Is a straight-up double better than a cocktail blend for engines?

[ZiTS]

Hello everyone. Like many others, I found this site a few months back and feel like I finally have a place to go to get my fix! It's really nice to know that there are others out there like me (mad scientist laugh in the background...)

Anyway, my question is as follows: I've been doing a lot of research on motor oils and filters, and one thing that I am seriously wondering about now is whether or not it is better to use the same brand oil all the time, or if it is better to switch brands at every oil change. The reason I ask is that out of all the topics, discussions, forums, and research, it seems that there really isn't a "bad oil" to use anymore, but that each brand seems to have different strengths and/or weaknesses.

For my example/question, let's assume the viscosity stays the same (5w-30,10w-30,...), and that either a synthetic is always used, or a dino is always used. Also, oil changes are done every 3,000 miles. HYPOTHETICALLY, let's say Brand X has great anti-wear, but not great anti-foam. Brand Y has great anti-foaming, but not so great of a pour point. Brand Z has a great pour point, but not a great detergency package, etc. Getting the idea? Now let's assume that Brank K is used solely, but it has a low TBN. To me, it seems that by constantly switching brands between Brand X,Y and Z, you'd be getting the best overall packages over the live of the engine, whereas by using only Brand K, its' weakness will not be masked.

It's just that I've heard time and time again stories of people who use "whatever oil is on sale" taking apart their engine and finding it to be as clean as the day it was built. I've also heard people who always use only one brand say that they've found either sludge build-up, varnish, etc. on the inside of their engines when taken apart. I'm not sure I really buy the 'seal swell' argument, so are there any other opinions/comments?

Thanks for taking the time to read this whole thing. I know this is a lengthy first question, but any thoughts would be greatly appreciated.

 

[GROUCHO MARX]

I don't think that 3k changes, mix of city and highway driving, that you would see a noticeable difference with any SL rated oil.

jmo

 

[ZiTS]

Maybe I phrased the question the wrong way. I'm not talking about being able to notice any difference from oil change to oil change. I'm talking about the big picture, over the life of the engine. Whether you choose 3k mile oil changes with dino, or 10k mile oil changes with synthetic, what I'm interested in is whether or not it is beneficial to switch brands, or stick with only one. I guess it's similar to the thinking of always using different brands of gasoline (I've always believed it's better to switch gas stations every-so-often). Obviously no oil company is going to tell anyone to always switch brands, but I'm looking at it from the consumers viewpoint. Isn't it better to benefit from the chemical knowledge of various oil companies, or just go by what one of them says?

[ November 08, 2003, 08:12 PM: Message edited by: ZiTS ]

 

[GROUCHO MARX]

Over the life of the engine I doubt there would be any difference. The posters here would say find a good oil and stick with it. Some would talk about additive clash. Others would say it's a myth.

Choose your path, grasshopper.

 

[JohnBrowning]

I think I follow you. I think you are waqnting to prevent build up of simalr additive package by switching brands. I do not know if this would work. The only place I have heard this theory is with hair shampoo's. Supposedly you should switch every 28 day for a week or too to reduce build up from product on your hair.

I think sludge is more common today for a number of reasons inspite of the wounderful oils we have. People simply abuse their cars buy not following realistic OCI. To add to this people will start up their car to drive three houses down or to check their mailbox.IF their have to go 1/4 mile down the road to talk to someone they wont walk to save their life! 3000 miles 1-2 miles at a time is hard on an engine and it's oil.

 

[eljefino]

quote:

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It's just that I've heard time and time again stories of people who use "whatever oil is on sale"

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I subscribe to this theory. For one thing, it encourages sales. I do it with Coke/Pepsi too.

I use the sale oil during the more temperate time of the year-- least challenging on it if it's mediocre.