I have been running Delo 400 xsp 5w-40 for a while and can't seem to locate any at this time. I have 6 quarts and wondering if it would hurt to mix 4 quarts of 15-40 xsp with the 5w-40. I'm in Montana ! Thanks
Mixing Viscosity's
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What kind of low temps do you see in the winter?
Both are 40-grades so you’ll get a 40-grade. It’s the winter rating that’s not guaranteed.
Mixing oils is one of the top topics on Bitog.
Mixing oils is one of the top topics on Bitog.
It depends on whether the cold temp properties are important to you. When you start mixing multi-grade oils, it is difficult to predict the outcome of the "W" rating.
Nothing wrong with mixing, but as critic pointed out, tough to gauge what the winter rating will be. Looking at pure average of numbers, your proposed mix would be around an 11w40. Based on each oil's specific property, that may not be the true number but it'll be a ballpark.
I would not like to have a 10w+ in the sump for Montana winters, but unless you consistently see -20* temps, it will technically be up for the job.
I would not like to have a 10w+ in the sump for Montana winters, but unless you consistently see -20* temps, it will technically be up for the job.
What are the viscosity limits for an oil with an 11W winter rating?
Non-existent. But for a 10w I believe it's -22*.
-17 the last two winters !
Yes, the 5w/15W 40 mix is fine for the summer, but you don[t know what cold pumpability you'll get once the temperature drops below freezing. Since you are mixing the same formulation of oil, you shouldn't have a problem with additive clash. But for cold pumpability, I would assume that it's going to perform like a 15w40. 15W oils are good for starting down to 10F. If your truck is parked inside or on a block heater in the winter, that would be OK. But for unassisted cold starts at -17F, I would have 5w or 0w40 in it.
Is that a new Polaris viscosity rating? They did have 2W50.
At operating temperature there won't be any change. But the viscosity will be thicker until reaching operating temp.
Mixing viscosities | Widman International SRL
Research the product specifications and do the math using the below:
www.widman.biz
Mixing viscosities | Widman International SRL
Thanks for all the replies !
I don't know if what I'm thinking is a valid point but, 5W40 and 15W40 have different density at the same temperature. The oil with lower density, 5W40, will end up floating above the higher density 15W40 in the sump. You'll end up with 15W40 being pumped first since it is at the bottom. Simple physics I imagine. I could be wrong though if mixing two different densities would result in an average of both.
What?? No, they are miscible. This is wild imagination.
Sometimes I'm too carried away
The oil will mix.