Jay2000

I found this article, it is interesting on the differences of the weights in amsoils oils and why amsoil does recommend 0-30w in our cars. I thought everyone would want to read this. I am staying with 0-30, it works for me and I am happy with the results, that does not mean everyone should use it. It is your own personal beliefs that matter.




Which 30 Weight Oil Do I Use, 0W-30, 5W-30 or 10W-30?

Direct from the ONLY Degreed Mechanical and Truck/Automotive Engineers on the net with 19 years experience specializing in engine, powertrain/chassis engineering, performance and synthetic motor oil lubrication and filtration right here in Detroit, MI.

We get asked this question so often that we have included this special page dedicated exclusively to answering the question.

AMSOIL 0W-30, 5W-30 and 10W-30 synthetic motor oils are ALL 30 weight oils. The answer is that ANY one can be used regardless if your vehicle owners manual says to use, for example, a 5W-30. "W" means winter. In winter weather the 0W oil will flow like a 0W oil, and the 5W will flow like a 5W oil and a 10W will flow like a 10W oil just until the engine warms up. In order to understand the differences one has to first understand that the numerical values given to these various weight oils are strictly empirical numbers. For example, 0W does not mean that the oil has no weight. That is one of the reasons why we say it is strictly an empirical number.

In order to determine the differences between the three oils one has to look at the kinematic viscosity of each lubricant. The kinematic viscosity is essentially the amount of time, in centistokes, that it takes for a specified volume

of the lubricant to flow through a fixed diameter orifice at a given temperature.

Let's compare the kinematic viscosity of the three AMSOIL lubricants:

AMSOIL 0W-30 is 57.3 cST @ 40 deg. C, & 11.3 cST @ 100 deg. C

AMSOIL 5W-30 is 59.5 cST @ 40 deg. C, & 11.7 cST @ 100 deg. C

AMSOIL 10W-30 is 66.1 cST @ 40 deg. C, & 11.7 cST @ 100 deg. C.

As you can see from the data above the kinematic viscosities are extremely close. Therefore, whether you use the 0W-30, 5W-30 or the 10W-30 is strictly a matter of choice. With the small differences in kinematic viscosity you would be hard-pressed to detect these differences on initial engine start-up without specialized engine test equipment.

All three oils are excellent motor oils and ANY one can be used in a vehicle which requires either a 0W-30, 5W-30 or 10W-30 oil as well as in several other engine applications including an engine which recommends a 5W- 20 oil.

AMSOIL Series 2000 0W-30 Severe Service motor oil is one of the best synthetic lubricants AMSOIL manufacturers for gasoline engine passenger vehicles and light trucks. The molecular and chemical technology used to develop this oil was derived from AMSOIL's Racing Oil. It is a 35,000 mile/1-year motor oil. This is the same oil used by numerous police vehicles and severe duty fleets nationwide. In fact, many national racing teams use the 0W-30 for the qualifying event, then they change to the AMSOIL 20W-50 Racing Oil for the race. The extra horsepower and friction reduction from the 0W-30 often assists a race driver in attaining a better starting position. In fact, we know exactly which race teams use it, but cannot disclose that information.

This leads to the next topic: many people also ask us if the 0W-30 is too thin a viscosity oil for high ambient temperature operation. The answer is absolutely not! Thicker viscosity oils are not always necessarily better since in addition to its' various engine lubrication functions, an oil must also effectively transfer heat. Only about 60% of an engines cooling is performed by the engine coolant, and only on the upper half of the engine. The remaining 40% of an engines cooling is performed mainly by the engine oil.

Although a vehicle that is recommended to use a 30 weight oil can also use a 40 weight oil, it is usually not needed. You will gain absolutely no benefit from using a thicker viscosity oil if it is not needed. The only time we recommend a 40 weight oil, such as AMSOIL's 10W-40, to a customer in a passenger car or light truck application is if the vehicle's engine is excessively worn and consumes oil at a higher than normal rate or if the vehicle is being used for very severe duty, high load, high temperature applications.

We hope this brief discussion has answered your questions. If we have not sufficiently answered your questions or if you would like an additional explanation or recommendation for your specific application, please e-mail us at: dave@performanceoiltechnology.com

This exceptional material is unique to Dave Mann, Truck/Automotive Engineer and not for unauthorized use. Special undetectable methods are used that will identify any of my material copied and published to the web.

I have been a Ford Engineer and Detroit MI Truck/Automotive Engineer and Lubrication Specialist for over 19 years and have had issues with others copying many years of my work and engineering knowledge. This notice and detection system effectively stops this activity. My goal is to serve you, the customer, by assisting you with your vehicle and lubrication related questions via this exceptionally unique website.

AMSOIL is the undisputed leader in synthetics...

slipstream444

If the benefit was lasting ... they'd keep the 0W30 in the car for the entire race.

The fact is 0W30 will break down quickly ender the stress of racing. Many racecars see 9000+ RPM. Many S2000s see 9000 RPM too ... hmmm.

The S2000 lists a higher viscosity oil as the 'norm' because some of the same considerations made in race engines are made in the S2000s engine(s). This includes accommodating for a thicker oil film to support the rotating assemblies in the engine. If you drive your S2000 hard (see the redline on a regular basis), do you want a 0W30 supporting these expensive components, or something a little thicker? I vote for thicker (within reason - the logic works both ways - as in you can go too thick!).
When I would change the oil in my Civic (when using the 0W30), it came out seemingly as thin as hot ATF on a hot summer day. This was a 117 bhp D series motor (HX) that redlined below 7000 RPM. What do you think an S2000 would do to that oil on a hot summer day or track event?

Ludedude

Bingo

Jay2000

A couple more light reading tidbits comparing 0-30, 10-30, and the 20-50 racing oil they are talking about.

AMSOIL Series 2000 Synthetic 0W-30 Motor Oil (TSO)

Kinematic Viscosity @ 100

oakfloor

Bingo.. but who runs there s2k @ 9000rpm for two hours? or 500 miles? 0w-30 will work just fine for daily use. if you road race it, then use a "racing oil"

slipstream444

You can look at those numbers all day long (and I have) - your post was painful!

If you look at the 4-ball test, all three tests were different - as in force applied (for the 20W50 - which isn't even a player for the S2000), temp, and RPM. Therefore it's hard to say which one is actually better. You may say, "higher temp is harder on the oil" - that's not necessarily so. Some oils perform better at warmer temps.

How about the RPM difference -
I'll defer to a simplified BG bearing wear test attempting to demonstrate how one of their additives outperforms synthetic oils - as the RPM increased, their product actually seemed to produce a better film and protected better. However, after everyone left the demonstration - I sat and talked to him and watched him clean the test machine bearing surface with brake cleaner. He then looked around and demonstrated that the brake cleaner worked better than all the oils (for a short period of time) at preventing a wear scar.
The rub on this is you can tailor a test to bring out the best in your product. The four-ball test works at low RPM and does not demonstrate what (for example) bearings deal with - especially at high RPMs. How many of you lug your car around at 1200 or 1800 RPM.

One of the most important tests where the 0W30 does worse than any of their other oils is in the Noack volatility test. This was another reason I stopped using the 0W30 in my Civic ... it left a residue behind under my valve cover. The 5W30 did not. The S2000 is known for using oil. Using the 0W30 will only increase the level of consumption. Additionally, the 0W30 got dark 1500 miles before the 5W30 did.
The bottom line is use what makes you happy. In the end you're just throwing your money away.

riceburners2001

slipstream444, what do u run in your s?

slipstream444

I run 5W30 in the winter (although I'm considering switching to 10W30), and I used to use the Euro 5W40 in the summer. I read yesterday that Amsoil recently reformulated their 5W40 to include some new diesel VW specs, and according to their data ... it doesn't provide as much wear protection (the 4-ball test results changed significantly). I'm thinking along the lines of 10W30 or 10W40 for my summer oil. I have another 2 years to decide My S2000 is in hard storage.