# What do you think of this mix??

#### j454

I was changing my trans filter and thought now would be as good as time as any to change the oil. I have a very limited stash and my Yukon Denali with 6.0 engine holds a tad over 6 quarts. I had one 5 qt jug of M1HM 10W-30 and a couple 1 qt bottles of M1TDT 5W-40. So I thought why not mix these two? So I used the 5 qt jug of the 10W-30 and 1+ quarts of the 5W-40. So my question is; what would these two be if mixed 50/50?? I've read that there is a formula to figure out the end result of two different weight oils mixed, can anyone tell me this formula or post a link? Thanks in advance

#### j454

Thanks for the link. As of now, I don't know how to use it, but will figure it out in time.

#### ekpolk

While you're figuring it out, and since you asked, just be aware that it's not a process of simple weighted averages. In other words, you can just add them up and divide. It's a logarithmic calculation, as I understand. Also remember that the SAE "grades" are actually ranges of viscosity. So you can't take two quarts of 30, and two of 40, and conclude you have an SAE 35 wt oil. First off, there is no such thing. Second, you really need to look at the specific vis for the fluids in question (how many cSt). And finally, you have to make the correct calculation.

#### demarpaint

Use the top calculator. Take the oil you plan on using, plug in the 100cSt #'s found on the spec sheets for the oil in the KV1 box. Then take the second oil plug in the specs in KV2 box. Now take the % of oil in KV1 box that you'd like to use, lets say 50%. Plug in 50%. Leave temp set at 100C because that is the operating temp you car will be running at when fully operational +/- a little. Hit calculate, and you have your answer. Now at the Bitog homepage they have a viscosity table, and that will tell you if you have a 20 grade 30 grade 40 grade etc. Go easy on my explaination, I'm sure there are others who can explain it better.

#### j454

Originally Posted By: demarpaint
Use the top calculator. Take the oil you plan on using, plug in the 100cSt #'s found on the spec sheets for the oil in the KV1 box. Then take the second oil plug in the specs in KV2 box. Now take the % of oil in KV1 box that you'd like to use, lets say 50%. Plug in 50%. Leave temp set at 100C because that is the operating temp you car will be running at when fully operational +/- a little. Hit calculate, and you have your answer. Now at the Bitog homepage they have a viscosity table, and that will tell you if you have a 20 grade 30 grade 40 grade etc. Go easy on my explaination, I'm sure there are others who can explain it better.
Thanks for your crash course. I've been busy with other things and just now got back to check this out.

#### j454

ekpolk; Thanks, I did read what you stated and heard about the formula for figuring this. So thanks guys for your time.

#### BrianWC

As for the oils themselves, I would think they'd be fairly similar and mixable. Any other opinion on that?

#### hate2work

Originally Posted By: BrianWC
As for the oils themselves, I would think they'd be fairly similar and mixable. Any other opinion on that?
I think you're right. When I asked about mixing oils to make a blend, I had a few people warn me about the add packs clashing. But I also had several more tell me they had mixed all kinds of different oils for years with no apparent downside. The bottom line seemed to be that if you were going to mix oils it would be best to stay with one brand if possible.

#### mechtech2

It's not a 'clashing' or incompatibility that I would be concerned about, but simply a possible less effectiveness because of 2 add packs that don't reinforce each other, and never live up to each one's original potential. Since most common oils use the same stuff, it generally is not an issue.

#### j454

I thought I'd like to run the M1HM 5W-30 but so far can't find it. My engine reccomends 5W-30 in the first place "GMC 6.0L". I also thought about the M1TDT 5W-40 but am just a little concerned about the 40 in the 5W-40. I'm thinking that the M1HM 10W-30 with a touch of M1TDT 5W-40 may just be about what I want anyway. I assume that M1HM 10W-30 should do as well or better than a dino 5W-30? Antway, if there is any good known reason not to mix these two please let me know.

#### chevrofreak

I'm blending M1 10W-30HM and M1 0W-30 AFE 50:50 for my next oil change. I'd have bought the 5W-30HM, but it wasn't available. Plus, there is a \$10 rebate on the AFE right now.