mixing brands- weights

[clarkflower]

I have a question.
I saw someone said not to mix oil with a 15 40 or 15-50 weight cause of a low vi (something like that)

I would like opinions, can I mix 1/2 German Castrol 0-30(as they said it was thicker)with Mobil 1 HM 10-30 to still be using the called for 30 (opposed to moving up to a 40 wt)

Thinking I am getting the add pack of the Mobil 1 High Milage + the thicker 30 wt of the German Castrol.
Is this thinking OK or do those two not mix/ work well

 

[chubbs1]

If you had them in your stash and you needed to use them up go for it. If you are going to buy two separate oils to mix I would say don't do it. The M1 HM is plenty good for that engine. It is an excellent oil. All API SL,SM,SN oils are miscible but the additive packs can be affected or "clash". It is best to stick to one or the other.

Let me just add, your engine will not blow up from mixing the two. I just would not go out of my way to do it.

What vehicle do you have? Can you use 5w30 HM? That has a better base-stock than the 10w30.

 

[Artem]

I think you'd be closing in on it being a 40 grade but it shouldn't hurt a thing and will probably shear right back down into the 30s in no time.

Just like Chubbs said, if you gotta use up some spare bottles, go for it!

 

[clarkflower]

>>What vehicle do you have?

A 700 dollar 97 Kia Sephia with 97k that I want to drive till it dies. It burns quite a bit of oil

 

[CATERHAM]

Originally Posted By: chubbs1
All API SL,SM,SN oils are miscible but the additive packs can be affected or "clash".

It would be more accurate to say the additives in different API oils may compete with each other but they will not "clash".

clarkflower, it was probabily myself who advised against using low VI oils such as the 15w40 and 20W-50 grades as blending candidates. The reason is these are antiquated dino grades and there are much better oils to use if you're trying to increase the viscosity of some 20wt or 30wt oils.

Regarding mixing GC and M1 10w30. These oils are similar in that they have the same HTHSV of 3.5cP but the 10w30 is a low VI (149) oil so it is heavier than GC on start-up at all temp's.
(I don't recommend a 10w30 syn' for any application).

I don't know what you're trying to acheive here. The only reason to consider a HM oil is for it's seal swell properties and the 5w30 would be a better candidate in that regard.
As others have asked, we really do need to know your application to give the best advice.

 

[clarkflower]

Originally Posted By: CATERHAM
Originally Posted By: chubbs1
All API SL,SM,SN oils are miscible but the additive packs can be affected or "clash".

It would be more accurate to say the additives in different API oils may compete with each other but they will not "clash".

clarkflower, it was probabily myself who advised against using low VI oils such as the 15w40 and 20W-50 grades as blending candidates. I don't know what you're trying to acheive here. The only reason to consider a HM oil is for it's seal swell properties and the 5w30 would be a better candidate in that regard.
As others have asked, we really do need to know your application to give the best advice.

Yes it was you..
Thanks so much.
As I said I have a $700 97 Kia Sephia 1.8 with 96,000 that I drive maybe 50 slow in town local miles a week in So Ca.I changed to mobil 1 10-30 and for 1 month my oil was perfect,never lost a drop.Runs great no smoke that I see.Cold air but looks like it was painted with Ben Moore house paint right over the old decals LOL
While house sitting 25 miles round trip highway miles away from work I went through 4 qts in 30 days!
I just had a car lose an engine and don't have much money. I don't think it's worth doing rings or values on a 700 dollar car but it would really help me to get a few years from this so I want the best oil I can get to help.I was thinking I could get a thicker oil, still swell the seals with those two oils 0-30 GC and the HM mobil 1 10-30 hm without going to an uncalled for 40 weight.
Thanks

 

[CATERHAM]

Okay, since money is tight and we don't know the exact reason for the high oil consumption (likely the oil control rings and/or the guides) I wouldn't use any expensive synthetic oil.

I'd use any 5w30 or 10w30 dino oil you can get cheap on sale.
Unless the oil consumption produces oil smoke in the exhaust I wouldn't worry about it too much.

 

[KCJeep]

I'm an incurable blender, but I've learned to modify my behavior a good bit from what I've learned on BITOG. I no longer mix brands, and also try to stick to high VI, but for your application I doubt it would make a bit of difference, just get rid of what you have.

 

[fdcg27]

In most of California, the climate is quite moderate.
You could use a 15w40 year round with no problems.
While these may be low VI oils, I don't think it'll matter.
Your first priority is keeping oil in the engine.
Look at it this way, for several months each year, the 5W-xx or 0W-XX oils I use for winter in our cars are actually thicker at start up than 15w40 would be in your climate, since viscosity is entirely a function of temperature.
You note that you are currently short on funds, so I would not recommend blending two pricey oils for an engine that will quickly burn through them, and which requires nothing special in an oil to begin with.
I'd go with any 15w40 that carries both API "S" and "C" approvals, and you'll be doing fine for your engine.
Avoid oils not dual rated, as these are intended for diesels only, and may harm your engine.
If you can find Kia's orginal oil recs somewhere, 15w40 probably falls within their recs for the car when it was new.

 

[clarkflower]

Originally Posted By: fdcg27
I would not recommend blending two pricey oils If you can find Kia's orginal oil recs somewhere, 15w40 probably falls within their recs for the car when it was new.

I could not find the kia chart...just 10-30

I notice both you and CATERHAM made ref to the money. I forgot to put that in 60 days of my normal driving with that combo of oil I was down 1 qt so I am not opposed to spending 6 bucks every 2 months if it may help me have a longer life of the car.

 

[Ken2]

When mixing multiweight oils of different viscosity grades, you do not get the arithmetic average of the mixture. The only way to know what you end up with is to get it tested.

Mixing oils won't hurt except perhaps you won't get the benefit built into just one of the oils. Two different brands or oil lines from the same brand aren't twice as good as just one of those, and the mixture may not be quite as good as either.

 

[fdcg27]

I made this point in another thread, and was "corrected" by another member.
I think that most oils are formulated properly with the additive pack the blender used.
I don't think that mixing oils using different add packs can yield a better result.
If that were the case, all of the premium oils would have just a little bit of everything in their add packs, and that isn't the what we see.
In the case of the OP, we find someone who lives in an area with a moderate climate trying to maximize the life of an engine with undemanding requirements that goes through a fair amount of oil.
I would thus recommend the cheap and readily available 15w40.
No sense in pouring a more expensive oil down this rathole, or in pouring more of a thinner oil into it.

 

[Garak]

Originally Posted By: clarkflower
I notice both you and CATERHAM made ref to the money. I forgot to put that in 60 days of my normal driving with that combo of oil I was down 1 qt so I am not opposed to spending 6 bucks every 2 months if it may help me have a longer life of the car.


I'd agree with most of what CATERHAM suggests, but have a couple extra suggestions. As he suggested, use a competitively priced dino (in an appropriate grade, be it 5w30 or 10w30) and top up as needed. Alternatively, try a high mileage oil, if you can get one at a sensible price. With a leaking engine, I had good like with Valvoline MaxLife synthetic blend 5w30.

CATERHAM won't like this, but I'd have no objection to you using a 15w40. It may help slow down leaking and can probably be had at a reasonable price. It can also be bought in a five gallon pail, which means you'll have plenty for oil changes and top ups. Yes, it's heavier than necessary, but if it slows your leaks and saves you some grief and dollars, that's fine. Your climate is warm enough, and it's not like the car is under warranty.

It's far from an optimal choice, but it may be appropriate for your circumstances. Any of these options, however, can be cost effective.

 

[clarkflower]

Thanks all!

The only time I have seen smoke was a puff of blue while shifting (one of the few times I took it to 3500)

I would like to confirm the the advice not to use SYN is all money and not cause that its bad to use with leaking rings.

Thanks Again

 

[fdcg27]

In my case, I recommended what I did for economic reasons.
Synthetic by itself should not cause leaks where they don't exist, and shouldn't by itself make leaks any worse.
A thicker oil may help with the leaks and consumption, and there is no sense in paying synthetic prices for oil used in a car that will both leak and burn it at a significant rate.
Remember also that the engine of your car is not hard on oil, and every top-off replaces additives in the oil in the sump.
I usually use synthetics, but if I had your car in my fleet, it would get 10W-40 winter and 15w40 spring, summer and fall.
This thing will not benefit from the use of a thinner oil.
It will only leak and burn more.
The engine can live for a very long time with its current rate of oil loss, though, as long as you keep the oil above the add line on the dipstick.
You might find lower consumption if you maintain the oil level around the add oil line, rather than at the full line.
I know that some engines have a lower rate of consumption when not kept completely full.

 

[Garak]

Originally Posted By: clarkflower
I would like to confirm the the advice not to use SYN is all money and not cause that its bad to use with leaking rings.


I'm not one of those who believe that using a synthetic will "cause" leaks or oil burning. However, I certainly don't believe in using synthetic in a leaker or burner (unless it's required by specification). After all, if it's consuming $3/quart oil, why have it consume oil that costs $7 per quart or more?

 

[virginoil]

What grade is there that you need to blend which you cannot buy off the shell ?

Using surplus oil for top up purposes when required is a different matter.

Mixing oils of the different brands has never been promoted on BITOG as long as I recall.

Mixing grades within the same brand ie Mobil SM with other Mobil SM grades, no problem.

 

[Jim Allen]

Me, I'd recommend a HDEO (dual rated CJ-4/SM for mixed fleet gas & diesel). I think an HDEO would be better suited than a PCMO because they have a much more robust additive package, i.e. better dispersants & high anti oxidant capabilities and possibly (I haven't verified this but I've been "told") about the equivalent amount of seal swell additives as a PCMO HM oil (High Mileage). I diverge from my esteemed colleagues above by recommending a 10W30 grade rather than a 15W40. I'm not convinced that a 40 grade is always warranted or effective in oil burning situations and it near isn't optimal for short hops. Still, 10W30 HDEO seems to be scarce in some areas (try WalMart & Farm stores but some auto parts placed carry it... make sure it reads CJ-4/SM on the roundel) so the 15W40 would be my second choice.

 

[Garak]

Another good suggestion, Jim. My suggestion that 15w40 is available in large pails (for convenience for a burner/leaker) certainly would work just as well with a 10w30 HDEO. I don't know about down south, but with respect to PCMOs, Walmart has their Supertech in 5 gallon pails up here, and at a price that's hard to beat.

 

[fdcg27]

There are more HDEOs available in 15w40 than in 10w30, at least in the US.
I don't think that a 15w40 would cause any harm in the OP's climate.
Therefore, I would recommend a 15w40 HDEO, simply because you can find it more cheaply than the less common 10w30.
If the OP can get a deal on a 10w30 HDEO, great.
If not, I'd use a 15w40 in the beast myself.
Cost is a real concern with an engine that's burning and leaking plenty of oil.
Leaks and consumption would also likely be lower with this sieve using a thicker oil, and I doubt that it would hurt this engine in the climate in question.