Seems allot of folks on here would like to bash 15W-50 oil...or are rather missinformed about the oil. So let me break the myths down 4 you.


1. 15W 50 isn't good for the LT-1 5-W 30 is what the engine calls for.

*Bull..doo doo!* 15W-50 is good for any High Performance engine. THat's just what the stuff was designed for. It's a thicker oil to provide high stress engines with more protection...sure 5W-30 or whatever is find when you step put the factory with your stocker...but when you start ripping stuff apart and adding on items and boosting those HP and Stress ratings up...it be good to have a little more protection on your engine as a safety to fall back on. Not saying you still couldn't use 5W-30...but 15W-50 will offer you a bit more protection.


2. It's not good in cold weather.

My 15W-50 is more hard core than my fuel in the cold. Cranks right up. Feels just as good as it does in the dead of summer.

3. It will cause overheating

Overheating issues with 15W-50 nothing to worry about. Been using 15W-50 for over a year now. Never had an oil related over heating issue. Avereage temp on a 90degree day is 185 exactly.
Same temp all year round under a normal bases.


4. The truth

15W-50 is just as good as anyother oil out there. THink of itas a raw form of protection. It does the same thing for you Lucas...and prolong do without dishing out htat extra 20.00 Ever since I got 15W-50 I stopped throwing in the extra crap...and the car runs just as smoothly and the oil stays clean for a very long time. I change my oil between 3500-5000 miles and e ven then the oil is still usable.

So what is the point of this? Don't be affraid to use 15W-50 theres nothing wrong with it!

 

using the thicker oil, will it permaturly wear out the oil pump?

why don't the auto makers make not of this oil to be used in our lt1?

just curious? is this ok to use in the winter months?
zoso

 

Perhaps the "truth" in your opinion. You have no hard data to backup any claim. Your arguements have so many holes in them, that even 15w-30 oil would pour through. Just because your car starts in cold weather, the oil is good?

 

5W-30 is better in any way compared to 15W-50 UNLESS your engine leaks (from rear main, intake, etc.) or consumes oil. 5W-30 has better viscosity, so it will lubricate the internal engine parts better (especially when the engine is cold) therefore give you better protection.

 

Not that I diagree with you, but your arguments are highly subjective. Don't bash the people that question using a (15w-50) oil not recommended by the manufacturers unless you have facts and not just opinions to back you up.

I use Mobil1 15w-50 in the summers but not in the winter here.

 

15 for a winter weight is kind of high.

The reason the synthetic 15W50 stays clean longer is because it has less detergents than an oil like dino Quaker State which is loaded with detergents.

I use Quaker State *BECAUSE* the oil comes out dirty.

If an oil comes out dirty it means its cleaning your internals.

That being said, 15W50 synthetic is fine for race motors. Especially if you have a bit more clearance in your bearings.

 

When I was in college I had several classes and discussions on engine oil, whats good, whats bad for what kind of engine, milage, temp etc. Now I work at a Benz dealer and Mercedes has had endless problems with engine oils and oil consumption. They'll now replace and engine for free up to 150000 miles if you burn more than 0.8QT every 1000 miles (class action law suit). They've had us switch oil viscosities several times because (according to them) USA oil grades are lower than the European grades. They've now settled on Mobil1 0w40 all year round.

I could go into a lengthy discussion on engine oils but everyone on here has their own opinion about whats best. Really, for us it doesn't make that much of a difference because we all beat on our cars. Our engines don't fail becasue we used the wrong grade of synthetic oil. I use whatever half empty bottles of Mobil1 are lying around the shop, 10w30, 0w40, 15w50, 5w50. I have a Mobil1 cocktail

 

I'll wait for Patman to answer this one.

 

Exactly! He has no hard data to back up his claims.

Heatmaker, do me a favor and get your oil analyzed at the end of the next interval. If you can beat the numbers I got on my last oil analysis running German made 0w30 Syntec, I'll be extremely surprised. Here are the numbers you'll be gunning for:

Iron-4.8 ppm
Lead-3.1
Chromium-0.2
Copper-1.8
Aluminum-0.8
Nickel-0
Titanium-0
Silver-0.7

I ran this oil for 3100 miles, drove it very hard a lot, including 9 quarter mile runs.

Do me another favor Heatmaker, and pop on over to this site and do some reading:

http://theoildrop.server101.com/ubb/ultimatebb.php

I'm an administrator on that board, and the people on there don't usually make claims like you're making unless they've got good hard facts to back themselves up.

I've been playing around with different oils in my LT1, and paying attention to what other people have been running, and so far nobody has come close to running as good of an oil analysis as mine yet. Are you up for the challenge?

 

Just curious... have you ever had your "used" engine oil tested for contaminants, metals, etc? Unless you have, you have no basis for most of your statements. No way to judge used oil by its appearance or by its "feel" when you start the engine.

A "15W" cold viscosity oil (the "15W" in 15W-50) simply does not flow as well at 0degF as a 10W, 5W or 0W oil. Not subject to discussion... it is the technical basis for labeling the oil. Most engine wear occurs on cold start. It you are living in a cold climate, you need something that flows better than 15W to protect the engine on startup... or maybe you have an "pre-oiler" system, and this is irrelevant. A simple oil analysis, comparing the levels of bearing materials present in your used oil, using both the recommended 5W-30, or your preferred 15W-50 would prove (or disprove) your postion.

Why were you throwing "extra crap" like Lucas and Prolong in your 10W-30? It isn't needed and is a huge waste of money on ineffective products.

We've read your statement, now let's see the data to back it up.

 

My dad belives in the "thicker is better" analogy also. But the problem is that back in the day when guys built fast engines they used loose tolerances in order to make good power. Today's engines use much tighter tolerances and therefore do not need a thicker oil. In some cases it is worse to run thicker oil than a thinner oil in newer cars.
FWIW I use Mobile 1 5w-30 in the winter and Mobile 1 10w-30 in the summer.

 

you got a degree in chemical engineering?

i'm pretty sure racing motors do not use 50W, in fact i think they use like 20W or something. Patman, what kinda air filter are you running? low wear #s.
looks like all your research has paid off.

 

I was using a Fram air filter on my last interval, but have since switched back to a stock AC Delco. I do believe both are pretty close in filtering ability though.

As far as racing engines, it all depends on what type of racing, but I do know that a good majority of NASCAR engines are running on Mobil 1's 0w30 racing oil. This oil just recently went on sale to the public actually.

 

Thats right. Cold starting an engine can cause about the same wear as driving the car for 700 miles, according to some book I read once. Its kinda silly if you think about it coz that means I should change my oil every 5 starts

 

Many NASCAR teams run 5W-30 or even 5W-20 (the new viscosity established under ILSAC for many new engines) in their engines turning 8000 RPM and making hundreds more horsepower than we can dream of in our LT-1s. Their reasons are less parasitic drag, better flow, more horsepower. And all of it based on the science of hydrodynamics, which accurately describes the process of lubrication in a bearing, which is far more complex than "pressure" or "thickness" arguments, which are far too simplistic.
So much for the thicker is better argument. If you had a clapped out British sportscar from the 60's, thicker is better. Not today.
I love anecdotal information presented as fact. It is so easy to disprove, and the logic so childlike.....