Our point is, what proof do you have that the 15w50 offers more protection because of it's thickness? If an oil is too thick for the clearances in an engine, you'll just run hotter oil temps and your oil flow will not be good enough to provide the right lubrication. Not to mention the fact that when you first start up the engine cold, even in the summer, that oil is so incredibly thick that your engine is not getting enough oil flow.

Like I said, do yourself an oil analysis and prove me wrong. If you're so sure this oil is the best, then you should have no problem whatsoever spending $20 for an oil analysis.

 

Right or wrong, I also use the red top 15W50 Mobil 1 oil. I do so because my engine building/mechanic buds with about 100 years combined experience recommend I do so. No reason other than that

One of these guys does run the same oil and has had his oil tested. I've asked him before for the results so I could post them but never go them... kinda dropped the ball. I'll get on him this weekend to see if he can find the paperwork and if he can, I'll post the results!

 

Please note that Brent lives in the southern part of Florida and is also referring to the use of synthetic oil. IMO, synthetic has greater flow characteristics than dino oil.

 

Yes, this is an important point and additonally the synth provides better protection to boot. There are so many variables to seriously consider (climate conditions, how the engine is built, yet alone it's design, how it is used, etc) that it is difficult to arrive at any one "best" weight or type oil universally.

 

This is very true. This is also why oil analysis can help you out so much, because it can then help you determine which oil and which viscosity will work best for your particular situation. I find it a bit strange that so many people are interested in finding out what oil they should run, but yet won't spend the $20 to get an oil analysis done. There are many good labs out there that can do this for you.

 

What kind of oil NASCAR drivers use is not relavent in our case. Reason being they want their cars to produce the max hp for a few hours.

After the race alot of those engines are torn down and rebuilt with new rings and bearings for the next big race.

They aren't looking for longevity. Just looking for max hp.

 

A 5w30 will creat a thinker film btwn the bearings than the 15w50 will. Oil pressure isn't everthing its just having to work harder. True you want good oil presure but not threw the roof. their is a reason the factory said 5w30 , big deal if your motor was hopped up, bearing clearances are bearing clearances. I attended a stupid class for work, the pennzoil rep. was there and he spoke about how old farts like the 10w40 and 20w50 oil, its crap oil, but the market wanted it so they made it. He talked about how they test motors for 200hrs at 3000rpm agianst other oils. he said a thinner oil will disapate heat better than a thicker oil will too. Pennsoil is in the making of a high mileage 10w40 only because the stupid people think a thicker oil is better, i wouldn't run high mileage in my car, but look for it in a couple weeks, and its only purpose is to sell, a market wants it so they make it.

 

choosing an oil is not about what oil you "like"............no one cares what oil you "like".

people care what oil will be best for their engine.

determining this requires testing.

your ancedotal stories "my car starts in the cold, doesnt overheat, and the bottle says high performance so it must be ok for my car" do not prove anything.

run the 15w30 in your car for 3000miles, then get an used oil analysis by a laboratory to show that there is actually a reason that you "like" this oil over the other choices out there.

otherwise you might as well "like" that oil just because it comes in a pretty container.

 

Excellent point, shoebox. I should have pointed out I do live in FL and where I live it freezes maybe just a few times a year. In fact, right now it is over 60 degrees here

 

Did I say that he did? No. He said some Nascar teams are now using 5w-20 and I said I don't know how many people would want to use that in their expensive bottomends. Make sure you read correctly what I'am posting.

 

Could that reason the factory wants you to run 5w-30 is for the engine to run more efficent (sp?) so it will burn less gas because of the lighter oil?

I suppose if that pennzoil rep told you to jump off a bridge you would do it too. Stupid people think thicker oil is better? Man, you better get some facts to back that one up or some people might get angry.

 

I guess I'm still not understanding you. Why did you take his statement of fact about NASCAR and start comparing it to peoples expensive bottom ends? I don't know, why WOULD you want to use 5w-20, just because NASCAR does? I would only use it if that is what the manufacturer or builder recommended based on the tolerances.

In reality you could walk into any auto parts store and purchase any motor oil off the shelf and as long as you change your oil in reasonable time intervals you engine can live a long healthy life.

The design of bearings isn't an exact science. The engineers are designing bearings and specifying 1 viscosity for a number of different bearings in the motor plus the valve train.

Even if you do understand eccentricity ratio, viscosity, Sheffield(sp) Number, and the works of Raimondi and Boyd or some other accepted solution, you would still want to select the viscosity for your oil based on empirical wear results like Patman is doing.

just MHO,
brent

 

Thats what Im running this interval(Mobil 1 0w40)....I plan on sending a sample out to Blackstone Lab when I drain it .

 

Most intelligent words in this thread. So your oil is clean.............where does all that carbon go then?? hmmmmm

 

No No No. You don't understand at all. He said that some Nascar teams are using 5w-20, and from my little experience I haven't heard of anyone using this oil in there streetcars so I couldn't see why people would want to use it in their cars (just my opinion). I don't care what they would want to use its just my personal opinion. Get it now? I never said once that I wanted to use it because nascar does, read my post AGAIN! I never said I even wanted to use it to begin with! I'm going to have to draw a picture here or something. I don't know how I could be more clear.