereas moto oil is engineered for a much more extreme envirornment. They both have totally differen't additive packages. Moto oil has much more anti-wear additives such as zinc and phosphorous as well as additives to eliminate slipping in a wet clutch. Mixing the two could cause a problem, but you would have to ask Motul, cause I really don't know the answer to that.




On the other hand, if they're both moto oil....



Mix away!!!




:hellobye