rrounds

I changed my oil 4 times last year, but I put over 35k miles on it last year. I go about 8k miles on M1 and a oversize filter. Have not had to add any oil and I also run my car hard on the mountain and coast roads that I drive. My SSEI runs 10k on the oil, uses about 1/2 qt. in that time and has 240k miles(bought the car new in 2000). I don't expect any less of my "S".

ROD

JackS

I have little doubt that any modern oil and synthetic in particular, is good for 10k or more. At present, I'm using M1-EP and following the maintainance minder of 5-6 thousend miles. I also know that I'm probably switching out perfectly good oil but using the MM guarantees I'll never forget. Life is easier this way.

SpitfireS

At a cold start or an operating temp start?
Does it go away with some revs?

rob-2

This. Had a family friend who was a chemical engineer for a large oil company change their oil once/year. Their honda went 320K before they gave it away to a kid. Car burned no oil to speak of. They told me most of this oil debating is complete waste of time. In the lab you see a lot of things and in the real world, even most of the so-so oils will still provide enough protection to have the lubricated surfaces outlast everything else. If you want to keep your car running long they told me oil full and go easy on it until it's well warmed up. That will go a lot further than the 1-3% difference i real-world protection.

I'm actually surprised that you're not all sporting 5w40 which has the low end protect as well as the high end protection. Why aren't people concerned about their oil thinning and causing bearing wear?

s2000maniac

yes it goes away with revs. its worse at cold start up but even when the car is fully warmed up i can still hear it.

s2000maniac

so with 0w-30 the oil will thin out and cause bearing damage?

zeroptzero

talking about oil is just a pass-time for many of us, at the end of the day very few of us know anything with any degree of certainty. I tend to agree with your chemist friend. I know family members who ran vehicles with very few oil changes and those vehicles all went 200k miles+, and the bodies usually fell apart before the engines.

FWIW I ran a 5w40 for one year, it seemed to perform similarly to a 5w30 that I also ran, I didn't notice much difference. Thinning or shearing oil on this engine doesn't seem to have much of an effect on wear, many 30 weights end up being close to 20 weights after a good shear that this engine puts them through. All the fears people had of 20 weight oils have been dispelled now with millions of engines running 20 weight oils for many years and no evidence of shortened engine life or increased wear. I think this engine could run a 20 weight for normal daily driving purposes if someone wanted to do it, I recall one member running a 20 weight and it tested out perfectly fine. Dr. Haas puts his money where his mouth is by running a 20 weight oil in his Ferrari that specs a 40 weight, which is a pretty good test for me.

BirdShot

talking about oil is just a pass-time for many of us, at the end of the day very few of us know anything with any degree of certainty. I tend to agree with your chemist friend. I know family members who ran vehicles with very few oil changes and those vehicles all went 200k miles+, and the bodies usually fell apart before the engines.

FWIW I ran a 5w40 for one year, it seemed to perform similarly to a 5w30 that I also ran, I didn't notice much difference. Thinning or shearing oil on this engine doesn't seem to have much of an effect on wear, many 30 weights end up being close to 20 weights after a good shear that this engine puts them through. All the fears people had of 20 weight oils have been dispelled now with millions of engines running 20 weight oils for many years and no evidence of shortened engine life or increased wear. I think this engine could run a 20 weight for normal daily driving purposes if someone wanted to do it, I recall one member running a 20 weight and it tested out perfectly fine. Dr. Haas puts his money where his mouth is by running a 20 weight oil in his Ferrari that specs a 40 weight, which is a pretty good test for me.
[/quote]

I see literally hundreds of engine oil samples a day (along with gears, hydraulics, compressors, turbines, fuels) and have access to millions of samples including new lube references. In my experience, the amount of viscosity loss in an engine oil that CANNOT be explained by fuel dilution, "shearing", is usually fairly small and rarely seems to correlate with increased engine wear.

The thinking is that the wider the range, the more potential for shearing. I won't argue this, but the amount of shearing that happens and it's effect's are fairly insignificant. The higher quality the oil, even less potential for degradation.

In my opinion, I would use a quality 0w-30 with confidence.

zeroptzero

talking about oil is just a pass-time for many of us, at the end of the day very few of us know anything with any degree of certainty. I tend to agree with your chemist friend. I know family members who ran vehicles with very few oil changes and those vehicles all went 200k miles+, and the bodies usually fell apart before the engines.

FWIW I ran a 5w40 for one year, it seemed to perform similarly to a 5w30 that I also ran, I didn't notice much difference. Thinning or shearing oil on this engine doesn't seem to have much of an effect on wear, many 30 weights end up being close to 20 weights after a good shear that this engine puts them through. All the fears people had of 20 weight oils have been dispelled now with millions of engines running 20 weight oils for many years and no evidence of shortened engine life or increased wear. I think this engine could run a 20 weight for normal daily driving purposes if someone wanted to do it, I recall one member running a 20 weight and it tested out perfectly fine. Dr. Haas puts his money where his mouth is by running a 20 weight oil in his Ferrari that specs a 40 weight, which is a pretty good test for me.
[/quote]

I see literally hundreds of engine oil samples a day (along with gears, hydraulics, compressors, turbines, fuels) and have access to millions of samples including new lube references. In my experience, the amount of viscosity loss in an engine oil that CANNOT be explained by fuel dilution, "shearing", is usually fairly small and rarely seems to correlate with increased engine wear.

The thinking is that the wider the range, the more potential for shearing. I won't argue this, but the amount of shearing that happens and it's effect's are fairly insignificant. The higher quality the oil, even less potential for degradation.

In my opinion, I would use a quality 0w-30 with confidence.
[/quote]

awesome info

INDYMAC

I think this is an excellent breif on viscosity terms and understanding of all aspects, and it's not too technical:

http://www.zddplus.com/TechBrief13%2...0Viscosity.pdf

Here is an HDEO Oronite (additive company) presentation (for diesel applications) on their VII products and shear rates:

ftp://ftp.astmtmc.cmu.edu/docs/diese.../0601ATT18.PDF