I've looked through numerous threads and have seen contradicting opinions. The car has a small oil leak coming from the front of the engine some where. I'm not currently sure what oil is in it as I wasn't the last one to change it nor did I own the car at the time. From what I've read 5w30 is what gm recommended on new cars? For high mileage cars I've seen people suggesting 10w40. Would 10w40 be a good idea to run? Currently 170,000 miles on stock engine.

 

I run 5W-30 High Mileage full synthetic. Mobil 1. Works well.

 

I don't run anything less than a 10w40 in any engine I drive. Viscosity is chosen based on load requirements. I drive cars hard - really hard. So nothing less than a 10w40. If you drive around like grandma then 0w20 will work fine. For an average daily driver, and for best economy and emissions, the OE recommendation was 10w30 on the engine originally. Now manufacturers would build the same engine with the same clearances and it would be rated for 5w20 synthetic.

We run 5w40 or 10w40 in most everything (performance shop) and anything with really high HP capability (like over 200 HP/liter) we run Amsoil Dominator 15w50.

BMW runs 10w60 in all their M series engines. Because LOAD.

Clear as mud?

I run Amsoil 10w40 Premium Protection in my 170k LB9.

GD

 

Yep. So do I.

 

I ran 10-40 M1 in my 170k LB9 but the oil pressure was a bit high. I don't driver her hard any more. I went back to using 5-30 M1 Hi Mileage.

 

Thanks for all the information. Hope the thread helps others too. I'll most likely go with 5w30 high mileage

 

http://speedtalk.com/forum/viewtopic...c1c1c3#p433871

 

OR:

http://speedtalk.com/forum/viewtopic...c1c1c3#p433871

Most technically inclined gearheads understand the value of real world, motor oil “load carrying capacity/film strength” testing. The results show us how various oils compare when it comes to wear protection. And we can use that information to make an informed decision as to which oil we want to select for our engines.

Though, there are some folks who are extremely set in their beliefs about what they’ve always been told and read, regarding high zinc oils providing excellent wear protection. But, the truth is, like all things in life, motor oils are NOT all created equal. And some oils are simply better than others, no matter what their zinc levels are. Anyone would have to be delusional to think otherwise. And “Wear Testing”, RATHER THAN ZINC LEVELS ALONE, can show us how various oils stack up against each other regarding wear protection capability, as you will see in the real world test data below.

Some folks, who REALLY believe the notion that more zinc in their oil will provide more wear protection, often throw a tizzy fit and get very nasty when test data shows a low zinc oil providing better wear protection than a high zinc oil. But, the fact is, behavior like that will NOT change the facts regarding what oils provide excellent wear protection and what oils do not. However, to keep everyone’s blood pressure down this time, we’ll look at ONLY HIGH ZINC OILS here. That way, all the oils are on an even playing field. However, true zinc lovers will no doubt be disappointed, because not all high zinc oils tested well, even though they all have plenty of zinc.

And keep in mind for comparison with the oils below, that earlier oil industry testing has found that above 1,400 ppm, ZDDP INCREASED long term wear, even though break-in wear was reduced. And it was also found that ZDDP above 2,000 ppm, started attacking the grain boundaries in the iron, resulting in camshaft spalling. So, no matter what zinc fans might “believe”, there is such a thing as "too much of a good thing".

The following group of 40 oils have zinc levels above 1100 ppm, and are ranked according to their “load carrying capacity/film strength”, or in other words, their “wear protection capability”, at 230*F. The tests were repeated multiple times for each oil, and even though all the results for each oil were consistent within a few percent, those results were averaged to arrive at the most accurate and representative final psi numbers shown below. And every single oil was tested EXACTLY THE SAME, so they all had the same opportunity to perform as well as their chemical formulation would allow.

But, before we get into the ranking list of those 40 oils, let’s take a closer look at one of those oils in particular. The oil is:

10W40 Summit Racing Premium Racing Oil, API SL conventional
The bottle makes some bold claims, such as:

* Double the zinc for superior flat tappet cam protection.

* The additive package contains 1800 ppm ZDDP, providing levels of protection unattainable from conventional motor oil. Provides excellent protection from metal to metal contact.

Problem is, this oil fell FAR SHORT of living up to that inflated boasting. These claims were obviously created by the Marketing Department with no regard for what this oil can actually do. This oil ranked a pathetic 85th out of the 94 new oils I’ve tested so far. And it ranked only 34th out of the 40 oils examined here. Once again, here is an oil with high levels of zinc that DID NOT help it perform very well, even among other high zinc oils. Buyer beware. Motor oils are among the worst products for false advertising.

Now let’s consider the claim on its bottle of 1800ppm ZDDP. Since Oil Companies typically don’t publish the ZDDP values of their oil, I sent this oil to Professional Lab, ALS Tribology in Sparks, Nevada, to see just what is really in it, and to see how that claim of 1800ppm ZDDP compares to reality. Here are the results that came back:

zinc = 1764 ppm
phos = 1974 ppm

NOTE: Most of the time, an oil’s zinc level is higher than its phos level, but the phos level here is greater than the zinc level. That is NOT a typo. That is how this oil’s results came back from the Lab. I’ve seen phos levels higher than zinc levels in approximately 40% of all the oils I’ve sent in for component level Lab Testing. So, it varies and just depends on a particular oil’s formulation. And the values listed below are all just the way they came back from the Lab.

If you average the zinc and phos values of this Summit Racing Oil, you come up with 1869 ppm. And that value is of course more than the 1800 ppm ZDDP claimed, so it appears they’ve averaged the values and then rounded down to the nearest 100 ppm, to be on the conservative side.
And since the ZDDP values are not usually available for most oils, we’ll calculate the ZDDP values for all the oils below, in the same manner as this oil, which should get us very close, if not right on target. But, for quick and dirty mental calculations, you can just figure the ZDDP value as approximately half way between the zinc and phos levels.

Here’s the ranking list:

Wear protection reference categories are:

*** Over 90,000 psi = OUTSTANDING protection

*** 75,000 to 90,000 psi = GOOD protection

*** 60,000 to 75,000 psi = MODEST protection

*** Below 60,000 psi = UNDESIREABLE
The higher the psi number, the better the wear protection.

1. 10W30 Lucas Racing Only synthetic = 106,505 psi
zinc = 2642 ppm
phos = 3489 ppm
ZDDP= 3000 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

2. 10W30 Valvoline NSL (Not Street Legal) Conventional Racing Oil = 103,846 psi
zinc = 1669 ppm
phos = 1518 ppm
ZDDP = 1500 ppm
NOTE: Due to its very low TBN value, this oil is only suitable for short term racing use, and is not suitable for street use.

3. 10W30 Valvoline VR1 Conventional Racing Oil (silver bottle) = 103,505 psi
zinc = 1472 ppm
phos = 1544 ppm
ZDDP = 1500 ppm

4. 10W30 Valvoline VR1 Synthetic Racing Oil, API SL (black bottle) = 101,139 psi
zinc = 1180 ppm
phos = 1112 ppm
ZDDP = 1100 ppm

5. 30 wt Red Line Race Oil synthetic = 96,470 psi
zinc = 2207 ppm
phos = 2052 ppm
ZDDP = 2100 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

6. 10W30 Amsoil Z-Rod Oil synthetic = 95,360 psi
zinc = 1431 ppm
phos = 1441 ppm
ZDDP = 1400 ppm

7. 10W30 Quaker State Defy, API SL semi-synthetic = 90,226 psi
zinc = 1221 ppm
phos = 955 ppm
ZDDP = 1000 ppm

8. 10W30 Joe Gibbs HR4 Hotrod Oil synthetic = 86,270 psi
zinc = 1247 ppm
phos = 1137 ppm
ZDDP = 1100 ppm

9. 15W40 RED LINE Diesel Oil synthetic, API CJ-4/CI-4 PLUS/CI-4/CF/CH-4/CF-4/SM/SL/SH/EO-O = 85,663 psi
zinc = 1615 ppm
phos = 1551 ppm
ZDDP = 1500 ppm

10. 5W30 Lucas API SM synthetic = 76,584 psi
zinc = 1134 ppm
phos = 666 ppm
ZDDP = 900 ppm

11. 5W50 Castrol Edge with Syntec API SN, synthetic, formerly Castrol Syntec, black bottle = 75,409 psi
zinc = 1252 ppm
phos = 1197 ppm
ZDDP = 1200 ppm

12. 5W30 Royal Purple XPR (Extreme Performance Racing) synthetic = 74,860 psi
zinc = 1421 ppm
phos = 1338 ppm
ZDDP = 1300 ppm

13. 5W40 MOBIL 1 TURBO DIESEL TRUCK synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4 and ACEA E7 = 74,312 psi
zinc = 1211 ppm
phos = 1168 ppm
ZDDP = 1100 ppm

14. 15W40 CHEVRON DELO 400LE Diesel Oil, conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM, = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
ZDDP = 1300 ppm



So, as you saw above, the highest ranking high zinc oil that provided the BEST WEAR PROTECTION of this group of 40 high zinc oils, had 3000 ppm ZDDP. But, the lowest ranking high zinc oil had one third MORE ZDDP at 4000 ppm. Even though this lowest ranked oil had far more zinc in it, it provided LESS THAN HALF AS MUCH WEAR PROTECTION, making it by far the worst of all 40 oils tested. Then the 4th place oil had only 1100 ppm ZDDP, and the 7th place oil had only 1000 ppm ZDDP.

So, the results above show 2 distinct things:

1. My tester and test procedure have no problem at all showing excellent performing high zinc oils. Therefore, no one can justifiably argue that my testing somehow works against high zinc oils. The absolute fact is, my oil testing performs worst case torture testing on motor oil. So, an oil HAS TO BE GOOD to produce good results. And we saw many high zinc oils with excellent results here. So, when the naysayers slam the value of my testing, they’re also saying at the same time, that high zinc oils are no good, since my testing shows excellent high zinc oils to provide excellent protection. They can’t have it both ways.

2. This is ABSOLUTE PROOF that not all high zinc oils have equal wear protection capabilities, which is the whole point I’ve been making for well over a year now. And why would anyone think that all high zinc oils are good? Not all tires are good. Not all cylinder heads are good. Not all camshafts are good. The world just doesn’t work that way. Some high zinc oils are quite good and provide excellent wear protection, while other high zinc oils are not good at all, and provide rather poor wear protection. It just depends on the particular oil in question. And that makes it totally clear here, that you simply CANNOT predict an oil’s wear protection capability by looking only at its zinc level. Life is just NOT that simple. If you only look at zinc levels, that is no better than guessing. So, if anyone tells you that you need high levels of zinc for more wear protection, even if it comes from a Cam Company, don’t believe a word of it. Because as you can see above, they have no idea what they are talking about. Would you really want to use the 40th ranked last place oil simply because it has more zinc than the number one ranked oil here? That is just what you’d be doing if you believed the incorrect advice about only looking at zinc levels. The ONLY way to know for sure how much wear protection any given oil can provide, is to look at “dynamic wear testing under load” results, such as I have provided above.

My oil testing data is very similar in concept to dyno testing an engine. An engine dyno test is also dynamic testing under load. For the guys who just want to look at a motor oil zinc level reference chart, that is like looking at an engine’s build sheet instead of its dyno print out. You can decide for yourself which provides more meaningful information.

540 RAT

What is ZDDP in oil?

Zinc dialkyldithiophosphate (ZDDP) is the most commonly used anti-wear additive in motor oils. It contains both zinc and phosphorus components that work together to provide anti-wear protection and minimize lubricant breakdown.

 

Just remember that multi's have a light and heavy component, If you don't use (your vehicle) in cold environments, you don't need the light component. If you do, however, remember that the light component is still quite tenacious in the cold until things warm up, then the heavy component can function.

I wouldn't run anything in anything I care about that doesn't protect below 90,000 psi....

 

p.s. I use a 10-40 VR-1 silver....