Mixing different grades of oil? >> 20w-40 + 15w-40?

[tedrogers]

Hi,

My FZ6 manual states that one of the recommended oils to use is 20w-40...and this is what is in the engine.

Can I top up the 15w-40 as I have some of this lying around? It meets all the various specifications so will it be okay to use? The only difference is it will cope with slightly lower temperatures than 20w-40.

Can you mix oils of different viscosities and will my FZ6 complain or suffer damage? It is only 3 months old.

Thanks.

 

[blitzcraig]

You are going to find conflicting opinions about this. I think generally it's ok, the main gripes I have found are not to mix oils of different brands as well as not mixing synthetic with non-synthetic oil. Otherwise I think it's fine.

 

[RJ2112]

+1 on blitzcraig's comment...

As a really old guy told me when I was very young.... "some oil is better than no oil"

If I happen to have different grades of oil on hand when I change the engine oil... I'm not terribly concerned about that... if they are all within the range allowed by the manual, I don't see the harm.

Dino oil is a bell curve of different length molecules, which 'averages out' to the grade mentioned on the label. Some lighter, some heavier. You mixing in some stuff that is just very slightly different in characteristic (and still within the allowable scope) isn't going to do anything. Except lubricate your engine as designed.

 

[wrightme43]

wont hurt anything.

 

[danfree]

I sure hope it's OK. I know the manual calls for Yamalube 20w-40. The dealer had none when I went to get oil for my first change. They told me to use 20w-50. And that is what I have been using. I decided to try a synthetic/ mineral blend now that the engine has about 4000 miles on it. I live in Florida, so I can ride all year. I started thinking the 20w-50 was bit high for morning temps in the high 30's for Winter. I am going to use Motul 5100 for the next year. In the Winter I'll be using 2 qts of 10w-40 and 1 qt of 15w-50. In the Summer I will use use 2 qts of 15w-50 and 1 qt 10w-40. It is probably a bit eccentric, but it makes sense to me. I agree that it will be OK as long as you don't mix brands. But that is an opinion and I have no real experience to back it up. Ultimately, you can't go wrong by following the manual's specs. And obviously I am not. 10w-40 is also specified in the manual and it is available from all the oil vendors. I just feel Florida is too warm for too long to use it all year long. Though most of my research seems to show the 50 weight oil is geared for big V-twins and the 40 weight for smaller higher revving engines and such. The thing that sold me was Yamalube came out with a new synthetic oil in 15w-50, but it is too expensive! The 20w-40 isn't available anymore. At least not around here. The Motul isn't cheap, but it is about half the cost.

 

[TownsendsFJR1300]

I sure hope it's OK. I know the manual calls for Yamalube 20w-40. The dealer had none when I went to get oil for my first change. They told me to use 20w-50. And that is what I have been using. I decided to try a synthetic/ mineral blend now that the engine has about 4000 miles on it. I live in Florida, so I can ride all year. I started thinking the 20w-50 was bit high for morning temps in the high 30's for Winter. I am going to use Motul 5100 for the next year. In the Winter I'll be using 2 qts of 10w-40 and 1 qt of 15w-50. In the Summer I will use use 2 qts of 15w-50 and 1 qt 10w-40. It is probably a bit eccentric, but it makes sense to me. I agree that it will be OK as long as you don't mix brands. But that is an opinion and I have no real experience to back it up. Ultimately, you can't go wrong by following the manual's specs. And obviously I am not. 10w-40 is also specified in the manual and it is available from all the oil vendors. I just feel Florida is too warm for too long to use it all year long. Though most of my research seems to show the 50 weight oil is geared for big V-twins and the 40 weight for smaller higher revving engines and such. The thing that sold me was Yamalube came out with a new synthetic oil in 15w-50, but it is too expensive! The 20w-40 isn't available anymore. At least not around here. The Motul isn't cheap, but it is about half the cost.

5100 is fine.... Run it in all my bikes and I'm farther south than you...

 

[speedfrk]

I sure hope it's OK. I know the manual calls for Yamalube 20w-40. The dealer had none when I went to get oil for my first change. They told me to use 20w-50. And that is what I have been using. I decided to try a synthetic/ mineral blend now that the engine has about 4000 miles on it. I live in Florida, so I can ride all year. I started thinking the 20w-50 was bit high for morning temps in the high 30's for Winter. I am going to use Motul 5100 for the next year. In the Winter I'll be using 2 qts of 10w-40 and 1 qt of 15w-50. In the Summer I will use use 2 qts of 15w-50 and 1 qt 10w-40. It is probably a bit eccentric, but it makes sense to me. I agree that it will be OK as long as you don't mix brands. But that is an opinion and I have no real experience to back it up. Ultimately, you can't go wrong by following the manual's specs. And obviously I am not. 10w-40 is also specified in the manual and it is available from all the oil vendors. I just feel Florida is too warm for too long to use it all year long. Though most of my research seems to show the 50 weight oil is geared for big V-twins and the 40 weight for smaller higher revving engines and such. The thing that sold me was Yamalube came out with a new synthetic oil in 15w-50, but it is too expensive! The 20w-40 isn't available anymore. At least not around here. The Motul isn't cheap, but it is about half the cost.

If you change your oil every 3K miles and only street ride (no racing) you could use Crisco cooking oil and it would be ok. Just use any major brand name oil and you will be fine. I generally wouldn't mix different weights of oil unless you are just topping it off before you change it next time, though.

 

[macem29]

15/40 and 20/40 are likely the same base fluid, as long as you're not mixing mineral and
synthetic as discussed, modern multi-viscosity oil starts life the same way and the properties
are changed by adding different polymers (microscopic plastic strands) that change shape
when warmed thus altering viscosity, a higher rated viscosity oil will have more/different
polymers than the lower one but otherwise be the same fluid and there should be no mixing issues

 

[wolfc70]

You can mix oils, :noworries:

You can mix all types of oils, even synthetic, how do you think they get synthetic blends.

Amsoil states on their website that their oils are compatible with mineral oils, you just lose some of the benefits of running a synthetic. Even Motul and Redline POE ester oil can be mixed with conventional oil. Your bike will be fine, and as someone else posted, any oil is better than no oil.

 

[Tailgate]

If you change your oil every 3K miles and only street ride (no racing) you could use Crisco cooking oil and it would be ok. Just use any major brand name oil and you will be fine. I generally wouldn't mix different weights of oil unless you are just topping it off before you change it next time, though.

How about Blue Bonnet margerine---would that be okay if I ran that in my FZ6 crankcase? This won't affect the warranty...or will it?

 

[tedrogers]

Thanks to everyone. Awesome pool of knowledge there.

 

[RJ2112]

How about Blue Bonnet margerine---would that be okay if I ran that in my FZ6 crankcase? This won't affect the warranty...or will it?

Margerine is mainly water, and vegetable oil..... whipped to a froth. Take the water out of it, and you have something very similar to Castor Oil......

The post WWII basis of Castrol engine oil..... race motors in the 50's ran with that all the time.

 

[Tailgate]

Well, I was kinda kidding but, always nice to know....

 

[RJ2112]

Think of it as biodiesel, before it became sexy to have a name for it.

As Kerosene is also Diesel fuel, which is also extremely close to aviation JP4 or 5.... and it's all light grade oil probably in the 1-5 wt range..... why don't diesel vehicles use the fuel for lubrication, before they burn it? You'd always replenish the engine 'oil' whenever you re-fueled, it wouldn't get fouled with emissions by products, you wouldn't have anything to recycle. Spin on a new filter at teh recommended intervals, and there you have it.

 

[chihuahuastud]

What about changing brands but using the same weight? Got half a bottle of Motul sitting there that I don't want to waste.

 

[RJ2112]

What about changing brands but using the same weight? Got half a bottle of Motul sitting there that I don't want to waste.

Look at your manual..... as long as you are in the SAE and API recommendations, you have nothing to worry about. If the manual, or the labels on any of the bottles of oil were to say anything in print that this is a bad idea, I would honor their written specification.

The whole point of having a standard is to make sure everything 'plays nice' together, no matter what the source. If all your oils are API SE,SF,SG type or higher and within the 10w-30 to 20w-40 range.... you should have absolutely no issues mixing brands.

 

[macem29]

Think of it as biodiesel, before it became sexy to have a name for it.

As Kerosene is also Diesel fuel, which is also extremely close to aviation JP4 or 5.... and it's all light grade oil probably in the 1-5 wt range..... why don't diesel vehicles use the fuel for lubrication, before they burn it? You'd always replenish the engine 'oil' whenever you re-fueled, it wouldn't get fouled with emissions by products, you wouldn't have anything to recycle. Spin on a new filter at teh recommended intervals, and there you have it.

rhetorical question I'm guessing? lack of lubricating properties, gets worse
as diesel evolves, ie: low sulfur diesel and engine problems....I've seen many
diesel engines die because of a leaky injector or internal fuel leak, bottom end
done in a hurry, but I like the thinking :thumbup:

 

[RJ2112]

rhetorical question I'm guessing? lack of lubricating properties, gets worse
as diesel evolves, ie: low sulfur diesel and engine problems....I've seen many
diesel engines die because of a leaky injector or internal fuel leak, bottom end
done in a hurry, but I like the thinking :thumbup:

Yes, it's rhetorical.... a mental excercise to keep the neurons firing. I don't think it could be retroactive to an engine designed with a 'typical' lube system.

All rocket engines use the fuel to cool the engine nozzle before feeding it into the combustion chamber... it's used to 'preheat' the liquid Oxygen and Hydrogen, as well as ensuring the structure of the nozzle doesn't weaken due to the exhaust.

Pretty sure the relatively 'cool' fuel would have similar viscosity as heated engine oil, so it would be a matter of supplying that same temp fuel to all points that need lube; and probably at a higher pressure than what is used with thicker oil.

The other concern would be whatever by products were blown into the fuel on it's one pass through the cooling cycle clogging the injectors.