oil experiment

[dethinboots]

mixed 6qts of Mobil 1 5w30 to .5 of 15w50. its starting to cool off a little, but its still Texas. thoughts?

[cammed goat]

I don't think it would do any harm to the engine.

[Smittro]

Why are you trying this mixture?? Curious.

[dethinboots]

hot weather, spirited driving, and mild travel

[Too Fast]

So you are now running ~6w33. I don't see the point...run what the engine builder says.

[Smittro]

I agree with too fast..

[dethinboots]

6w33? who what? I mean I've read some bobtheoilguy threads, but am not versed in these matters. explain please w/ pros and cons. come on guys I asked to learn.

[2002ssslp]

I use 5W 30 Mobil 1 with a bottle of Lucas synthetic formula. It works for me.

[Smittro]

Well, with modern engines came tighter tollerances so heavy oils can sometimes cause issues.

Example.. My LQ1 engines stock required 5w30 anything heavier and the engine would make noise over 5500 rpm.

@ 7000 rpm the noise was a little scarey.

But it also came from the factory with a high volume oil pump so that may have had something to do with the noise I got trying 20w50.

You're not the only one that runs a soup. I ran a soup of 10w30 and 20w50 in my l36 camaro and saw a slight improvement in mpg's.

That engine called for 10w30.. I later changed to strait 5w30 and saw even more gains in engine smoothness.

Some even go as low as 0w30. From what I've learned here from Sarge (when the old man was a regular) was that most motor oil weights reduced by half with operating temp and or heat soak.

Example, 5w30 becomes 0w30, 10w30 becomes 5w30, and so on..

Alot also depends on the add packs with various brands, in friction modifiers and so on.

The best way to see if your "soup" is having any benefit is to have a UOA done to your soup with the next oil change.

[Smittro]

Cont..

The higher the particulates @ a given ratio the more likely the soup is'nt having a good effect on your engines internals.

The lower the better. As motor oil particulates are a measure of engine wear.

This is why I also try to steer people away from using K&N air cleaners, and cheap oil filters.

[Smittro]

Now the reason I agree with Too Fast, is simple, few people do a UOA or even know what the hell it is.

In which case I would say run what the manufacture calls for as they have already done their motor oil home work on your engine durring it's engineering.

[dethinboots]

thanks for the input. ive been wanting to do an analysis on my oil for quite awhile so i figure next change would be as good as any.

[Smittro]

thanks for the input. ive been wanting to do an analysis on my oil for quite awhile so i figure next change would be as good as any.

Give it a shot, maybe have a couple test done so to possibly build a picture of what is best for your engines needs and how you like to run it.

Worse case I've heard was about it being possible to spin a bearing running too "heavy" of an oil.

That would'nt be much fun, lol. But personally I have never seen an engine actually do that.

[Too Fast]

What Smittro said, nicely done.

6w33, I didn't do the math, but the .5 quart addition of 15w50 into the 5w30 just thickens the whole soup a bit.

If you run thicker then necessary oil, this just adds to the parasitic drag in the engine, reducing HP and fuel mileage a bit. Not a whole lot, but everything helps, right? Normal operational temps call for normal engine oil.
If you start autocrossing or hop lapping, and I mean again and again and again for an hour or so, than yeah you could make the case for a 15w40 or something heavier for extreme duty like that. For the occasionaly drag strip duty, or the fun driving on curving roads, use what the engine manufacture recommends.

[dethinboots]

thanks for the input guys. i def wont make anything to thick for the mileage and potential harm. after the analysis ill determine where i go from there.

[cammed goat]

Keep us updated.

[dethinboots]

on a positive note... Ive run this oil for over 2k now and its still clear and pretty.

[Too Fast]

This usually means your engine is in pretty good shape, but the best way to tell is with an oil analysis.

[04yellowjacket]

i have been running royal purpal 20/50 race oil in my modded ls1 all summer. now it is starting to get colder here in oklahoma i will be going back to 10/30 royal purple. it is costly oil but it is very good oil.